The Starrett Buy American thread reminded me to chime in with a personal
experience on:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=47257
I've had mine for two years now - it's great! Used enough to be on Battery
#3.
While I don't have a machinist's reference point to calibrate it to - I've
measured a number of off the shelf items - drill bits, chisels, screws, etc.
This unit is within a few thousands of what you'd assume it would report. As
for accuracy, it again seems to put up data repeatable to a thou or so...
If all the units are as nice as mine, I think it's a great buy at $16.
On Sun, 12 Sep 2004 20:38:39 GMT, Unisaw A100 <[email protected]> wrote:
>AArDvarK wrote:
>>Take a click:
>>http://www.rit.edu/%7Euphysics/VernierCaliper/caliper.html
>
>
>Absolutely useless. Not a thing said about how to properly
>ground a caliper.
>
>UA100
You don't need to ground a caliper, that's just a myth. Nobody has ever
presented a single example of a shop explosion caused by an ungrounded
caliper.
:-)
"AL" <[email protected]> wrote in message news:<c3x0d.167747$Fg5.165667@attbi_s53>...
<snip>
> Many tools (such as the TS Aligner Jr, and numerous
> height gauges used to set jointer/shaper blades) use outdated designs which
> assume only one Starrett (or Starrett like) indicator at $100+ (ie. you only
> have one). But these tools could do a far better and quicker job if they
> were designed to use 2 or 3 indicators.
I'd take exception to this statement. With any experience or training
in Metrology, a person can easily see right through this reasoning
pretty quickly. Or, if you just try an idea like this you'll
immediately recognize it's folly. Multiple indicators don't make
anything better or quicker or easier.
Ed Bennett
[email protected]
Well "AL":
Perhaps you should elaborate even more about your ideas! I'm thinking
that you should try them and then make an honest report back to the
group on how they worked. Maybe after you have actually tried these
things they won't seem like such great ideas.
I guess you got my dander up because you specifically mention my
product (TS-Aligner Jr.) and how much it could be "improved" with this
idea of yours (multiple indicators). I think that it's enough of a
lesson if you are forced to try your own idea and report the results
back to the group - honestly. Then maybe you might think twice about
trying to fool members of this group into thinking you know anything
about machinery alignment or Metrology.
Ed Bennett
[email protected]
http://www.ts-aligner.com
"AL" <[email protected]> wrote in message news:<FhJ0d.173062$Fg5.113792@attbi_s53>...
> Consider the gauge used to set jointer blades.
<snip>
> Now consider a modern version that holds two dial indicators spaced about 4"
> apart....
<snip>
> As for a table saw alignment tool like the TS Aligner Jr,...
<snip>
> Consider an improved version which has two indicators spaced about 8" apart
<snip>
"AL":
OK, I guess you are asking me to help you get started thinking about
the problems with your ideas. I don't mind doing this, as you've
pretty much admitted in the request that you haven't tried your ideas
(or even given much thought to their feasibility).
Whenever you have one measurement device on one fixture you have a
stable reference. All subsequent measurements using this same exact
setup will be relative to this same exact reference. All the
individual variables which make up that reference will be included
identically in every measurement so that their relative effect from
measurement to measurement is completely nullified. If you introduce
a second measurement device and attempt to make the same measurements
in a repeatable manner then you create a second reference. All of the
variables making up both references become significant. Each variable
must be addressed individually and it's contribution to the results
quantified and/or eliminated. If this is not done, then you will
never know if the readings accurately represent the objects being
measured or the effects of these uncontrolled variables.
To put it another way, it might seem rather inconvenient to use one
measurement device and one fixture to do multiple measurements, but it
is an effortless method which guarantees that each measurement is done
with an identical setup. No external variables will influence the
results. If two measurements come out differently, it's because the
objects being measured are different. If two measurements come out
the same, it's because the two objects being measured are identical.
For example, in your jointer knife alignment idea, a rather elaborate
calibration procedure would be necessary to ensure that the two dial
indicators were providing the same readings for any given measurement.
Just because they read the same for one measurement pair (say, the
top of the outfeed table) doesn't mean that they actually provide the
same measurements. What if one indicator isn't tilted at the exact
same angle as the other? What if one side of the fixture flexes more
than another? What if the measurement force of one indicator is more
than the other? What if the two stylus points are slightly different
sizes or shapes?
Yes, it is possible to create a fixture, choose indicators, and
account for all the possible variables which can significantly alter
the results so that two identical measurements can be performed at the
same time using two indicators. But why would you ever want to go to
all this trouble when you could just use one indicator on one fixture
to make two measurements?
Also, I just can't imagine trying to manage two indicator styli on a
knife edge at the same time. You may decide that it's good enough to
just worry about one at a time but then where's the advantage of
having two indicators?
All of the above applies to your tablesaw alignment example too. In
addition, you have assumed that blade warp is always bi-lateral and
symmetrical. Sorry, that's a bad assumption. It's also not valid to
assume that the arbor and flange (what you call the "fixed washer on
the arbor") have no runout. You can obtain different readings on your
two dial indicators and not be able to discern if they are due to
misalignment, runout, warp, or one of the variables mentioned above.
If you obtain identical readings on your two dial indicators, there is
no assurance that proper alignment has been obtained. This is truely
a case in which no amount of "factory calibration" will help. It's a
setup which voilates all the applicable Metrological rules.
An alignment tool must be able to perform it's task without being
adversely affected by these uncontrolled variables. Making two
measurements with a single indicator setup using a fixed reference
(the dot on the blade) is completely immune to all of the variables
mentioned. When the two readings are the same then the saw is
definitely aligned beyond any reasonable doubt.
This is just the tip of the iceberg. These are just conceptual level
reasons why your idea is impractical. There are lots of other things
to consider which you'll discover when you attempt to build your
prototypes. I would be more than happy to discuss these things and
I'm sure that there are others in the group who would be interested in
reading along. But, we must agree not to name specific products and
identify them as "inferior" when we really don't understand the the
most basic principles of the topic at hand. Agreed?
Thanks,
Ed Bennett
[email protected]
http://www.ts-aligner.com
"AL" <[email protected]> wrote in message news:<SJt2d.314009$8_6.193390@attbi_s04>...
> Ed,
>
> In your two posts, all I see is a personal attack. Fair enough because I
> insulted your product. However I don't see anything that says why the
> jointer and table saw gauge that I described won't work.
>
> I fully intend to build them and will report back on how they turned out.
> Right after I install the DRO on my planer. Unfortunately it will be a few
> months.
>
> I'll build the jointer gauge pretty much as I described. But I'll be
> building a few different table saw gauges. One will be as I described. In
> addition, I want some way to get the two indicators to touch the fixed
> washer on the arbor, so that I can remove the blade and not worry about it
> being warped. I'm still thinking about how to do that.
Well, this is actually a bit different. Here there are two indicators
measuring two different things (x movement and y movement) providing
two different values (x and y) to locate a single object in two
dimensions. The x and y readings are supposed to be completely
independent of eachother (unless your lathe is a bit difficient).
There are times where a "comparator" of sorts will be constructed to
provide differential measurements between an unknown and a fixed
standard. Some of my electronic gaging equipment has inputs for this.
Very complicated. Very expensive. Often a setup like this is used
in the calibration of gage blocks. I tried to do it once and failed
pretty miserably. I just don't have the facilities or capabilities to
eliminate all the variables. You think it's easy until you try it!
Thanks,
Ed Bennett
[email protected]
http://www.ts-aligner.com
[email protected] wrote in message news:<[email protected]>...
> unless you're measuring travel in 2 directions simultaneously on the
> cross slide on your metal lathe.
>
> which of course we wouldn't do here. it's not woodworking.....
Hello again AL,
As I said, it is possible to create a fixture to do what you want (on
the jointer at least) but the task is not easy and accurate results
aren't going to come cheap.
"AL" <[email protected]> wrote in message news:<NTO2d.62407$MQ5.26300@attbi_s52>...
> Regarding the jointer gauge, what I plan to do is get an angle plate of the
> right size, drill and tap two holes on the sides and then mount two
> indicators.
Not bad. So, as you can see already, the fixturing (the angle plate
in this case) will be the most expensive element of your design. For
the most part, this is always true. The first logical question
involves choosing the "right size" for your angle plate. Since the
indicators will be attached to the sides, they are mounted in fixed
locations which are determined by the size of the angle plate. One
size won't fit all jointers. So, several models would be needed.
It's not a very attractive solution for someone with more than one
jointer (or someone planning to upgrade to a larger model someday).
It's also a "one function" solution. It is designed for jointers only
(just imagine trying to calibrate this for planers). Expensive,
single function products are not a very attractive to prospective
customers.
> Both indicators first touch the outfeed table. The dials get
> zeroed.
Unfortunately, this doesn't guarantee that the two indicators provide
the same measurements. If you are sure that your outfeed table is
sufficiently flat then this works. If you are not sure, then it's
equivalent to calibrating your instrument using an unknown standard.
A good calibration instrument needs to be immune to imperfections in
the machinery. It needs to work for everyone who follows the
instructions properly. If good alignment is possible, then the
instrument should facilitate it. If good alignment is not possible,
then the instrument should not fool you into thinking you have good
alignment.
> Then the gauge is moved forward to touch the knife edge. Because
> the goal is to get the dials to read zero again (ie. I'm not measuring a
> linear distance. Cosine of the angle multiplied by zero.), I don't see any
> effect if either indicator were slightly tilted (even thought it will be
> very easy to be sure they are not).
Just give it a try and let us know how you make out. It's not a
matter of the effect that tilt will have on one indicator's ability to
provide absolute linear measurements. Remember, you're trying to get
two indicators to read the same thing when they are measuring the same
thing. Exaggerate the possibilities in your mind or just give it a
try and see what happens. If the difference in readings is less than
0.001", can you be sure that the difference in the objects being
measured is less than 0.001"? You can always check the accuracy of
your results using the single indicator setup (which is, in fact,
quite immune to tilt so long as you use a spherical indicator point).
I also think you're going to have a lot of difficulty ensuring that
the dial indicators are aligned (have the same tilt).
> The angle plate is identical on both
> sides so one side wouldn't flex more than the other. The spring tension on
> the indicators may not be the same, but won't have enough force to either
> lift the angle plate, or lower the knife.
The fixturing is definitely rigid enough and quite heavy (though not
very adjustable). While two indicators may respond differently to
different measurement pressures you probably don't have to worry about
this too much.
> The stylus points won't matter
> because the part of the point that initially touched the outfeed table, will
> be touching the edge of the knife. However, I may use disk-shaped points to
> make it easier to put the point on the knife.
Actually, the stylus points make a huge difference - especially if you
plan to use flat rather than spherical indicator points (a very common
mistake). Imagine the effects of indicator tilt when using a flat
stylus. If there is any tilt in either direction, then the reading
will vary significantly depending on where the knife contacts the
surface of the stylus. How will you determine if a difference in
readings is the result of misalignment or tilt related positioning of
the knife edge? Can you really ensure that the indicator point
touches the knife in the same spot that it contacted the table? Try
it and let us know how it works out. You can always use the single
indicator solution (with spherical indicator point) to check the
accuracy of the results.
> The table saw gauge is more complicated. I am assuming that a warped blade
> is cupped such that you can turn it so that the curve is in the vertical
> direction. I'm not sure how to describe this in words. Imagine looking at
> the blade from the side and seeing something shaped like a left bracket ( .
Yes, I know what you are talking about. It's called "bi-lateral
symmetry". You are assuming that there is an orientation of the blade
such that every point on one side of a centerline has a corresponding
point on the other side. You can probably find blades like this. You
might even own some. But, there is no guarantee that all blades will
exhibit bi-lateral symmetry.
> If the warpage is more like a ripple than a cup, then what I am proposing
> won't work. I'll have to measure a few of my blades and see just what they
> look like.
It could still be shaped like a cup (bi-lateral) but not be
symmetrical. Don't make the mistake of thinking that some small
sample of blades (yours for example) are representative of all blades.
> The only reason I mentioned your product by name was that everyone knows
> what I'm talking about when they hear it. If there was a popular brand of
> jointer gauge like the one I was talking about (Oneway and Powermatic make
> one--I've seen several more), I would have used that name. In retrospect,
> it was a bad idea.
Sure, I understand. And, I'm sure you understand why it's important
for me to defend the hard earned reputation of my products against
untested ideas which violate basic Metrological principles.
Ed Bennett
[email protected]
http://www.ts-aligner.com
[email protected] wrote in message news:<[email protected]>...
> null axis of the warp......
Yup! It's deja vu all over again!
I've purchased a number of these cheap angle plates for fixturing in
the shop. They are pretty handy but don't expect them to be very
accurate. Don't be surprised if they rock on a flat surface.
The proper choice of indicator point is Metrology kindergarden. A
flat stylus should only be used on a round surface. A round stylus
should only be used on a flat surface. A knife edge is basically a
flat surface (flat in one dimension anyway). To obtain reliable and
repeatable results, a round stylus is called for.
"Flat contact points have an important role but can be a serious cause
of error when improperly used" "Fundamentals of Dimensional Metrology"
by Ted Busch, 2nd Edition p.256, (c) 1989 Delmar Publishers Inc.
This is a great book by the way. A "must read" for anyone interested
in designing their own alignment and measurement fixturing. It can
still be found on Amazon for about $3.00. The latest edition will set
you back about $85.
Ed Bennett
[email protected]
http://www.ts-aligner.com
"AL" <[email protected]> wrote in message news:<b8b3d.69057$MQ5.52997@attbi_s52>...
> The angle plates I'm considering are in the $5 to $10 range--imported to
> match my imported indicators. I realize the disk shaped points require the
> indicators to be perpendicular. I just don't think it will be that hard to
> do. But I will experiment with both types of points.
>
"AL" <[email protected]> wrote in message news:<G9n3d.12211$wV.1976@attbi_s54>...
> Did I miss something?
Sorry Al. Yes, about a year ago there was a guy who came along with
his own tablesaw alignment procedure. He claimed that this procedure
enabled him to achieve repeatable 0.0001" accuracy on his tablesaw.
No, that's not mistake, one ten-thousandth of an inch accuracy - IN
WOOD! Of course, it took a monumental effort to get him to submit
samples of such claimed accuracy. And, of course, his own samples
(tested by an unbiased third party) proved him wrong. Turns out he
was using a 0.001"/div indicator to "guestimate" 0.0001" accuracy.
His "comparator stand" consisted of a China import dial indicator
mounted to a China import magnetic base. His "surface plate" was a
piece of 1/4" plywood on top of a contractor's style tablesaw. The
whole thing was liberally sprinkled with sawdust. I can probably dig
up the photo - send me email if you are interested.
One of the central themes in his alignment procedure was finding
something he called the "null axis of the warp". Basically, he was
convinced that blade warp was always bi-laterally symmetrical. In his
case, he believed that a line could be drawn across the surface of any
blade which was perfectly perpendicular to the arbor's axis of
rotation. Finding this line (the "null axis of the warp") was the key
to his (flawed) procedure.
Trust me Al, you're lucky you missed it. And, you wouldn't be in good
company to hang on to such flawed reasoning.
Ed Bennett
[email protected]
http://www.ts-aligner.com
"AL" <[email protected]> wrote in message news:<G9n3d.12211$wV.1976@attbi_s54>...
> Did I miss something?
Sorry Al. Yes, about a year ago there was a guy who came along with
his own tablesaw alignment procedure. He claimed that this procedure
enabled him to achieve repeatable 0.0001" accuracy on his tablesaw.
No, that's not mistake, one ten-thousandth of an inch accuracy - IN
WOOD! Of course, it took a monumental effort to get him to submit
samples of such claimed accuracy. And, of course, his own samples
(tested by an unbiased third party) proved him wrong. Turns out he
was using a 0.001"/div indicator to "guestimate" 0.0001" accuracy.
His "comparator stand" consisted of a China import dial indicator
mounted to a China import magnetic base. His "surface plate" was a
piece of 1/4" plywood on top of a contractor's style tablesaw. The
whole thing was liberally sprinkled with sawdust. I can probably dig
up the photo - send me email if you are interested.
One of the central themes in his alignment procedure was finding
something he called the "null axis of the warp". Basically, he was
convinced that blade warp was always bi-laterally symmetrical. In his
case, he believed that a line could be drawn across the surface of any
blade which was perfectly perpendicular to the arbor's axis of
rotation. Finding this line (the "null axis of the warp") was the key
to his (flawed) procedure.
Trust me Al, you're lucky you missed it. And, you wouldn't be in good
company to hang on to such flawed reasoning.
Ed Bennett
[email protected]
http://www.ts-aligner.com
"AL" <[email protected]> wrote in message news:<Hdn3d.71598$MQ5.26374@attbi_s52>...
> The gages sold by Oneway and Powermatic use flat disk shaped points.
Like I said, it's a common mistake. You'll see the same thing in
books, magazines and other products. It's unfortunate to see such
prominent examples. Knowledge and expertise are not pre-requesites
for selling something in this marketplace. Crap is super-abundant! I
suspect that some gages are outsourced by a Marketing department with
virtually no engineering input. There are also a plethera of hacks
selling very ill conceived products based on no formal (or even
informal) education whatsoever. It makes it very difficult for me to
differentiate my products.
> I will
> be trying several different shapes to see what works best. The rules be
> d*mned.
Don't be ignorant just because you see examples of other people being
ignorant. The "rules" are based on science.
> I also have the Fundamentals of Dimensional Metrology and think it
> is very good.
It's a great book to have. It's even better to read and understand
what it says. You'll find yourself in good company!
Thanks,
Ed Bennett
[email protected]
http://www.ts-aligner.com
On Sat, 11 Sep 2004 00:11:37 GMT, "patrick conroy"
<[email protected]> wrote:
>The Starrett Buy American thread reminded me to chime in with a personal
>experience on:
>http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=47257
>
>I've had mine for two years now - it's great! Used enough to be on Battery
>#3.
>While I don't have a machinist's reference point to calibrate it to - I've
>measured a number of off the shelf items - drill bits, chisels, screws, etc.
>This unit is within a few thousands of what you'd assume it would report. As
>for accuracy, it again seems to put up data repeatable to a thou or so...
>
>If all the units are as nice as mine, I think it's a great buy at $16.
>
I've been thinking about attaching one to my planer for quite some time,
but haven't pried open the wallet to buy one to drill holes in. This may
be the ticket if I can concoct an attachment method that doesn't look
totally jury-rigged.
Regarding the angle plates, the cheap ones I currently use don't rock on my
surface plate. I'm not sure if they are exactly perpendicular, but I don't
need them to be.
"Ed Bennett" <[email protected]> wrote in message
news:[email protected]...
> I've purchased a number of these cheap angle plates for fixturing in
> the shop. They are pretty handy but don't expect them to be very
> accurate. Don't be surprised if they rock on a flat surface.
>
> The proper choice of indicator point is Metrology kindergarden. A
> flat stylus should only be used on a round surface. A round stylus
> should only be used on a flat surface. A knife edge is basically a
> flat surface (flat in one dimension anyway). To obtain reliable and
> repeatable results, a round stylus is called for.
>
> "Flat contact points have an important role but can be a serious cause
> of error when improperly used" "Fundamentals of Dimensional Metrology"
> by Ted Busch, 2nd Edition p.256, (c) 1989 Delmar Publishers Inc.
>
> This is a great book by the way. A "must read" for anyone interested
> in designing their own alignment and measurement fixturing. It can
> still be found on Amazon for about $3.00. The latest edition will set
> you back about $85.
>
> Ed Bennett
> [email protected]
>
> http://www.ts-aligner.com
>
>
> "AL" <[email protected]> wrote in message
news:<b8b3d.69057$MQ5.52997@attbi_s52>...
> > The angle plates I'm considering are in the $5 to $10 range--imported to
> > match my imported indicators. I realize the disk shaped points require
the
> > indicators to be perpendicular. I just don't think it will be that hard
to
> > do. But I will experiment with both types of points.
> >
For one thing, you can't convert from mm to inches and visa versa
You also can reset the zero to add "more length" to a measurement, or get a
differential measurement quickly
Frank
AL wrote:
> I've had the 6" and 4" calipers for several years and really like them. The
> 4" fits nicely in my pocket.
>
> What's wrong with a vernier? They are difficult to read at an angle or in
> dim light. You can't zero them out when partially open to do a comparison
> reading. You can't switch to metric at the push of a button. And when
> taking dozens of readings, they take a long time. Comparing a digital
> caliper to a vernier is like comparing a calculator to slide rule.
>
> I've also been very happy with HF's dial indictors (normally around $13 but
> frequently on sale for around $7). Dial indicators are very useful when you
> have more than one. Many tools (such as the TS Aligner Jr, and numerous
> height gauges used to set jointer/shaper blades) use outdated designs which
> assume only one Starrett (or Starrett like) indicator at $100+ (ie. you only
> have one). But these tools could do a far better and quicker job if they
> were designed to use 2 or 3 indicators.
>
> "patrick conroy" <[email protected]> wrote in message
> news:[email protected]...
> > The Starrett Buy American thread reminded me to chime in with a personal
> > experience on:
> > http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=47257
> >
> > I've had mine for two years now - it's great! Used enough to be on Battery
> > #3.
> > While I don't have a machinist's reference point to calibrate it to - I've
> > measured a number of off the shelf items - drill bits, chisels, screws,
> etc.
> > This unit is within a few thousands of what you'd assume it would report.
> As
> > for accuracy, it again seems to put up data repeatable to a thou or so...
> >
> > If all the units are as nice as mine, I think it's a great buy at $16.
> >
> >
I've had one for a couple of years, I'm on my second battery. Great fot the
price.
patrick conroy wrote:
> The Starrett Buy American thread reminded me to chime in with a personal
> experience on:
> http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=47257
>
> I've had mine for two years now - it's great! Used enough to be on Battery
> #3.
> While I don't have a machinist's reference point to calibrate it to - I've
> measured a number of off the shelf items - drill bits, chisels, screws, etc.
> This unit is within a few thousands of what you'd assume it would report. As
> for accuracy, it again seems to put up data repeatable to a thou or so...
>
> If all the units are as nice as mine, I think it's a great buy at $16.
Much easier to read without my reader glasses.
AArDvarK wrote:
> > The repeatability is precision. Accuracy is how close to the real value
> > you get.
> > "0.900, 0.901, 0.899, 0.902, 0.898" is precision.
> > "1.00, 0.50, 1.50, 1.25, 0.75" is accuracy.
> > You want both. "1.000, 1.001, 0.999, 1.002, 0.998"
> > Anyway, for $16 I want one too. I'm considering a Stanley 136, because I'm
> > looking for "neighborhood", not accuracy and precision.
>
> Tell me, what is wrong with using a regular mechanical vernier caliper?
> Alex
On Thu, 16 Sep 2004 18:22:36 GMT, "AL" <[email protected]> wrote:
>What you call magic, I call child's play.
>
>The three indicators need to read the same to work. Adjusting them at the
>factory is child's play. Merely a setscrew that allows the indicator to
>slide back and forth.
>
>If you want to do your own calibration, you merely need to use a machinists
>square. One leg against the indicator stems, another leg against the edge
>of the holder (that has been machined square).
>
>I use indicators all the time. I don't handicap myself by doing things the
>traditional way.
I own I think 6 or 7 indicators. sometimes I set them up in multiples,
but never more than one to measure the same thing, which is what it
sounds like you are advocating. bloody waste of time, much like what
this thread has become.
tell you what. take some pictures of your setup and post them to ABPW.
'till then, this thread is dead as far as I'm concerned.
>
><[email protected]> wrote in message
>news:[email protected]...
>> On Thu, 16 Sep 2004 11:56:21 GMT, Jim Behning
>> <[email protected]> wrote:
>>
>> >How do you square the 3 dial jig in the chuck? One indicator in a
>> >locked chuck and all you have to do is a sweep to check. Does it take
>> >hours to establish that the jig is square? What jig does it take to
>> >make sure the 3 indicator jig is square or parallel or plumb or choose
>> >your word?
>>
>>
>> he's using magic- "factory calibrated to read the same".
>>
>> I don't think he's used indicators much.
>>
>>
>>
>>
>>
>>
>>
>> >
>> >"AL" <[email protected]> wrote:
>> >
>> >>Aligning a mill vise with two indicators would take longer because the
>jig
>> >>used to do the alignment was designed for one indicator (ie. clamp the
>> >>indicator in the chuck and sweep the fixed jaw). Imagine a jig that you
>> >>clamp in the chuck/collet/holder that holds 3 indicators (all factory
>> >>calibrated to read the same). The center indicator is centered with the
>> >>shaft in the chuck/collet/holder. All you have to do square the jig
>against
>> >>the table (ie. all 3 indicators read the same), clamp the spindle, then
>> >>adjust the vise so that the two outside indicators read the same as the
>> >>middle one. No more sweeping.
>> >>
>> >>"CW" <no adddress@spam free.com> wrote in message
>> >>news:[email protected]...
>> >>> Not at all. Dial indicators were developed by, and are used
>extensively in
>> >>> the metalworking industry. The reason for using a single gage is the
>> >>> elimination of variables. The cost of indicators has never been a
>factor
>> >>to
>> >>> them. They have always been relatively cheap. For someone using an
>> >>indicator
>> >>> for alignment at home, two might seem easier. For me (machinist),
>setting
>> >>> two indicators to do a simple alignment (mill vise, or tablesaw blade)
>> >>would
>> >>> increase the time to do the job.
>> >>> "AL" <[email protected]> wrote in message
>> >>news:n4a1d.183004$Fg5.53426@attbi_s53...
>> >>> > My whole point is that people who design the gauges are stuck with
>an
>> >>> > outdated way of thinking that says "dial indicators are expensive so
>my
>> >>> > design will only use one".
>> >>> >
>> >>>
>> >>>
>> >>
>>
>
> The repeatability is precision. Accuracy is how close to the real value
> you get.
> "0.900, 0.901, 0.899, 0.902, 0.898" is precision.
> "1.00, 0.50, 1.50, 1.25, 0.75" is accuracy.
> You want both. "1.000, 1.001, 0.999, 1.002, 0.998"
> Anyway, for $16 I want one too. I'm considering a Stanley 136, because I'm
> looking for "neighborhood", not accuracy and precision.
Tell me, what is wrong with using a regular mechanical vernier caliper?
Alex
On my Bridgeport clone, if I put the speed selector in neutral, I can turn
the spindle with one finger and either make it turn one or more revolutions,
or turn just the slightest amount. I don't have a 100hp CNC mill yet but
I'll figure something out when I get one (well into the future).
"CW" <no adddress@spam free.com> wrote in message
news:[email protected]...
> Even something as small as a Bridgeport would be damn difficult to
position
> with any precision by hand. Try it on a 100 horse power CNC.
On Fri, 17 Sep 2004 04:28:34 GMT, "AL" <[email protected]> wrote:
>Ed,
>
>In your two posts, all I see is a personal attack. Fair enough because I
>insulted your product. However I don't see anything that says why the
>jointer and table saw gauge that I described won't work.
they will work. they'll just be less accurate and a pain in the ass to
use.
>
>I fully intend to build them and will report back on how they turned out.
>Right after I install the DRO on my planer. Unfortunately it will be a few
>months.
>
>I'll build the jointer gauge pretty much as I described. But I'll be
>building a few different table saw gauges. One will be as I described. In
>addition, I want some way to get the two indicators to touch the fixed
>washer on the arbor, so that I can remove the blade and not worry about it
>being warped. I'm still thinking about how to do that.
simple geometry will tell you why this is a much less accurate
approach.
>
>
>
>"Ed Bennett" <[email protected]> wrote in message
>news:[email protected]...
>> Well "AL":
>>
>> Perhaps you should elaborate even more about your ideas! I'm thinking
>> that you should try them and then make an honest report back to the
>> group on how they worked. Maybe after you have actually tried these
>> things they won't seem like such great ideas.
>>
>> I guess you got my dander up because you specifically mention my
>> product (TS-Aligner Jr.) and how much it could be "improved" with this
>> idea of yours (multiple indicators). I think that it's enough of a
>> lesson if you are forced to try your own idea and report the results
>> back to the group - honestly. Then maybe you might think twice about
>> trying to fool members of this group into thinking you know anything
>> about machinery alignment or Metrology.
>>
>> Ed Bennett
>> [email protected]
>>
>> http://www.ts-aligner.com
>>
>> "AL" <[email protected]> wrote in message
>news:<FhJ0d.173062$Fg5.113792@attbi_s53>...
>> > Consider the gauge used to set jointer blades.
>>
>> <snip>
>>
>> > Now consider a modern version that holds two dial indicators spaced
>about 4"
>> > apart....
>>
>> <snip>
>>
>> > As for a table saw alignment tool like the TS Aligner Jr,...
>>
>> <snip>
>>
>> > Consider an improved version which has two indicators spaced about 8"
>apart
>>
>> <snip>
>
Again, I will explain a few of the problems. I will leave out the more
subtle ones for brevity. Assuming that you can get to the T slots, you now
angle your indicators to be able to reach them. By angling them, you have
reduced the sensitivity giving you the impression, in use, of being closer
to "dialed in" than you actually are. You then say to rig something up to
clamp your spindle, increasing complexity (and time to execute) of the
operation. Now, here you are with your 3 indicators (though, I can't see the
point of the middle one unless it is for impression value) mounted on a 6
inch bar (to cover the distance of a 6 inch machine vise) with a spindle
mount in the middle of the bar. You are going to hold this with one hand,
adjust it for zero and hold it from rotation within .0038 degrees while you
tighten it. Okay, lets assume that you do it the easy way. Clamp it in the
spindle, bring the indicators into contact with the T slots (you did
previously verify the accuracy of the T slots, didn't you?) and adjust the
dials for zero. Now, you lower the table or raise the spindle while
retracting the indicator spindles to keep them from snapping to the extremes
of their travel. BTW, how many hands do you have? You now bring the vise
under the spindle and bring the indicators into contact with the vise jaws.
After all this, you can now proceed to align your vise. You did verify that
the vise jaw didn't have a bump or dip in it, didn't you? How did you check?
How did you check the T slot? Can you guarantee that nothing moved in this
whole process? How can you verify that? There seems to be a lot of blind
faith going on here.
"AL" <[email protected]> wrote in message news:Ext2d.103639$3l3.44626@attbi_s03...
> The mill doesn't have to have a built in spindle lock. You just need some
> way to keep the spindle from turning as you tighten. You can clamp it
> yourself with a clamp or magnet.
>
> You don't have to use the sides of the table. You can use the side of a
> T-slot. The indicator stem doesn't have to parallel with the table
because
> you aren't taking an absolute measurement.
>
> "CW" <no adddress@spam free.com> wrote in message
> news:[email protected]...
> > This makes several assumptions (you know what an assumption is). It
> assumes
> > the spindle locks. Most don't. It assumes the sides of the table are
> > accessible. Not often the case. It assumes that the edges of the table
are
> > square and flat. Maybe, maybe not. There are finer details that I could
go
> > into but I won't in the interest of keeping this short.
> >
> > "AL" <[email protected]> wrote in message
> > news:rQ82d.185493$9d6.149008@attbi_s54...
> > > Aligning a mill vise with two indicators would take longer because the
> jig
> > > used to do the alignment was designed for one indicator (ie. clamp the
> > > indicator in the chuck and sweep the fixed jaw). Imagine a jig that
you
> > > clamp in the chuck/collet/holder that holds 3 indicators (all factory
> > > calibrated to read the same). The center indicator is centered with
the
> > > shaft in the chuck/collet/holder. All you have to do square the jig
> > against
> > > the table (ie. all 3 indicators read the same), clamp the spindle,
then
> > > adjust the vise so that the two outside indicators read the same as
the
> > > middle one. No more sweeping.
> > >
> > > "CW" <no adddress@spam free.com> wrote in message
> > > news:[email protected]...
> > > > Not at all. Dial indicators were developed by, and are used
> extensively
> > in
> > > > the metalworking industry. The reason for using a single gage is the
> > > > elimination of variables. The cost of indicators has never been a
> factor
> > > to
> > > > them. They have always been relatively cheap. For someone using an
> > > indicator
> > > > for alignment at home, two might seem easier. For me (machinist),
> > setting
> > > > two indicators to do a simple alignment (mill vise, or tablesaw
blade)
> > > would
> > > > increase the time to do the job.
> > > > "AL" <[email protected]> wrote in message
> > > news:n4a1d.183004$Fg5.53426@attbi_s53...
> > > > > My whole point is that people who design the gauges are stuck with
> an
> > > > > outdated way of thinking that says "dial indicators are expensive
so
> > my
> > > > > design will only use one".
> > > > >
> > > >
> > > >
> > >
> > >
> >
> >
>
>
Not at all. Dial indicators were developed by, and are used extensively in
the metalworking industry. The reason for using a single gage is the
elimination of variables. The cost of indicators has never been a factor to
them. They have always been relatively cheap. For someone using an indicator
for alignment at home, two might seem easier. For me (machinist), setting
two indicators to do a simple alignment (mill vise, or tablesaw blade) would
increase the time to do the job.
"AL" <[email protected]> wrote in message news:n4a1d.183004$Fg5.53426@attbi_s53...
> My whole point is that people who design the gauges are stuck with an
> outdated way of thinking that says "dial indicators are expensive so my
> design will only use one".
>
If you need a cable, have a look at this one:
http://www.littlemachineshop.com/products/product_view.php?ProductID=1990
"AL" <[email protected]> wrote in message news:z5t3d.73324$MQ5.32554@attbi_s52...
> I found it:
>
> http://www.shumatech.com/support/chinese_scales.htm#Digimatic%20Protocol
>
>
>
> "AL" <[email protected]> wrote in message news:Q3t3d.78643$D%.33927@attbi_s51...
> > A few months ago I found a web page that described the interface. I
just
> > looked but couldn't find it. Try searching rec.crafts.metalworking on
> > groups.google.com.
> >
> > A year ago, the vertical dro's were going for $50. Now they are $35. I
> > suspect in a few years they will be $5 and people will be installing
them
> on
> > their toilet seats.
> >
> >
> >
> > "Eric Anderson" <[email protected]> wrote in message
> > news:[email protected]...
> > > Absolutely unbelievable! I would never imagine that you can get these
> > > readouts for this kind of money. I would certainly get the readouts
> > > that are made for mounting on a tool for the $35 or so that they are
> > > asking for them. You can jog the number up or down slightly to bring
> > > it into the correct reading.
> > >
> > > By the way, where can I get the specs on the electrical interface? I
> > > called Harbor Freight on that, but even though they said they would
> > > get back to me, I don't think they will be able to find the info.
> > > Where would I look? The caliper is a Cen-tech. Tried to look them up
> > > with little success. If anyone knows who makes the readout or who in
> > > this country might know what the interface is, let me know.
> > >
> > > "AL" <[email protected]> wrote in message
> > news:<Hmb3d.217318$Fg5.99177@attbi_s53>...
> > > > Yes, clamping or gluing is the way to go. Drilling the caliper arms
> is
> > > > difficult.
> > > >
> > > > For around double the cost, you can get horizontal and vertical
dro's
> > which
> > > > look like Harbor Freight's digital calipers without the arms, but
with
> > > > mounting holes on both sides.
> > > >
> > > > Here is an example of a vertical one:
> > > >
> > > >
> >
>
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=12581&item=3840273611&rd=1
> > > >
> > > > and here is an example of a horizontal one:
> > > >
> > > >
> >
>
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=41939&item=3840604709&rd=1
> > > >
> > > > You can find better prices if you look for it.
> > > >
> > > > They also make very long ones, so you could put one on your table
saw
> > fence
> > > > if you wanted to.
> > > >
> > > > Some dro's and most digital calipers have serial port connectors
> > (intended
> > > > for statistical process control) so you could mount one inside your
> > table
> > > > saw trunnion and put a separate display somewhere else (for example
on
> > the
> > > > overhead guard if you have one). You could use it to display the
> height
> > of
> > > > the blade.
> > > >
> > > > You could also have one display the angle of blade, but that is a
bit
> > > > tricky.
> > > >
> >
> >
>
>
This is an interesting discussion with good points on both sides.
However, I would like to interrupt this presentation for a moment to
continue this thread started with the $16 digital caliper. This is an
unbelievable price since I paid $50 for a dial caliper from Mitutoyo
(sp?) in 1976 and thought it was a good deal.
I bought 2 of these calipers. One went on my drum sander to measure
its height and one I am going to use for its intended use. If I did
not already have a digital readout I bought for over $100 for my
planer, I would have CERTAINLY used one on it. Since the mechanical
scale on my Delta planer is nearly unusable, I would think that every
owner of one should buy one of these calipers for use on their planer.
By the way, I would recommend clamping the caliper arms somehow to the
planer. They are hardened and will ruin drill bits if you try to
drill through them for attachment. I was able to drill the holes, but
I ruined a couple of bits doing it.
Absolutely unbelievable! I would never imagine that you can get these
readouts for this kind of money. I would certainly get the readouts
that are made for mounting on a tool for the $35 or so that they are
asking for them. You can jog the number up or down slightly to bring
it into the correct reading.
By the way, where can I get the specs on the electrical interface? I
called Harbor Freight on that, but even though they said they would
get back to me, I don't think they will be able to find the info.
Where would I look? The caliper is a Cen-tech. Tried to look them up
with little success. If anyone knows who makes the readout or who in
this country might know what the interface is, let me know.
"AL" <[email protected]> wrote in message news:<Hmb3d.217318$Fg5.99177@attbi_s53>...
> Yes, clamping or gluing is the way to go. Drilling the caliper arms is
> difficult.
>
> For around double the cost, you can get horizontal and vertical dro's which
> look like Harbor Freight's digital calipers without the arms, but with
> mounting holes on both sides.
>
> Here is an example of a vertical one:
>
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=12581&item=3840273611&rd=1
>
> and here is an example of a horizontal one:
>
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=41939&item=3840604709&rd=1
>
> You can find better prices if you look for it.
>
> They also make very long ones, so you could put one on your table saw fence
> if you wanted to.
>
> Some dro's and most digital calipers have serial port connectors (intended
> for statistical process control) so you could mount one inside your table
> saw trunnion and put a separate display somewhere else (for example on the
> overhead guard if you have one). You could use it to display the height of
> the blade.
>
> You could also have one display the angle of blade, but that is a bit
> tricky.
>
Great Al. Thanks. A 3 axis display is shown here also. A little
pricey for my purposes. I am going to look for just a single external
display. So far I see that there are kits to make your own. Guess
that is an option. Really great source material. Thanks again.
"AL" <[email protected]> wrote in message news:<7at3d.13985$wV.7208@attbi_s54>...
> If you need a cable, have a look at this one:
>
> http://www.littlemachineshop.com/products/product_view.php?ProductID=1990
>
>
>
> "AL" <[email protected]> wrote in message news:z5t3d.73324$MQ5.32554@attbi_s52...
> > I found it:
> >
> > http://www.shumatech.com/support/chinese_scales.htm#Digimatic%20Protocol
> >
> >
> >
On 17 Sep 2004 14:22:06 -0700, [email protected] (Ed Bennett) wrote:
>Well, this is actually a bit different. Here there are two indicators
>measuring two different things (x movement and y movement) providing
>two different values (x and y) to locate a single object in two
>dimensions. The x and y readings are supposed to be completely
>independent of eachother (unless your lathe is a bit difficient).
my point exactly.
>
>There are times where a "comparator" of sorts will be constructed to
>provide differential measurements between an unknown and a fixed
>standard. Some of my electronic gaging equipment has inputs for this.
> Very complicated. Very expensive. Often a setup like this is used
>in the calibration of gage blocks. I tried to do it once and failed
>pretty miserably. I just don't have the facilities or capabilities to
>eliminate all the variables. You think it's easy until you try it!
>
>Thanks,
>
>Ed Bennett
>[email protected]
>http://www.ts-aligner.com
>
>[email protected] wrote in message news:<[email protected]>...
>
>> unless you're measuring travel in 2 directions simultaneously on the
>> cross slide on your metal lathe.
>>
>> which of course we wouldn't do here. it's not woodworking.....
Bridger, are you starting to think this guy is a puzzle maker? :)
<[email protected]> wrote in message
news:[email protected]...
> On 18 Sep 2004 15:44:41 -0700, [email protected] (Ed Bennett) wrote:
>
> >
> >> The table saw gauge is more complicated. I am assuming that a warped
blade
> >> is cupped such that you can turn it so that the curve is in the
vertical
> >> direction. I'm not sure how to describe this in words. Imagine
looking at
> >> the blade from the side and seeing something shaped like a left bracket
( .
> >
> >Yes, I know what you are talking about. It's called "bi-lateral
> >symmetry". You are assuming that there is an orientation of the blade
> >such that every point on one side of a centerline has a corresponding
> >point on the other side. You can probably find blades like this. You
> >might even own some. But, there is no guarantee that all blades will
> >exhibit bi-lateral symmetry.
>
>
>
> null axis of the warp......
>
>
> <GD&R>
As I said, you square it against the table by getting all 3 indicators to
read the same. To elaborate, you let all three stems touch the table, then
turn the chuck so that the three read the same. When this happens, the jig
is square to the table. Then clamp the spindle. It is a few seconds of
work.
"Jim Behning" <[email protected]> wrote in message
news:[email protected]...
> How do you square the 3 dial jig in the chuck? One indicator in a
> locked chuck and all you have to do is a sweep to check. Does it take
> hours to establish that the jig is square? What jig does it take to
> make sure the 3 indicator jig is square or parallel or plumb or choose
> your word?
>
> "AL" <[email protected]> wrote:
>
> >Aligning a mill vise with two indicators would take longer because the
jig
> >used to do the alignment was designed for one indicator (ie. clamp the
> >indicator in the chuck and sweep the fixed jaw). Imagine a jig that you
> >clamp in the chuck/collet/holder that holds 3 indicators (all factory
> >calibrated to read the same). The center indicator is centered with the
> >shaft in the chuck/collet/holder. All you have to do square the jig
against
> >the table (ie. all 3 indicators read the same), clamp the spindle, then
> >adjust the vise so that the two outside indicators read the same as the
> >middle one. No more sweeping.
> >
> >"CW" <no adddress@spam free.com> wrote in message
> >news:[email protected]...
> >> Not at all. Dial indicators were developed by, and are used extensively
in
> >> the metalworking industry. The reason for using a single gage is the
> >> elimination of variables. The cost of indicators has never been a
factor
> >to
> >> them. They have always been relatively cheap. For someone using an
> >indicator
> >> for alignment at home, two might seem easier. For me (machinist),
setting
> >> two indicators to do a simple alignment (mill vise, or tablesaw blade)
> >would
> >> increase the time to do the job.
> >> "AL" <[email protected]> wrote in message
> >news:n4a1d.183004$Fg5.53426@attbi_s53...
> >> > My whole point is that people who design the gauges are stuck with an
> >> > outdated way of thinking that says "dial indicators are expensive so
my
> >> > design will only use one".
> >> >
> >>
> >>
> >
>
:)
"Ed Bennett" <[email protected]> wrote in message
news:[email protected]...
> [email protected] wrote in message
news:<[email protected]>...
>
> > null axis of the warp......
>
> Yup! It's deja vu all over again!
The mill doesn't have to have a built in spindle lock. You just need some
way to keep the spindle from turning as you tighten. You can clamp it
yourself with a clamp or magnet.
You don't have to use the sides of the table. You can use the side of a
T-slot. The indicator stem doesn't have to parallel with the table because
you aren't taking an absolute measurement.
"CW" <no adddress@spam free.com> wrote in message
news:[email protected]...
> This makes several assumptions (you know what an assumption is). It
assumes
> the spindle locks. Most don't. It assumes the sides of the table are
> accessible. Not often the case. It assumes that the edges of the table are
> square and flat. Maybe, maybe not. There are finer details that I could go
> into but I won't in the interest of keeping this short.
>
> "AL" <[email protected]> wrote in message
> news:rQ82d.185493$9d6.149008@attbi_s54...
> > Aligning a mill vise with two indicators would take longer because the
jig
> > used to do the alignment was designed for one indicator (ie. clamp the
> > indicator in the chuck and sweep the fixed jaw). Imagine a jig that you
> > clamp in the chuck/collet/holder that holds 3 indicators (all factory
> > calibrated to read the same). The center indicator is centered with the
> > shaft in the chuck/collet/holder. All you have to do square the jig
> against
> > the table (ie. all 3 indicators read the same), clamp the spindle, then
> > adjust the vise so that the two outside indicators read the same as the
> > middle one. No more sweeping.
> >
> > "CW" <no adddress@spam free.com> wrote in message
> > news:[email protected]...
> > > Not at all. Dial indicators were developed by, and are used
extensively
> in
> > > the metalworking industry. The reason for using a single gage is the
> > > elimination of variables. The cost of indicators has never been a
factor
> > to
> > > them. They have always been relatively cheap. For someone using an
> > indicator
> > > for alignment at home, two might seem easier. For me (machinist),
> setting
> > > two indicators to do a simple alignment (mill vise, or tablesaw blade)
> > would
> > > increase the time to do the job.
> > > "AL" <[email protected]> wrote in message
> > news:n4a1d.183004$Fg5.53426@attbi_s53...
> > > > My whole point is that people who design the gauges are stuck with
an
> > > > outdated way of thinking that says "dial indicators are expensive so
> my
> > > > design will only use one".
> > > >
> > >
> > >
> >
> >
>
>
Consider the gauge used to set jointer blades. To see an example, search
Woodcraft's web page for item 126979. It is essentially an iron square that
holds one dial indicator above the blade. The design dates from a time when
dial indicators were very expensive and so the gauge was designed to use
only one indicator. You slide it back and forth repetitively, and wiggle
the blade until you get the same reading at different positions.
Now consider a modern version that holds two dial indicators spaced about 4"
apart. You set the square on the jointer's outfeed bed such that both
indicator stems touch the bed. Move the arrows (ie. most dial indicators
have 2 moveable arrows around the outside) to mark the readings (both
indicators do not need to read the same). You've just zeroed out both
indicators. Now slide the square so that the stems touch the blade, and
adjust the blade so that the indicator needles touch the arrows (ie. the
zero position that you previously established). You don't have to slide the
gauge back and forth. And you only need minimal adjustment of the blade.
As for a table saw alignment tool like the TS Aligner Jr, first you slide it
back and forth and adjust the bearings to take up slop in the miter gauge
slot. Then you slide it back and forth along the blade (turning the blade
at the same time). You have to do this because you only have one dial
indicator.
Consider an improved version which has two indicators spaced about 8" apart
which has been factory adjusted so that both indicators read the same. You
put it in the miter gauge so that both indicators are touching the blade.
Then you turn an eccentric bolt which locks the gauge in place. No more
sliding back and forth. Now you turn the blade several revolutions by hand
and watch both indicators as you turn. If the blade is warped, the needles
are going to move a lot, and you want to stop at a point where the needles
aren't moving very much (ie. you've moved the warp into the vertical axis).
If the blade isn't warped, the needles won't move much and you can stop
anywhere. Now get out the hammer and screwdriver and adjust the table so
that both indicators read the same. If you don't want a factory adjusted
gauge, you can use a machinist's square to zero out the indicators.
"Jay Pique" <[email protected]> wrote in message
news:[email protected]...
> "AL" <[email protected]> wrote:
>
> > Many tools (such as the TS Aligner Jr, and numerous
> >height gauges used to set jointer/shaper blades) use outdated designs
which
> >assume only one Starrett (or Starrett like) indicator at $100+ (ie. you
only
> >have one). But these tools could do a far better and quicker job if they
> >were designed to use 2 or 3 indicators.
>
> I'm not very well versed in the nuances of alignment and set up jigs
> for machinery, but I'm very intrigued by your line of thinking. Could
> you elaborate a little on how you would envision a multiple gauge to
> work, and why it would be better and quicker? Thanks.
>
> JP
> ********************
> Now you've got me thinking....
Did I miss something?
"Ed Bennett" <[email protected]> wrote in message
news:[email protected]...
> [email protected] wrote in message
news:<[email protected]>...
>
> > null axis of the warp......
>
> Yup! It's deja vu all over again!
"AL" <[email protected]> wrote in message news:W7P2d.62468$MQ5.53211@attbi_s52...
>
> I concede that either the T slot or the side/edge of the table needs to be
> straight and parallel to the direction of travel for this to work.
> Otherwise it won't.
So, prior to setup, you calibrate the surface you are going to use for
calibration. Are you going to use another one of your rigs that needs to be
calibrated before you calibrate the calibration surface?
>
> On my mill, I estimate that the indicators would need to be tilted 2
degrees
> to access the T slot. Would a factor of cosine(2) or 0.99939 really
reduce
> the sensitivity of the indicator?
More like 30 degrees in a 5/8 T slot. In addition to the measurement error
that would be introduced, you now have put the indicator bearings in a bind,
further reducing sensitivity.
>
> I don't see why more than two hands would be required. Mount vise on
table.
> Mount gauge in collet/holder/chuck. Raise knee, lower spindle, move X and
> Y. Up to this point, you would have to do all of this regardless of
whether
> you are using one indicator, or more than one. When doing this, stop when
> the indicators touch the T slot or edge of table near the vise. Square
the
> gauge by turning spindle with one finger (see other post). No need to
dial
> for zero. Both gauges just need to read the same. Clamp the spindle.
> Raise the spindle slightly, and move the X axis slightly so that the
> indicators touch the vise jaw. Now adjust the vise so that both
indicators
> read the same (they don't have to read zero).
You are going to rotate that spindle .0001 or so and then expect that it
will maintain position while you clamp it... Right.
>
> You wouldn't move the vise so that the indicator points fall into (for
> example), the vise jaw mounting holes. If the vise jaw isn't straight,
> you'll have problems regardless of how many indicators you're using.
So, now you are just going to go on blind faith that the vise jaws are true.
The time to find this out is before you scrap a part. With your rig, you'd
never know. This is kind of like measuring the height of a wall with a 6
inch scale or, something many here will really relate to, using 4 different
tape measures on the same job. It might work but chances are it won't and
you can't be certain until you have produced scrap.
>
>
>
The gages sold by Oneway and Powermatic use flat disk shaped points. I will
be trying several different shapes to see what works best. The rules be
d*mned. I also have the Fundamentals of Dimensional Metrology and think it
is very good.
"Ed Bennett" <[email protected]> wrote in message
news:[email protected]...
> I've purchased a number of these cheap angle plates for fixturing in
> the shop. They are pretty handy but don't expect them to be very
> accurate. Don't be surprised if they rock on a flat surface.
>
> The proper choice of indicator point is Metrology kindergarden. A
> flat stylus should only be used on a round surface. A round stylus
> should only be used on a flat surface. A knife edge is basically a
> flat surface (flat in one dimension anyway). To obtain reliable and
> repeatable results, a round stylus is called for.
>
> "Flat contact points have an important role but can be a serious cause
> of error when improperly used" "Fundamentals of Dimensional Metrology"
> by Ted Busch, 2nd Edition p.256, (c) 1989 Delmar Publishers Inc.
>
> This is a great book by the way. A "must read" for anyone interested
> in designing their own alignment and measurement fixturing. It can
> still be found on Amazon for about $3.00. The latest edition will set
> you back about $85.
>
> Ed Bennett
> [email protected]
>
> http://www.ts-aligner.com
>
>
> "AL" <[email protected]> wrote in message
news:<b8b3d.69057$MQ5.52997@attbi_s52>...
> > The angle plates I'm considering are in the $5 to $10 range--imported to
> > match my imported indicators. I realize the disk shaped points require
the
> > indicators to be perpendicular. I just don't think it will be that hard
to
> > do. But I will experiment with both types of points.
> >
Yes, clamping or gluing is the way to go. Drilling the caliper arms is
difficult.
For around double the cost, you can get horizontal and vertical dro's which
look like Harbor Freight's digital calipers without the arms, but with
mounting holes on both sides.
Here is an example of a vertical one:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=12581&item=3840273611&rd=1
and here is an example of a horizontal one:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=41939&item=3840604709&rd=1
You can find better prices if you look for it.
They also make very long ones, so you could put one on your table saw fence
if you wanted to.
Some dro's and most digital calipers have serial port connectors (intended
for statistical process control) so you could mount one inside your table
saw trunnion and put a separate display somewhere else (for example on the
overhead guard if you have one). You could use it to display the height of
the blade.
You could also have one display the angle of blade, but that is a bit
tricky.
"Eric Anderson" <[email protected]> wrote in message
news:[email protected]...
> This is an interesting discussion with good points on both sides.
> However, I would like to interrupt this presentation for a moment to
> continue this thread started with the $16 digital caliper. This is an
> unbelievable price since I paid $50 for a dial caliper from Mitutoyo
> (sp?) in 1976 and thought it was a good deal.
>
> I bought 2 of these calipers. One went on my drum sander to measure
> its height and one I am going to use for its intended use. If I did
> not already have a digital readout I bought for over $100 for my
> planer, I would have CERTAINLY used one on it. Since the mechanical
> scale on my Delta planer is nearly unusable, I would think that every
> owner of one should buy one of these calipers for use on their planer.
>
> By the way, I would recommend clamping the caliper arms somehow to the
> planer. They are hardened and will ruin drill bits if you try to
> drill through them for attachment. I was able to drill the holes, but
> I ruined a couple of bits doing it.
This makes several assumptions (you know what an assumption is). It assumes
the spindle locks. Most don't. It assumes the sides of the table are
accessible. Not often the case. It assumes that the edges of the table are
square and flat. Maybe, maybe not. There are finer details that I could go
into but I won't in the interest of keeping this short.
"AL" <[email protected]> wrote in message
news:rQ82d.185493$9d6.149008@attbi_s54...
> Aligning a mill vise with two indicators would take longer because the jig
> used to do the alignment was designed for one indicator (ie. clamp the
> indicator in the chuck and sweep the fixed jaw). Imagine a jig that you
> clamp in the chuck/collet/holder that holds 3 indicators (all factory
> calibrated to read the same). The center indicator is centered with the
> shaft in the chuck/collet/holder. All you have to do square the jig
against
> the table (ie. all 3 indicators read the same), clamp the spindle, then
> adjust the vise so that the two outside indicators read the same as the
> middle one. No more sweeping.
>
> "CW" <no adddress@spam free.com> wrote in message
> news:[email protected]...
> > Not at all. Dial indicators were developed by, and are used extensively
in
> > the metalworking industry. The reason for using a single gage is the
> > elimination of variables. The cost of indicators has never been a factor
> to
> > them. They have always been relatively cheap. For someone using an
> indicator
> > for alignment at home, two might seem easier. For me (machinist),
setting
> > two indicators to do a simple alignment (mill vise, or tablesaw blade)
> would
> > increase the time to do the job.
> > "AL" <[email protected]> wrote in message
> news:n4a1d.183004$Fg5.53426@attbi_s53...
> > > My whole point is that people who design the gauges are stuck with an
> > > outdated way of thinking that says "dial indicators are expensive so
my
> > > design will only use one".
> > >
> >
> >
>
>
What you call magic, I call child's play.
The three indicators need to read the same to work. Adjusting them at the
factory is child's play. Merely a setscrew that allows the indicator to
slide back and forth.
If you want to do your own calibration, you merely need to use a machinists
square. One leg against the indicator stems, another leg against the edge
of the holder (that has been machined square).
I use indicators all the time. I don't handicap myself by doing things the
traditional way.
<[email protected]> wrote in message
news:[email protected]...
> On Thu, 16 Sep 2004 11:56:21 GMT, Jim Behning
> <[email protected]> wrote:
>
> >How do you square the 3 dial jig in the chuck? One indicator in a
> >locked chuck and all you have to do is a sweep to check. Does it take
> >hours to establish that the jig is square? What jig does it take to
> >make sure the 3 indicator jig is square or parallel or plumb or choose
> >your word?
>
>
> he's using magic- "factory calibrated to read the same".
>
> I don't think he's used indicators much.
>
>
>
>
>
>
>
> >
> >"AL" <[email protected]> wrote:
> >
> >>Aligning a mill vise with two indicators would take longer because the
jig
> >>used to do the alignment was designed for one indicator (ie. clamp the
> >>indicator in the chuck and sweep the fixed jaw). Imagine a jig that you
> >>clamp in the chuck/collet/holder that holds 3 indicators (all factory
> >>calibrated to read the same). The center indicator is centered with the
> >>shaft in the chuck/collet/holder. All you have to do square the jig
against
> >>the table (ie. all 3 indicators read the same), clamp the spindle, then
> >>adjust the vise so that the two outside indicators read the same as the
> >>middle one. No more sweeping.
> >>
> >>"CW" <no adddress@spam free.com> wrote in message
> >>news:[email protected]...
> >>> Not at all. Dial indicators were developed by, and are used
extensively in
> >>> the metalworking industry. The reason for using a single gage is the
> >>> elimination of variables. The cost of indicators has never been a
factor
> >>to
> >>> them. They have always been relatively cheap. For someone using an
> >>indicator
> >>> for alignment at home, two might seem easier. For me (machinist),
setting
> >>> two indicators to do a simple alignment (mill vise, or tablesaw blade)
> >>would
> >>> increase the time to do the job.
> >>> "AL" <[email protected]> wrote in message
> >>news:n4a1d.183004$Fg5.53426@attbi_s53...
> >>> > My whole point is that people who design the gauges are stuck with
an
> >>> > outdated way of thinking that says "dial indicators are expensive so
my
> >>> > design will only use one".
> >>> >
> >>>
> >>>
> >>
>
Regarding the jointer gauge, what I plan to do is get an angle plate of the
right size, drill and tap two holes on the sides and then mount two
indicators. Both indicators first touch the outfeed table. The dials get
zeroed. Then the gauge is moved forward to touch the knife edge. Because
the goal is to get the dials to read zero again (ie. I'm not measuring a
linear distance. Cosine of the angle multiplied by zero.), I don't see any
effect if either indicator were slightly tilted (even thought it will be
very easy to be sure they are not). The angle plate is identical on both
sides so one side wouldn't flex more than the other. The spring tension on
the indicators may not be the same, but won't have enough force to either
lift the angle plate, or lower the knife. The stylus points won't matter
because the part of the point that initially touched the outfeed table, will
be touching the edge of the knife. However, I may use disk-shaped points to
make it easier to put the point on the knife.
The table saw gauge is more complicated. I am assuming that a warped blade
is cupped such that you can turn it so that the curve is in the vertical
direction. I'm not sure how to describe this in words. Imagine looking at
the blade from the side and seeing something shaped like a left bracket ( .
If the warpage is more like a ripple than a cup, then what I am proposing
won't work. I'll have to measure a few of my blades and see just what they
look like.
The only reason I mentioned your product by name was that everyone knows
what I'm talking about when they hear it. If there was a popular brand of
jointer gauge like the one I was talking about (Oneway and Powermatic make
one--I've seen several more), I would have used that name. In retrospect,
it was a bad idea.
"Ed Bennett" <[email protected]> wrote in message
news:[email protected]...
> "AL":
>
> OK, I guess you are asking me to help you get started thinking about
> the problems with your ideas. I don't mind doing this, as you've
> pretty much admitted in the request that you haven't tried your ideas
> (or even given much thought to their feasibility).
>
> Whenever you have one measurement device on one fixture you have a
> stable reference. All subsequent measurements using this same exact
> setup will be relative to this same exact reference. All the
> individual variables which make up that reference will be included
> identically in every measurement so that their relative effect from
> measurement to measurement is completely nullified. If you introduce
> a second measurement device and attempt to make the same measurements
> in a repeatable manner then you create a second reference. All of the
> variables making up both references become significant. Each variable
> must be addressed individually and it's contribution to the results
> quantified and/or eliminated. If this is not done, then you will
> never know if the readings accurately represent the objects being
> measured or the effects of these uncontrolled variables.
>
> To put it another way, it might seem rather inconvenient to use one
> measurement device and one fixture to do multiple measurements, but it
> is an effortless method which guarantees that each measurement is done
> with an identical setup. No external variables will influence the
> results. If two measurements come out differently, it's because the
> objects being measured are different. If two measurements come out
> the same, it's because the two objects being measured are identical.
>
> For example, in your jointer knife alignment idea, a rather elaborate
> calibration procedure would be necessary to ensure that the two dial
> indicators were providing the same readings for any given measurement.
> Just because they read the same for one measurement pair (say, the
> top of the outfeed table) doesn't mean that they actually provide the
> same measurements. What if one indicator isn't tilted at the exact
> same angle as the other? What if one side of the fixture flexes more
> than another? What if the measurement force of one indicator is more
> than the other? What if the two stylus points are slightly different
> sizes or shapes?
>
> Yes, it is possible to create a fixture, choose indicators, and
> account for all the possible variables which can significantly alter
> the results so that two identical measurements can be performed at the
> same time using two indicators. But why would you ever want to go to
> all this trouble when you could just use one indicator on one fixture
> to make two measurements?
>
> Also, I just can't imagine trying to manage two indicator styli on a
> knife edge at the same time. You may decide that it's good enough to
> just worry about one at a time but then where's the advantage of
> having two indicators?
>
> All of the above applies to your tablesaw alignment example too. In
> addition, you have assumed that blade warp is always bi-lateral and
> symmetrical. Sorry, that's a bad assumption. It's also not valid to
> assume that the arbor and flange (what you call the "fixed washer on
> the arbor") have no runout. You can obtain different readings on your
> two dial indicators and not be able to discern if they are due to
> misalignment, runout, warp, or one of the variables mentioned above.
> If you obtain identical readings on your two dial indicators, there is
> no assurance that proper alignment has been obtained. This is truely
> a case in which no amount of "factory calibration" will help. It's a
> setup which voilates all the applicable Metrological rules.
>
> An alignment tool must be able to perform it's task without being
> adversely affected by these uncontrolled variables. Making two
> measurements with a single indicator setup using a fixed reference
> (the dot on the blade) is completely immune to all of the variables
> mentioned. When the two readings are the same then the saw is
> definitely aligned beyond any reasonable doubt.
>
> This is just the tip of the iceberg. These are just conceptual level
> reasons why your idea is impractical. There are lots of other things
> to consider which you'll discover when you attempt to build your
> prototypes. I would be more than happy to discuss these things and
> I'm sure that there are others in the group who would be interested in
> reading along. But, we must agree not to name specific products and
> identify them as "inferior" when we really don't understand the the
> most basic principles of the topic at hand. Agreed?
>
> Thanks,
>
> Ed Bennett
> [email protected]
> http://www.ts-aligner.com
>
> "AL" <[email protected]> wrote in message
news:<SJt2d.314009$8_6.193390@attbi_s04>...
> > Ed,
> >
> > In your two posts, all I see is a personal attack. Fair enough because
I
> > insulted your product. However I don't see anything that says why the
> > jointer and table saw gauge that I described won't work.
> >
> > I fully intend to build them and will report back on how they turned
out.
> > Right after I install the DRO on my planer. Unfortunately it will be a
few
> > months.
> >
> > I'll build the jointer gauge pretty much as I described. But I'll be
> > building a few different table saw gauges. One will be as I described.
In
> > addition, I want some way to get the two indicators to touch the fixed
> > washer on the arbor, so that I can remove the blade and not worry about
it
> > being warped. I'm still thinking about how to do that.
As I said before. Your setup introduces more variables and takes longer to
do the job as you have to calibrate.
"AL" <[email protected]> wrote in message
news:MRk2d.445194$%_6.217615@attbi_s01...
> What you call magic, I call child's play.
>
> The three indicators need to read the same to work. Adjusting them at the
> factory is child's play. Merely a setscrew that allows the indicator to
> slide back and forth.
>
> If you want to do your own calibration, you merely need to use a
machinists
> square. One leg against the indicator stems, another leg against the edge
> of the holder (that has been machined square).
>
> I use indicators all the time. I don't handicap myself by doing things
the
> traditional way.
>
>
Have you considered attaching one of these to your planer?
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=12581&item=3839370322&rd=1
I just received mine and will be attaching it to my Ridgid planer in a few
weeks (I have a few other projects to finish first). I'll post after I
install it.
"Mark & Juanita" <[email protected]> wrote in message
news:[email protected]...
> On Sat, 11 Sep 2004 00:11:37 GMT, "patrick conroy"
> <[email protected]> wrote:
>
> >The Starrett Buy American thread reminded me to chime in with a personal
> >experience on:
> >http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=47257
> >
> >I've had mine for two years now - it's great! Used enough to be on
Battery
> >#3.
> >While I don't have a machinist's reference point to calibrate it to -
I've
> >measured a number of off the shelf items - drill bits, chisels, screws,
etc.
> >This unit is within a few thousands of what you'd assume it would report.
As
> >for accuracy, it again seems to put up data repeatable to a thou or so...
> >
> >If all the units are as nice as mine, I think it's a great buy at $16.
> >
>
>
> I've been thinking about attaching one to my planer for quite some
time,
> but haven't pried open the wallet to buy one to drill holes in. This may
> be the ticket if I can concoct an attachment method that doesn't look
> totally jury-rigged.
A few months ago I found a web page that described the interface. I just
looked but couldn't find it. Try searching rec.crafts.metalworking on
groups.google.com.
A year ago, the vertical dro's were going for $50. Now they are $35. I
suspect in a few years they will be $5 and people will be installing them on
their toilet seats.
"Eric Anderson" <[email protected]> wrote in message
news:[email protected]...
> Absolutely unbelievable! I would never imagine that you can get these
> readouts for this kind of money. I would certainly get the readouts
> that are made for mounting on a tool for the $35 or so that they are
> asking for them. You can jog the number up or down slightly to bring
> it into the correct reading.
>
> By the way, where can I get the specs on the electrical interface? I
> called Harbor Freight on that, but even though they said they would
> get back to me, I don't think they will be able to find the info.
> Where would I look? The caliper is a Cen-tech. Tried to look them up
> with little success. If anyone knows who makes the readout or who in
> this country might know what the interface is, let me know.
>
> "AL" <[email protected]> wrote in message
news:<Hmb3d.217318$Fg5.99177@attbi_s53>...
> > Yes, clamping or gluing is the way to go. Drilling the caliper arms is
> > difficult.
> >
> > For around double the cost, you can get horizontal and vertical dro's
which
> > look like Harbor Freight's digital calipers without the arms, but with
> > mounting holes on both sides.
> >
> > Here is an example of a vertical one:
> >
> >
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=12581&item=3840273611&rd=1
> >
> > and here is an example of a horizontal one:
> >
> >
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=41939&item=3840604709&rd=1
> >
> > You can find better prices if you look for it.
> >
> > They also make very long ones, so you could put one on your table saw
fence
> > if you wanted to.
> >
> > Some dro's and most digital calipers have serial port connectors
(intended
> > for statistical process control) so you could mount one inside your
table
> > saw trunnion and put a separate display somewhere else (for example on
the
> > overhead guard if you have one). You could use it to display the height
of
> > the blade.
> >
> > You could also have one display the angle of blade, but that is a bit
> > tricky.
> >
Ed,
In your two posts, all I see is a personal attack. Fair enough because I
insulted your product. However I don't see anything that says why the
jointer and table saw gauge that I described won't work.
I fully intend to build them and will report back on how they turned out.
Right after I install the DRO on my planer. Unfortunately it will be a few
months.
I'll build the jointer gauge pretty much as I described. But I'll be
building a few different table saw gauges. One will be as I described. In
addition, I want some way to get the two indicators to touch the fixed
washer on the arbor, so that I can remove the blade and not worry about it
being warped. I'm still thinking about how to do that.
"Ed Bennett" <[email protected]> wrote in message
news:[email protected]...
> Well "AL":
>
> Perhaps you should elaborate even more about your ideas! I'm thinking
> that you should try them and then make an honest report back to the
> group on how they worked. Maybe after you have actually tried these
> things they won't seem like such great ideas.
>
> I guess you got my dander up because you specifically mention my
> product (TS-Aligner Jr.) and how much it could be "improved" with this
> idea of yours (multiple indicators). I think that it's enough of a
> lesson if you are forced to try your own idea and report the results
> back to the group - honestly. Then maybe you might think twice about
> trying to fool members of this group into thinking you know anything
> about machinery alignment or Metrology.
>
> Ed Bennett
> [email protected]
>
> http://www.ts-aligner.com
>
> "AL" <[email protected]> wrote in message
news:<FhJ0d.173062$Fg5.113792@attbi_s53>...
> > Consider the gauge used to set jointer blades.
>
> <snip>
>
> > Now consider a modern version that holds two dial indicators spaced
about 4"
> > apart....
>
> <snip>
>
> > As for a table saw alignment tool like the TS Aligner Jr,...
>
> <snip>
>
> > Consider an improved version which has two indicators spaced about 8"
apart
>
> <snip>
Precision machining has been my job for almost 18 years. I have a pretty
good idea what works and what doesn't.
"AL" <[email protected]> wrote in message news:oBt2d.103662$3l3.14885@attbi_s03...
> I agree it introduces more variables, but I don't think it will take
longer
> than sweeping the vise back and forth.
>
> "CW" <no adddress@spam free.com> wrote in message
> news:[email protected]...
> > As I said before. Your setup introduces more variables and takes longer
to
> > do the job as you have to calibrate.
> > "AL" <[email protected]> wrote in message
> > news:MRk2d.445194$%_6.217615@attbi_s01...
> > > What you call magic, I call child's play.
> > >
> > > The three indicators need to read the same to work. Adjusting them at
> the
> > > factory is child's play. Merely a setscrew that allows the indicator
to
> > > slide back and forth.
> > >
> > > If you want to do your own calibration, you merely need to use a
> > machinists
> > > square. One leg against the indicator stems, another leg against the
> edge
> > > of the holder (that has been machined square).
> > >
> > > I use indicators all the time. I don't handicap myself by doing
things
> > the
> > > traditional way.
> > >
> > >
> >
> >
>
>
I was starting to type out why I needed the middle indicator, but I couldn't
think of anything. I'm not sure why I initially said three. Two is enough
for what I'm proposing.
I concede that either the T slot or the side/edge of the table needs to be
straight and parallel to the direction of travel for this to work.
Otherwise it won't.
On my mill, I estimate that the indicators would need to be tilted 2 degrees
to access the T slot. Would a factor of cosine(2) or 0.99939 really reduce
the sensitivity of the indicator?
I don't see why more than two hands would be required. Mount vise on table.
Mount gauge in collet/holder/chuck. Raise knee, lower spindle, move X and
Y. Up to this point, you would have to do all of this regardless of whether
you are using one indicator, or more than one. When doing this, stop when
the indicators touch the T slot or edge of table near the vise. Square the
gauge by turning spindle with one finger (see other post). No need to dial
for zero. Both gauges just need to read the same. Clamp the spindle.
Raise the spindle slightly, and move the X axis slightly so that the
indicators touch the vise jaw. Now adjust the vise so that both indicators
read the same (they don't have to read zero).
You wouldn't move the vise so that the indicator points fall into (for
example), the vise jaw mounting holes. If the vise jaw isn't straight,
you'll have problems regardless of how many indicators you're using.
"CW" <no adddress@spam free.com> wrote in message
news:[email protected]...
> Again, I will explain a few of the problems. I will leave out the more
> subtle ones for brevity. Assuming that you can get to the T slots, you now
> angle your indicators to be able to reach them. By angling them, you have
> reduced the sensitivity giving you the impression, in use, of being closer
> to "dialed in" than you actually are. You then say to rig something up to
> clamp your spindle, increasing complexity (and time to execute) of the
> operation. Now, here you are with your 3 indicators (though, I can't see
the
> point of the middle one unless it is for impression value) mounted on a 6
> inch bar (to cover the distance of a 6 inch machine vise) with a spindle
> mount in the middle of the bar. You are going to hold this with one hand,
> adjust it for zero and hold it from rotation within .0038 degrees while
you
> tighten it. Okay, lets assume that you do it the easy way. Clamp it in the
> spindle, bring the indicators into contact with the T slots (you did
> previously verify the accuracy of the T slots, didn't you?) and adjust the
> dials for zero. Now, you lower the table or raise the spindle while
> retracting the indicator spindles to keep them from snapping to the
extremes
> of their travel. BTW, how many hands do you have? You now bring the vise
> under the spindle and bring the indicators into contact with the vise
jaws.
> After all this, you can now proceed to align your vise. You did verify
that
> the vise jaw didn't have a bump or dip in it, didn't you? How did you
check?
> How did you check the T slot? Can you guarantee that nothing moved in this
> whole process? How can you verify that? There seems to be a lot of blind
> faith going on here.
>
> "AL" <[email protected]> wrote in message
news:Ext2d.103639$3l3.44626@attbi_s03...
> > The mill doesn't have to have a built in spindle lock. You just need
some
> > way to keep the spindle from turning as you tighten. You can clamp it
> > yourself with a clamp or magnet.
> >
> > You don't have to use the sides of the table. You can use the side of a
> > T-slot. The indicator stem doesn't have to parallel with the table
> because
> > you aren't taking an absolute measurement.
> >
> > "CW" <no adddress@spam free.com> wrote in message
> > news:[email protected]...
> > > This makes several assumptions (you know what an assumption is). It
> > assumes
> > > the spindle locks. Most don't. It assumes the sides of the table are
> > > accessible. Not often the case. It assumes that the edges of the table
> are
> > > square and flat. Maybe, maybe not. There are finer details that I
could
> go
> > > into but I won't in the interest of keeping this short.
> > >
> > > "AL" <[email protected]> wrote in message
> > > news:rQ82d.185493$9d6.149008@attbi_s54...
> > > > Aligning a mill vise with two indicators would take longer because
the
> > jig
> > > > used to do the alignment was designed for one indicator (ie. clamp
the
> > > > indicator in the chuck and sweep the fixed jaw). Imagine a jig that
> you
> > > > clamp in the chuck/collet/holder that holds 3 indicators (all
factory
> > > > calibrated to read the same). The center indicator is centered with
> the
> > > > shaft in the chuck/collet/holder. All you have to do square the jig
> > > against
> > > > the table (ie. all 3 indicators read the same), clamp the spindle,
> then
> > > > adjust the vise so that the two outside indicators read the same as
> the
> > > > middle one. No more sweeping.
> > > >
> > > > "CW" <no adddress@spam free.com> wrote in message
> > > > news:[email protected]...
> > > > > Not at all. Dial indicators were developed by, and are used
> > extensively
> > > in
> > > > > the metalworking industry. The reason for using a single gage is
the
> > > > > elimination of variables. The cost of indicators has never been a
> > factor
> > > > to
> > > > > them. They have always been relatively cheap. For someone using an
> > > > indicator
> > > > > for alignment at home, two might seem easier. For me (machinist),
> > > setting
> > > > > two indicators to do a simple alignment (mill vise, or tablesaw
> blade)
> > > > would
> > > > > increase the time to do the job.
> > > > > "AL" <[email protected]> wrote in message
> > > > news:n4a1d.183004$Fg5.53426@attbi_s53...
> > > > > > My whole point is that people who design the gauges are stuck
with
> > an
> > > > > > outdated way of thinking that says "dial indicators are
expensive
> so
> > > my
> > > > > > design will only use one".
> > > > > >
> > > > >
> > > > >
> > > >
> > > >
> > >
> > >
> >
> >
>
>
Mark & Juanita <[email protected]> wrote in
news:[email protected]:
<snip>
>
> I've been thinking about attaching one to my planer for quite some
> time,
> but haven't pried open the wallet to buy one to drill holes in. This
> may be the ticket if I can concoct an attachment method that doesn't
> look totally jury-rigged.
>
While you're puzzling on that problem, see if you can add in some sort of
solution flexibility for use, having inserted a bed extension. The kind
one uses for thinner stock, and to reduce snipe.
Preferably something that doesn't require me to do addition including
measurements in 32nds of an inch.
If you get the time. And are interested. And don't mind sharing. For
free.
I don't want much, do I? ;-)
Patriarch
Mark & Juanita <[email protected]> wrote in
news:[email protected]:
<snip>
>
> Thanks -- definitely a better solution than jury-rigging a caliper
>
Ageed.
Patriarch
Is it right tilt or left tilt? What kind does Nahm use?? ;-)
Mark L.
Unisaw A100 wrote:
> AArDvarK wrote:
>
>>Vernier's don't take batteries. They are not digital.
>
>
>
> So what size cord should they have?
>
> Would converting it to 220 give it more horsepower?
>
> I found one that's three phase. Do I need a rotary
> convertor or would static be OK?
>
> UA100
The angle plates I'm considering are in the $5 to $10 range--imported to
match my imported indicators. I realize the disk shaped points require the
indicators to be perpendicular. I just don't think it will be that hard to
do. But I will experiment with both types of points.
"Ed Bennett" <[email protected]> wrote in message
news:[email protected]...
> Hello again AL,
>
> As I said, it is possible to create a fixture to do what you want (on
> the jointer at least) but the task is not easy and accurate results
> aren't going to come cheap.
>
> "AL" <[email protected]> wrote in message
news:<NTO2d.62407$MQ5.26300@attbi_s52>...
> > Regarding the jointer gauge, what I plan to do is get an angle plate of
the
> > right size, drill and tap two holes on the sides and then mount two
> > indicators.
>
> Not bad. So, as you can see already, the fixturing (the angle plate
> in this case) will be the most expensive element of your design. For
> the most part, this is always true. The first logical question
> involves choosing the "right size" for your angle plate. Since the
> indicators will be attached to the sides, they are mounted in fixed
> locations which are determined by the size of the angle plate. One
> size won't fit all jointers. So, several models would be needed.
> It's not a very attractive solution for someone with more than one
> jointer (or someone planning to upgrade to a larger model someday).
>
> It's also a "one function" solution. It is designed for jointers only
> (just imagine trying to calibrate this for planers). Expensive,
> single function products are not a very attractive to prospective
> customers.
>
> > Both indicators first touch the outfeed table. The dials get
> > zeroed.
>
> Unfortunately, this doesn't guarantee that the two indicators provide
> the same measurements. If you are sure that your outfeed table is
> sufficiently flat then this works. If you are not sure, then it's
> equivalent to calibrating your instrument using an unknown standard.
> A good calibration instrument needs to be immune to imperfections in
> the machinery. It needs to work for everyone who follows the
> instructions properly. If good alignment is possible, then the
> instrument should facilitate it. If good alignment is not possible,
> then the instrument should not fool you into thinking you have good
> alignment.
>
> > Then the gauge is moved forward to touch the knife edge. Because
> > the goal is to get the dials to read zero again (ie. I'm not measuring a
> > linear distance. Cosine of the angle multiplied by zero.), I don't see
any
> > effect if either indicator were slightly tilted (even thought it will be
> > very easy to be sure they are not).
>
> Just give it a try and let us know how you make out. It's not a
> matter of the effect that tilt will have on one indicator's ability to
> provide absolute linear measurements. Remember, you're trying to get
> two indicators to read the same thing when they are measuring the same
> thing. Exaggerate the possibilities in your mind or just give it a
> try and see what happens. If the difference in readings is less than
> 0.001", can you be sure that the difference in the objects being
> measured is less than 0.001"? You can always check the accuracy of
> your results using the single indicator setup (which is, in fact,
> quite immune to tilt so long as you use a spherical indicator point).
>
> I also think you're going to have a lot of difficulty ensuring that
> the dial indicators are aligned (have the same tilt).
>
> > The angle plate is identical on both
> > sides so one side wouldn't flex more than the other. The spring tension
on
> > the indicators may not be the same, but won't have enough force to
either
> > lift the angle plate, or lower the knife.
>
> The fixturing is definitely rigid enough and quite heavy (though not
> very adjustable). While two indicators may respond differently to
> different measurement pressures you probably don't have to worry about
> this too much.
>
> > The stylus points won't matter
> > because the part of the point that initially touched the outfeed table,
will
> > be touching the edge of the knife. However, I may use disk-shaped
points to
> > make it easier to put the point on the knife.
>
> Actually, the stylus points make a huge difference - especially if you
> plan to use flat rather than spherical indicator points (a very common
> mistake). Imagine the effects of indicator tilt when using a flat
> stylus. If there is any tilt in either direction, then the reading
> will vary significantly depending on where the knife contacts the
> surface of the stylus. How will you determine if a difference in
> readings is the result of misalignment or tilt related positioning of
> the knife edge? Can you really ensure that the indicator point
> touches the knife in the same spot that it contacted the table? Try
> it and let us know how it works out. You can always use the single
> indicator solution (with spherical indicator point) to check the
> accuracy of the results.
>
> > The table saw gauge is more complicated. I am assuming that a warped
blade
> > is cupped such that you can turn it so that the curve is in the vertical
> > direction. I'm not sure how to describe this in words. Imagine looking
at
> > the blade from the side and seeing something shaped like a left bracket
( .
>
> Yes, I know what you are talking about. It's called "bi-lateral
> symmetry". You are assuming that there is an orientation of the blade
> such that every point on one side of a centerline has a corresponding
> point on the other side. You can probably find blades like this. You
> might even own some. But, there is no guarantee that all blades will
> exhibit bi-lateral symmetry.
>
> > If the warpage is more like a ripple than a cup, then what I am
proposing
> > won't work. I'll have to measure a few of my blades and see just what
they
> > look like.
>
> It could still be shaped like a cup (bi-lateral) but not be
> symmetrical. Don't make the mistake of thinking that some small
> sample of blades (yours for example) are representative of all blades.
>
> > The only reason I mentioned your product by name was that everyone knows
> > what I'm talking about when they hear it. If there was a popular brand
of
> > jointer gauge like the one I was talking about (Oneway and Powermatic
make
> > one--I've seen several more), I would have used that name. In
retrospect,
> > it was a bad idea.
>
> Sure, I understand. And, I'm sure you understand why it's important
> for me to defend the hard earned reputation of my products against
> untested ideas which violate basic Metrological principles.
>
> Ed Bennett
> [email protected]
> http://www.ts-aligner.com
I've had the 6" and 4" calipers for several years and really like them. The
4" fits nicely in my pocket.
What's wrong with a vernier? They are difficult to read at an angle or in
dim light. You can't zero them out when partially open to do a comparison
reading. You can't switch to metric at the push of a button. And when
taking dozens of readings, they take a long time. Comparing a digital
caliper to a vernier is like comparing a calculator to slide rule.
I've also been very happy with HF's dial indictors (normally around $13 but
frequently on sale for around $7). Dial indicators are very useful when you
have more than one. Many tools (such as the TS Aligner Jr, and numerous
height gauges used to set jointer/shaper blades) use outdated designs which
assume only one Starrett (or Starrett like) indicator at $100+ (ie. you only
have one). But these tools could do a far better and quicker job if they
were designed to use 2 or 3 indicators.
"patrick conroy" <[email protected]> wrote in message
news:[email protected]...
> The Starrett Buy American thread reminded me to chime in with a personal
> experience on:
> http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=47257
>
> I've had mine for two years now - it's great! Used enough to be on Battery
> #3.
> While I don't have a machinist's reference point to calibrate it to - I've
> measured a number of off the shelf items - drill bits, chisels, screws,
etc.
> This unit is within a few thousands of what you'd assume it would report.
As
> for accuracy, it again seems to put up data repeatable to a thou or so...
>
> If all the units are as nice as mine, I think it's a great buy at $16.
>
>
Turn the "chuck"? You must be joking.
"AL" <[email protected]> wrote in message news:DNk2d.445185$%_6.36090@attbi_s01...
> As I said, you square it against the table by getting all 3 indicators to
> read the same. To elaborate, you let all three stems touch the table,
then
> turn the chuck so that the three read the same. When this happens, the
jig
> is square to the table. Then clamp the spindle. It is a few seconds of
> work.
>
> "Jim Behning" <[email protected]> wrote in message
> news:[email protected]...
> > How do you square the 3 dial jig in the chuck? One indicator in a
> > locked chuck and all you have to do is a sweep to check. Does it take
> > hours to establish that the jig is square? What jig does it take to
> > make sure the 3 indicator jig is square or parallel or plumb or choose
> > your word?
> >
> > "AL" <[email protected]> wrote:
> >
> > >Aligning a mill vise with two indicators would take longer because the
> jig
> > >used to do the alignment was designed for one indicator (ie. clamp the
> > >indicator in the chuck and sweep the fixed jaw). Imagine a jig that
you
> > >clamp in the chuck/collet/holder that holds 3 indicators (all factory
> > >calibrated to read the same). The center indicator is centered with
the
> > >shaft in the chuck/collet/holder. All you have to do square the jig
> against
> > >the table (ie. all 3 indicators read the same), clamp the spindle, then
> > >adjust the vise so that the two outside indicators read the same as the
> > >middle one. No more sweeping.
> > >
> > >"CW" <no adddress@spam free.com> wrote in message
> > >news:[email protected]...
> > >> Not at all. Dial indicators were developed by, and are used
extensively
> in
> > >> the metalworking industry. The reason for using a single gage is the
> > >> elimination of variables. The cost of indicators has never been a
> factor
> > >to
> > >> them. They have always been relatively cheap. For someone using an
> > >indicator
> > >> for alignment at home, two might seem easier. For me (machinist),
> setting
> > >> two indicators to do a simple alignment (mill vise, or tablesaw
blade)
> > >would
> > >> increase the time to do the job.
> > >> "AL" <[email protected]> wrote in message
> > >news:n4a1d.183004$Fg5.53426@attbi_s53...
> > >> > My whole point is that people who design the gauges are stuck with
an
> > >> > outdated way of thinking that says "dial indicators are expensive
so
> my
> > >> > design will only use one".
> > >> >
> > >>
> > >>
> > >
> >
>
>
"AL" <[email protected]> wrote:
> Many tools (such as the TS Aligner Jr, and numerous
>height gauges used to set jointer/shaper blades) use outdated designs which
>assume only one Starrett (or Starrett like) indicator at $100+ (ie. you only
>have one). But these tools could do a far better and quicker job if they
>were designed to use 2 or 3 indicators.
I'm not very well versed in the nuances of alignment and set up jigs
for machinery, but I'm very intrigued by your line of thinking. Could
you elaborate a little on how you would envision a multiple gauge to
work, and why it would be better and quicker? Thanks.
JP
********************
Now you've got me thinking....
On Sun, 12 Sep 2004 10:49:30 -0500, Phil <[email protected]> calmly
ranted:
>Much easier to read without my reader glasses.
What's that, Stubby? (What fool works in the shop
without their glasses on?)
>AArDvarK wrote:
>
>> > The repeatability is precision. Accuracy is how close to the real value
>> > you get.
>> > "0.900, 0.901, 0.899, 0.902, 0.898" is precision.
>> > "1.00, 0.50, 1.50, 1.25, 0.75" is accuracy.
>> > You want both. "1.000, 1.001, 0.999, 1.002, 0.998"
>> > Anyway, for $16 I want one too. I'm considering a Stanley 136, because I'm
>> > looking for "neighborhood", not accuracy and precision.
>>
>> Tell me, what is wrong with using a regular mechanical vernier caliper?
>> Alex
-------------------------------------------------------------
give me The Luxuries Of Life * http://www.diversify.com
i can live without the necessities * 2 Tee collections online
-------------------------------------------------------------
On 16 Sep 2004 15:07:15 -0700, [email protected] (Ed Bennett) wrote:
>"AL" <[email protected]> wrote in message news:<c3x0d.167747$Fg5.165667@attbi_s53>...
>
><snip>
>
>> Many tools (such as the TS Aligner Jr, and numerous
>> height gauges used to set jointer/shaper blades) use outdated designs which
>> assume only one Starrett (or Starrett like) indicator at $100+ (ie. you only
>> have one). But these tools could do a far better and quicker job if they
>> were designed to use 2 or 3 indicators.
>
>I'd take exception to this statement. With any experience or training
>in Metrology, a person can easily see right through this reasoning
>pretty quickly. Or, if you just try an idea like this you'll
>immediately recognize it's folly. Multiple indicators don't make
>anything better or quicker or easier.
>
>Ed Bennett
>[email protected]
unless you're measuring travel in 2 directions simultaneously on the
cross slide on your metal lathe.
which of course we wouldn't do here. it's not woodworking.....
On Thu, 16 Sep 2004 11:56:21 GMT, Jim Behning
<[email protected]> wrote:
>How do you square the 3 dial jig in the chuck? One indicator in a
>locked chuck and all you have to do is a sweep to check. Does it take
>hours to establish that the jig is square? What jig does it take to
>make sure the 3 indicator jig is square or parallel or plumb or choose
>your word?
he's using magic- "factory calibrated to read the same".
I don't think he's used indicators much.
>
>"AL" <[email protected]> wrote:
>
>>Aligning a mill vise with two indicators would take longer because the jig
>>used to do the alignment was designed for one indicator (ie. clamp the
>>indicator in the chuck and sweep the fixed jaw). Imagine a jig that you
>>clamp in the chuck/collet/holder that holds 3 indicators (all factory
>>calibrated to read the same). The center indicator is centered with the
>>shaft in the chuck/collet/holder. All you have to do square the jig against
>>the table (ie. all 3 indicators read the same), clamp the spindle, then
>>adjust the vise so that the two outside indicators read the same as the
>>middle one. No more sweeping.
>>
>>"CW" <no adddress@spam free.com> wrote in message
>>news:[email protected]...
>>> Not at all. Dial indicators were developed by, and are used extensively in
>>> the metalworking industry. The reason for using a single gage is the
>>> elimination of variables. The cost of indicators has never been a factor
>>to
>>> them. They have always been relatively cheap. For someone using an
>>indicator
>>> for alignment at home, two might seem easier. For me (machinist), setting
>>> two indicators to do a simple alignment (mill vise, or tablesaw blade)
>>would
>>> increase the time to do the job.
>>> "AL" <[email protected]> wrote in message
>>news:n4a1d.183004$Fg5.53426@attbi_s53...
>>> > My whole point is that people who design the gauges are stuck with an
>>> > outdated way of thinking that says "dial indicators are expensive so my
>>> > design will only use one".
>>> >
>>>
>>>
>>
On Fri, 10 Sep 2004 20:00:20 -0700, "AArDvarK" <[email protected]>
wrote:
>
>> The repeatability is precision. Accuracy is how close to the real value
>> you get.
>> "0.900, 0.901, 0.899, 0.902, 0.898" is precision.
>> "1.00, 0.50, 1.50, 1.25, 0.75" is accuracy.
>> You want both. "1.000, 1.001, 0.999, 1.002, 0.998"
>> Anyway, for $16 I want one too. I'm considering a Stanley 136, because I'm
>> looking for "neighborhood", not accuracy and precision.
>
>
>Tell me, what is wrong with using a regular mechanical vernier caliper?
>Alex
>
I have a vernier caliper I bought about 20 years ago. it's still
plenty accurate and the batteries haven't gone out on it yet....
On Sat, 11 Sep 2004 06:42:55 GMT, "AL" <[email protected]> wrote:
>Have you considered attaching one of these to your planer?
>
>http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=12581&item=3839370322&rd=1
>
Nope. Up until you posted the above, I didn't realize these existed.
Thanks -- even better.
>I just received mine and will be attaching it to my Ridgid planer in a few
>weeks (I have a few other projects to finish first). I'll post after I
>install it.
>
Please do so, I would be very interested in any photos and/or
descriptions of how you mounted it.
Thanks -- definitely a better solution than jury-rigging a caliper
>
>"Mark & Juanita" <[email protected]> wrote in message
>news:[email protected]...
>> On Sat, 11 Sep 2004 00:11:37 GMT, "patrick conroy"
>> <[email protected]> wrote:
>>
>> >The Starrett Buy American thread reminded me to chime in with a personal
>> >experience on:
>> >http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=47257
>> >
>> >I've had mine for two years now - it's great! Used enough to be on
>Battery
>> >#3.
>> >While I don't have a machinist's reference point to calibrate it to -
>I've
>> >measured a number of off the shelf items - drill bits, chisels, screws,
>etc.
>> >This unit is within a few thousands of what you'd assume it would report.
>As
>> >for accuracy, it again seems to put up data repeatable to a thou or so...
>> >
>> >If all the units are as nice as mine, I think it's a great buy at $16.
>> >
>>
>>
>> I've been thinking about attaching one to my planer for quite some
>time,
>> but haven't pried open the wallet to buy one to drill holes in. This may
>> be the ticket if I can concoct an attachment method that doesn't look
>> totally jury-rigged.
>
The indicators are hanging below the spindle. At 90 degrees it is already
clear of the spindle. At 88 degrees, it is clear of the spindle and can
touch the top of the T slot. No dedicated setting fixture or calibrated
gauging surface required. Just check (once) if the the T slot or surface
table if flat and parallel to the axis of travel.
"CW" <no adddress@spam free.com> wrote in message
news:[email protected]...
> 2 degrees isn't even enough to clear the indicator spindle, let alone the
> body or the mounting lug. You'll be closer to 30 degrees by time you clear
> everything. So, you're saying that you are going to have a calibrated
> gagging surface on each machine. You are also going to have a dedicated
> setting fixture for each machine. Obviously, you are going to have to have
> calibration fixtures to calibrate those calibration surfaces and, as you
> seem to believe the dual indicator set up is the way to go, you are going
to
> need a calibration device to calibrate the calibration device that you are
> going to use to calibrate your calibration surfaces. Of course, there is
no
> telling if the original calibration device is correct. Might be close
enough
> in home shop where you can be reasonably sure of everything that goes on
> and the accuracy requirements of the work are not that close but in a
> commercial shop, forget it. To get back to your original thought. Why
would
> a commercial shop sell you an alignment device that is inherently less
> accurate, by design, than the one they used when making the device? Ever
> heard the old saying "anything that can go wrong, will"? Only make things
as
> complicated as they need to be to get the job done. Eliminate variables as
> much as possible.
>
> "AL" <[email protected]> wrote in message news:pbb3d.9625$wV.6942@attbi_s54...
> > You would need to check the T slot or table edge/side one time, not
every
> > time. You can also check the vise one time. On my mill, 2 degrees is
> > enough to access the T slot. I'm not trying to access the very bottom
of
> > it.
> >
> > "CW" <no adddress@spam free.com> wrote in message
> > news:[email protected]...
> > >
> > > "AL" <[email protected]> wrote in message
> > news:W7P2d.62468$MQ5.53211@attbi_s52...
> > > >
> > > > I concede that either the T slot or the side/edge of the table needs
> to
> > be
> > > > straight and parallel to the direction of travel for this to work.
> > > > Otherwise it won't.
> > >
> > > So, prior to setup, you calibrate the surface you are going to use for
> > > calibration. Are you going to use another one of your rigs that needs
to
> > be
> > > calibrated before you calibrate the calibration surface?
> > > >
> > > > On my mill, I estimate that the indicators would need to be tilted 2
> > > degrees
> > > > to access the T slot. Would a factor of cosine(2) or 0.99939 really
> > > reduce
> > > > the sensitivity of the indicator?
> > >
> > > More like 30 degrees in a 5/8 T slot. In addition to the measurement
> error
> > > that would be introduced, you now have put the indicator bearings in a
> > bind,
> > > further reducing sensitivity.
> > > >
> > > > I don't see why more than two hands would be required. Mount vise
on
> > > table.
> > > > Mount gauge in collet/holder/chuck. Raise knee, lower spindle, move
X
> > and
> > > > Y. Up to this point, you would have to do all of this regardless of
> > > whether
> > > > you are using one indicator, or more than one. When doing this,
stop
> > when
> > > > the indicators touch the T slot or edge of table near the vise.
> Square
> > > the
> > > > gauge by turning spindle with one finger (see other post). No need
to
> > > dial
> > > > for zero. Both gauges just need to read the same. Clamp the
spindle.
> > > > Raise the spindle slightly, and move the X axis slightly so that the
> > > > indicators touch the vise jaw. Now adjust the vise so that both
> > > indicators
> > > > read the same (they don't have to read zero).
> > >
> > > You are going to rotate that spindle .0001 or so and then expect that
it
> > > will maintain position while you clamp it... Right.
> > > >
> > > > You wouldn't move the vise so that the indicator points fall into
(for
> > > > example), the vise jaw mounting holes. If the vise jaw isn't
> straight,
> > > > you'll have problems regardless of how many indicators you're using.
> > >
> > > So, now you are just going to go on blind faith that the vise jaws are
> > true.
> > > The time to find this out is before you scrap a part. With your rig,
> you'd
> > > never know. This is kind of like measuring the height of a wall with a
6
> > > inch scale or, something many here will really relate to, using 4
> > different
> > > tape measures on the same job. It might work but chances are it won't
> and
> > > you can't be certain until you have produced scrap.
> > > >
> > > >
> > > >
> > >
> > >
> >
> >
>
>
"AL" <[email protected]> wrote:
snip of multi-gauge discussion
Are there gauges that can be retrofitted for multiple dial indicators,
or is this something that you'd need to create from scratch? Given
the low cost of highly accurate (or is it precise?) gauges, I'm
surprised their aren't a whole bunch of commercially available,
multiple gauge alignment aides.
My gut tells me that I should first learn how to tune machinery using
the most rudimentary jigs and devices, so the physics of the process
become very clear. Then I can better evaluate whether a certain jig
is timesaving and/or more accurate.
JP
*****************************
Give yourself the best chance to do excellent work.
I didn't understand what you meant by bed extension until I read it again.
When I get off my butt and install my DRO, I'll push the up and down arrows
to accomodate the sled. Or I'll adjust the planer so that it just touches
the sled, and then zero out the display.
"Mark & Juanita" <[email protected]> wrote in message
news:[email protected]...
> On Sat, 11 Sep 2004 05:23:03 GMT, patriarch
> <<patriarch>[email protected]> wrote:
>
> >Mark & Juanita <[email protected]> wrote in
> >news:[email protected]:
> >
> ><snip>
> >>
> >> I've been thinking about attaching one to my planer for quite some
> >> time,
> >> but haven't pried open the wallet to buy one to drill holes in. This
> >> may be the ticket if I can concoct an attachment method that doesn't
> >> look totally jury-rigged.
> >>
> >While you're puzzling on that problem, see if you can add in some sort of
> >solution flexibility for use, having inserted a bed extension. The kind
> >one uses for thinner stock, and to reduce snipe.
> >
>
> Doh! Hadn't considered that possibility. Maybe making the sled a precise
> even thickness (1" sounds good) might work.
>
> Haven't had any problems with snipe on my planer, but use of a sled for
> thinner stock is something to consider.
>
> >Preferably something that doesn't require me to do addition including
> >measurements in 32nds of an inch.
> >
> >If you get the time. And are interested. And don't mind sharing. For
> >free.
> >
>
> If you have the patience to wait for when I get a round tuit for that
> task, I'll be more than happy to share.
>
> >I don't want much, do I? ;-)
> >
>
> nah, not much. :-)
>
> >Patriarch
>
My whole point is that people who design the gauges are stuck with an
outdated way of thinking that says "dial indicators are expensive so my
design will only use one".
Gauges that are designed from the beginning assuming multiple cheap
indicators won't work with just one. So you won't see gauges that can use
one indicator, or optionally use more.
"Jay Pique" <[email protected]> wrote in message
news:[email protected]...
> "AL" <[email protected]> wrote:
>
> snip of multi-gauge discussion
>
> Are there gauges that can be retrofitted for multiple dial indicators,
> or is this something that you'd need to create from scratch? Given
> the low cost of highly accurate (or is it precise?) gauges, I'm
> surprised their aren't a whole bunch of commercially available,
> multiple gauge alignment aides.
>
> My gut tells me that I should first learn how to tune machinery using
> the most rudimentary jigs and devices, so the physics of the process
> become very clear. Then I can better evaluate whether a certain jig
> is timesaving and/or more accurate.
>
> JP
> *****************************
> Give yourself the best chance to do excellent work.
2 degrees isn't even enough to clear the indicator spindle, let alone the
body or the mounting lug. You'll be closer to 30 degrees by time you clear
everything. So, you're saying that you are going to have a calibrated
gagging surface on each machine. You are also going to have a dedicated
setting fixture for each machine. Obviously, you are going to have to have
calibration fixtures to calibrate those calibration surfaces and, as you
seem to believe the dual indicator set up is the way to go, you are going to
need a calibration device to calibrate the calibration device that you are
going to use to calibrate your calibration surfaces. Of course, there is no
telling if the original calibration device is correct. Might be close enough
in home shop where you can be reasonably sure of everything that goes on
and the accuracy requirements of the work are not that close but in a
commercial shop, forget it. To get back to your original thought. Why would
a commercial shop sell you an alignment device that is inherently less
accurate, by design, than the one they used when making the device? Ever
heard the old saying "anything that can go wrong, will"? Only make things as
complicated as they need to be to get the job done. Eliminate variables as
much as possible.
"AL" <[email protected]> wrote in message news:pbb3d.9625$wV.6942@attbi_s54...
> You would need to check the T slot or table edge/side one time, not every
> time. You can also check the vise one time. On my mill, 2 degrees is
> enough to access the T slot. I'm not trying to access the very bottom of
> it.
>
> "CW" <no adddress@spam free.com> wrote in message
> news:[email protected]...
> >
> > "AL" <[email protected]> wrote in message
> news:W7P2d.62468$MQ5.53211@attbi_s52...
> > >
> > > I concede that either the T slot or the side/edge of the table needs
to
> be
> > > straight and parallel to the direction of travel for this to work.
> > > Otherwise it won't.
> >
> > So, prior to setup, you calibrate the surface you are going to use for
> > calibration. Are you going to use another one of your rigs that needs to
> be
> > calibrated before you calibrate the calibration surface?
> > >
> > > On my mill, I estimate that the indicators would need to be tilted 2
> > degrees
> > > to access the T slot. Would a factor of cosine(2) or 0.99939 really
> > reduce
> > > the sensitivity of the indicator?
> >
> > More like 30 degrees in a 5/8 T slot. In addition to the measurement
error
> > that would be introduced, you now have put the indicator bearings in a
> bind,
> > further reducing sensitivity.
> > >
> > > I don't see why more than two hands would be required. Mount vise on
> > table.
> > > Mount gauge in collet/holder/chuck. Raise knee, lower spindle, move X
> and
> > > Y. Up to this point, you would have to do all of this regardless of
> > whether
> > > you are using one indicator, or more than one. When doing this, stop
> when
> > > the indicators touch the T slot or edge of table near the vise.
Square
> > the
> > > gauge by turning spindle with one finger (see other post). No need to
> > dial
> > > for zero. Both gauges just need to read the same. Clamp the spindle.
> > > Raise the spindle slightly, and move the X axis slightly so that the
> > > indicators touch the vise jaw. Now adjust the vise so that both
> > indicators
> > > read the same (they don't have to read zero).
> >
> > You are going to rotate that spindle .0001 or so and then expect that it
> > will maintain position while you clamp it... Right.
> > >
> > > You wouldn't move the vise so that the indicator points fall into (for
> > > example), the vise jaw mounting holes. If the vise jaw isn't
straight,
> > > you'll have problems regardless of how many indicators you're using.
> >
> > So, now you are just going to go on blind faith that the vise jaws are
> true.
> > The time to find this out is before you scrap a part. With your rig,
you'd
> > never know. This is kind of like measuring the height of a wall with a 6
> > inch scale or, something many here will really relate to, using 4
> different
> > tape measures on the same job. It might work but chances are it won't
and
> > you can't be certain until you have produced scrap.
> > >
> > >
> > >
> >
> >
>
>
How do you square the 3 dial jig in the chuck? One indicator in a
locked chuck and all you have to do is a sweep to check. Does it take
hours to establish that the jig is square? What jig does it take to
make sure the 3 indicator jig is square or parallel or plumb or choose
your word?
"AL" <[email protected]> wrote:
>Aligning a mill vise with two indicators would take longer because the jig
>used to do the alignment was designed for one indicator (ie. clamp the
>indicator in the chuck and sweep the fixed jaw). Imagine a jig that you
>clamp in the chuck/collet/holder that holds 3 indicators (all factory
>calibrated to read the same). The center indicator is centered with the
>shaft in the chuck/collet/holder. All you have to do square the jig against
>the table (ie. all 3 indicators read the same), clamp the spindle, then
>adjust the vise so that the two outside indicators read the same as the
>middle one. No more sweeping.
>
>"CW" <no adddress@spam free.com> wrote in message
>news:[email protected]...
>> Not at all. Dial indicators were developed by, and are used extensively in
>> the metalworking industry. The reason for using a single gage is the
>> elimination of variables. The cost of indicators has never been a factor
>to
>> them. They have always been relatively cheap. For someone using an
>indicator
>> for alignment at home, two might seem easier. For me (machinist), setting
>> two indicators to do a simple alignment (mill vise, or tablesaw blade)
>would
>> increase the time to do the job.
>> "AL" <[email protected]> wrote in message
>news:n4a1d.183004$Fg5.53426@attbi_s53...
>> > My whole point is that people who design the gauges are stuck with an
>> > outdated way of thinking that says "dial indicators are expensive so my
>> > design will only use one".
>> >
>>
>>
>
On 18 Sep 2004 15:44:41 -0700, [email protected] (Ed Bennett) wrote:
>
>> The table saw gauge is more complicated. I am assuming that a warped blade
>> is cupped such that you can turn it so that the curve is in the vertical
>> direction. I'm not sure how to describe this in words. Imagine looking at
>> the blade from the side and seeing something shaped like a left bracket ( .
>
>Yes, I know what you are talking about. It's called "bi-lateral
>symmetry". You are assuming that there is an orientation of the blade
>such that every point on one side of a centerline has a corresponding
>point on the other side. You can probably find blades like this. You
>might even own some. But, there is no guarantee that all blades will
>exhibit bi-lateral symmetry.
null axis of the warp......
<GD&R>
Even something as small as a Bridgeport would be damn difficult to position
with any precision by hand. Try it on a 100 horse power CNC.
"AL" <[email protected]> wrote in message news:xut2d.204942$mD.46877@attbi_s02...
> I'm not sure what you mean by joking. I mean turn the chuck my hand, not
> turn the machine on. Collet? End mill holder? Whatever. You have to
> clamp the jig in something.
>
> "CW" <no adddress@spam free.com> wrote in message
> news:[email protected]...
> > Turn the "chuck"? You must be joking.
> >
> > "AL" <[email protected]> wrote in message
> news:DNk2d.445185$%_6.36090@attbi_s01...
> > > As I said, you square it against the table by getting all 3 indicators
> to
> > > read the same. To elaborate, you let all three stems touch the table,
> > then
> > > turn the chuck so that the three read the same. When this happens,
the
> > jig
> > > is square to the table. Then clamp the spindle. It is a few seconds
of
> > > work.
> > >
> > > "Jim Behning" <[email protected]> wrote in
message
> > > news:[email protected]...
> > > > How do you square the 3 dial jig in the chuck? One indicator in a
> > > > locked chuck and all you have to do is a sweep to check. Does it
take
> > > > hours to establish that the jig is square? What jig does it take to
> > > > make sure the 3 indicator jig is square or parallel or plumb or
choose
> > > > your word?
> > > >
> > > > "AL" <[email protected]> wrote:
> > > >
> > > > >Aligning a mill vise with two indicators would take longer because
> the
> > > jig
> > > > >used to do the alignment was designed for one indicator (ie. clamp
> the
> > > > >indicator in the chuck and sweep the fixed jaw). Imagine a jig
that
> > you
> > > > >clamp in the chuck/collet/holder that holds 3 indicators (all
factory
> > > > >calibrated to read the same). The center indicator is centered
with
> > the
> > > > >shaft in the chuck/collet/holder. All you have to do square the
jig
> > > against
> > > > >the table (ie. all 3 indicators read the same), clamp the spindle,
> then
> > > > >adjust the vise so that the two outside indicators read the same as
> the
> > > > >middle one. No more sweeping.
> > > > >
> > > > >"CW" <no adddress@spam free.com> wrote in message
> > > > >news:[email protected]...
> > > > >> Not at all. Dial indicators were developed by, and are used
> > extensively
> > > in
> > > > >> the metalworking industry. The reason for using a single gage is
> the
> > > > >> elimination of variables. The cost of indicators has never been a
> > > factor
> > > > >to
> > > > >> them. They have always been relatively cheap. For someone using
an
> > > > >indicator
> > > > >> for alignment at home, two might seem easier. For me (machinist),
> > > setting
> > > > >> two indicators to do a simple alignment (mill vise, or tablesaw
> > blade)
> > > > >would
> > > > >> increase the time to do the job.
> > > > >> "AL" <[email protected]> wrote in message
> > > > >news:n4a1d.183004$Fg5.53426@attbi_s53...
> > > > >> > My whole point is that people who design the gauges are stuck
> with
> > an
> > > > >> > outdated way of thinking that says "dial indicators are
expensive
> > so
> > > my
> > > > >> > design will only use one".
> > > > >> >
> > > > >>
> > > > >>
> > > > >
> > > >
> > >
> > >
> >
> >
>
>
I agree it introduces more variables, but I don't think it will take longer
than sweeping the vise back and forth.
"CW" <no adddress@spam free.com> wrote in message
news:[email protected]...
> As I said before. Your setup introduces more variables and takes longer to
> do the job as you have to calibrate.
> "AL" <[email protected]> wrote in message
> news:MRk2d.445194$%_6.217615@attbi_s01...
> > What you call magic, I call child's play.
> >
> > The three indicators need to read the same to work. Adjusting them at
the
> > factory is child's play. Merely a setscrew that allows the indicator to
> > slide back and forth.
> >
> > If you want to do your own calibration, you merely need to use a
> machinists
> > square. One leg against the indicator stems, another leg against the
edge
> > of the holder (that has been machined square).
> >
> > I use indicators all the time. I don't handicap myself by doing things
> the
> > traditional way.
> >
> >
>
>
On Sat, 11 Sep 2004 00:11:37 +0000, patrick conroy wrote:
> for accuracy, it again seems to put up data repeatable to a thou or so...
The repeatability is precision. Accuracy is how close to the real value
you get.
"0.900, 0.901, 0.899, 0.902, 0.898" is precision.
"1.00, 0.50, 1.50, 1.25, 0.75" is accuracy.
You want both. "1.000, 1.001, 0.999, 1.002, 0.998"
Anyway, for $16 I want one too. I'm considering a Stanley 136, because I'm
looking for "neighborhood", not accuracy and precision.
--
"Keep your ass behind you"
On Fri, 10 Sep 2004 20:00:20 -0700, AArDvarK wrote:
> Tell me, what is wrong with using a regular mechanical vernier caliper
I want one of them too. :) Don't trust General, can't afford Starrett.
Don't need it anyway. Still want one, though. But, you're right, a
mechanical caliper is just fine. (I keep a slide rule in my bench drawer,
and use it now and again.)
--
"Keep your ass behind you"
You would need to check the T slot or table edge/side one time, not every
time. You can also check the vise one time. On my mill, 2 degrees is
enough to access the T slot. I'm not trying to access the very bottom of
it.
"CW" <no adddress@spam free.com> wrote in message
news:[email protected]...
>
> "AL" <[email protected]> wrote in message
news:W7P2d.62468$MQ5.53211@attbi_s52...
> >
> > I concede that either the T slot or the side/edge of the table needs to
be
> > straight and parallel to the direction of travel for this to work.
> > Otherwise it won't.
>
> So, prior to setup, you calibrate the surface you are going to use for
> calibration. Are you going to use another one of your rigs that needs to
be
> calibrated before you calibrate the calibration surface?
> >
> > On my mill, I estimate that the indicators would need to be tilted 2
> degrees
> > to access the T slot. Would a factor of cosine(2) or 0.99939 really
> reduce
> > the sensitivity of the indicator?
>
> More like 30 degrees in a 5/8 T slot. In addition to the measurement error
> that would be introduced, you now have put the indicator bearings in a
bind,
> further reducing sensitivity.
> >
> > I don't see why more than two hands would be required. Mount vise on
> table.
> > Mount gauge in collet/holder/chuck. Raise knee, lower spindle, move X
and
> > Y. Up to this point, you would have to do all of this regardless of
> whether
> > you are using one indicator, or more than one. When doing this, stop
when
> > the indicators touch the T slot or edge of table near the vise. Square
> the
> > gauge by turning spindle with one finger (see other post). No need to
> dial
> > for zero. Both gauges just need to read the same. Clamp the spindle.
> > Raise the spindle slightly, and move the X axis slightly so that the
> > indicators touch the vise jaw. Now adjust the vise so that both
> indicators
> > read the same (they don't have to read zero).
>
> You are going to rotate that spindle .0001 or so and then expect that it
> will maintain position while you clamp it... Right.
> >
> > You wouldn't move the vise so that the indicator points fall into (for
> > example), the vise jaw mounting holes. If the vise jaw isn't straight,
> > you'll have problems regardless of how many indicators you're using.
>
> So, now you are just going to go on blind faith that the vise jaws are
true.
> The time to find this out is before you scrap a part. With your rig, you'd
> never know. This is kind of like measuring the height of a wall with a 6
> inch scale or, something many here will really relate to, using 4
different
> tape measures on the same job. It might work but chances are it won't and
> you can't be certain until you have produced scrap.
> >
> >
> >
>
>
Aligning a mill vise with two indicators would take longer because the jig
used to do the alignment was designed for one indicator (ie. clamp the
indicator in the chuck and sweep the fixed jaw). Imagine a jig that you
clamp in the chuck/collet/holder that holds 3 indicators (all factory
calibrated to read the same). The center indicator is centered with the
shaft in the chuck/collet/holder. All you have to do square the jig against
the table (ie. all 3 indicators read the same), clamp the spindle, then
adjust the vise so that the two outside indicators read the same as the
middle one. No more sweeping.
"CW" <no adddress@spam free.com> wrote in message
news:[email protected]...
> Not at all. Dial indicators were developed by, and are used extensively in
> the metalworking industry. The reason for using a single gage is the
> elimination of variables. The cost of indicators has never been a factor
to
> them. They have always been relatively cheap. For someone using an
indicator
> for alignment at home, two might seem easier. For me (machinist), setting
> two indicators to do a simple alignment (mill vise, or tablesaw blade)
would
> increase the time to do the job.
> "AL" <[email protected]> wrote in message
news:n4a1d.183004$Fg5.53426@attbi_s53...
> > My whole point is that people who design the gauges are stuck with an
> > outdated way of thinking that says "dial indicators are expensive so my
> > design will only use one".
> >
>
>
On Sat, 11 Sep 2004 05:23:03 GMT, patriarch
<<patriarch>[email protected]> wrote:
>Mark & Juanita <[email protected]> wrote in
>news:[email protected]:
>
><snip>
>>
>> I've been thinking about attaching one to my planer for quite some
>> time,
>> but haven't pried open the wallet to buy one to drill holes in. This
>> may be the ticket if I can concoct an attachment method that doesn't
>> look totally jury-rigged.
>>
>While you're puzzling on that problem, see if you can add in some sort of
>solution flexibility for use, having inserted a bed extension. The kind
>one uses for thinner stock, and to reduce snipe.
>
Doh! Hadn't considered that possibility. Maybe making the sled a precise
even thickness (1" sounds good) might work.
Haven't had any problems with snipe on my planer, but use of a sled for
thinner stock is something to consider.
>Preferably something that doesn't require me to do addition including
>measurements in 32nds of an inch.
>
>If you get the time. And are interested. And don't mind sharing. For
>free.
>
If you have the patience to wait for when I get a round tuit for that
task, I'll be more than happy to share.
>I don't want much, do I? ;-)
>
nah, not much. :-)
>Patriarch
On Sat, 11 Sep 2004 13:08:02 -0500, "JohnT." <[email protected]>
wrote:
>You'd be surprised how many people find it hard to read a vernier or
>dial caliper! They just don't know how to read it, in most cases. As a
>machinist/moldmaker, my most used tool is a 12" dial calipers.
>
>I have a cheapie 6" at home I use for everything...machining, planing, etc.
>
>John
I prefer the dial ones too, especially the ones that have English
fractions on the dial.
I gotta wade in here. You DO have to ground a caliper - and here's a case in
point.
My brother had to wear a caliper as a boy, it's a device that is two metal
rods hinged, at the knee, that supports the leg. He had to wear it for
extended periods following operations. The metal bits were kept off the leg
by leather but, at the top, they were exposed. The top terminated near the
upper thigh, and, on a good day with the right conditions, you could scuff
yourself over the carpet and touch the bottom of the caliper, resulting in a
discharge near the top (where his boyz were).
It were guar-ant-eed to get his attention.
So, in answer to your statement, no shop explosions, but it did make my
brudder explode regularly.
--
Greg
"Mark & Juanita" <[email protected]> wrote in message
news:1095043133.//okkvx0S0kzsgGqjg9vgg@teranews...
> On Sun, 12 Sep 2004 20:38:39 GMT, Unisaw A100 <[email protected]>
> wrote:
>
>>AArDvarK wrote:
>>>Take a click:
>>>http://www.rit.edu/%7Euphysics/VernierCaliper/caliper.html
>>
>>
>>Absolutely useless. Not a thing said about how to properly
>>ground a caliper.
>>
>>UA100
>
> You don't need to ground a caliper, that's just a myth. Nobody has ever
> presented a single example of a shop explosion caused by an ungrounded
> caliper.
>
>
> :-)
I'm not sure what you mean by joking. I mean turn the chuck my hand, not
turn the machine on. Collet? End mill holder? Whatever. You have to
clamp the jig in something.
"CW" <no adddress@spam free.com> wrote in message
news:[email protected]...
> Turn the "chuck"? You must be joking.
>
> "AL" <[email protected]> wrote in message
news:DNk2d.445185$%_6.36090@attbi_s01...
> > As I said, you square it against the table by getting all 3 indicators
to
> > read the same. To elaborate, you let all three stems touch the table,
> then
> > turn the chuck so that the three read the same. When this happens, the
> jig
> > is square to the table. Then clamp the spindle. It is a few seconds of
> > work.
> >
> > "Jim Behning" <[email protected]> wrote in message
> > news:[email protected]...
> > > How do you square the 3 dial jig in the chuck? One indicator in a
> > > locked chuck and all you have to do is a sweep to check. Does it take
> > > hours to establish that the jig is square? What jig does it take to
> > > make sure the 3 indicator jig is square or parallel or plumb or choose
> > > your word?
> > >
> > > "AL" <[email protected]> wrote:
> > >
> > > >Aligning a mill vise with two indicators would take longer because
the
> > jig
> > > >used to do the alignment was designed for one indicator (ie. clamp
the
> > > >indicator in the chuck and sweep the fixed jaw). Imagine a jig that
> you
> > > >clamp in the chuck/collet/holder that holds 3 indicators (all factory
> > > >calibrated to read the same). The center indicator is centered with
> the
> > > >shaft in the chuck/collet/holder. All you have to do square the jig
> > against
> > > >the table (ie. all 3 indicators read the same), clamp the spindle,
then
> > > >adjust the vise so that the two outside indicators read the same as
the
> > > >middle one. No more sweeping.
> > > >
> > > >"CW" <no adddress@spam free.com> wrote in message
> > > >news:[email protected]...
> > > >> Not at all. Dial indicators were developed by, and are used
> extensively
> > in
> > > >> the metalworking industry. The reason for using a single gage is
the
> > > >> elimination of variables. The cost of indicators has never been a
> > factor
> > > >to
> > > >> them. They have always been relatively cheap. For someone using an
> > > >indicator
> > > >> for alignment at home, two might seem easier. For me (machinist),
> > setting
> > > >> two indicators to do a simple alignment (mill vise, or tablesaw
> blade)
> > > >would
> > > >> increase the time to do the job.
> > > >> "AL" <[email protected]> wrote in message
> > > >news:n4a1d.183004$Fg5.53426@attbi_s53...
> > > >> > My whole point is that people who design the gauges are stuck
with
> an
> > > >> > outdated way of thinking that says "dial indicators are expensive
> so
> > my
> > > >> > design will only use one".
> > > >> >
> > > >>
> > > >>
> > > >
> > >
> >
> >
>
>
I found it:
http://www.shumatech.com/support/chinese_scales.htm#Digimatic%20Protocol
"AL" <[email protected]> wrote in message news:Q3t3d.78643$D%.33927@attbi_s51...
> A few months ago I found a web page that described the interface. I just
> looked but couldn't find it. Try searching rec.crafts.metalworking on
> groups.google.com.
>
> A year ago, the vertical dro's were going for $50. Now they are $35. I
> suspect in a few years they will be $5 and people will be installing them
on
> their toilet seats.
>
>
>
> "Eric Anderson" <[email protected]> wrote in message
> news:[email protected]...
> > Absolutely unbelievable! I would never imagine that you can get these
> > readouts for this kind of money. I would certainly get the readouts
> > that are made for mounting on a tool for the $35 or so that they are
> > asking for them. You can jog the number up or down slightly to bring
> > it into the correct reading.
> >
> > By the way, where can I get the specs on the electrical interface? I
> > called Harbor Freight on that, but even though they said they would
> > get back to me, I don't think they will be able to find the info.
> > Where would I look? The caliper is a Cen-tech. Tried to look them up
> > with little success. If anyone knows who makes the readout or who in
> > this country might know what the interface is, let me know.
> >
> > "AL" <[email protected]> wrote in message
> news:<Hmb3d.217318$Fg5.99177@attbi_s53>...
> > > Yes, clamping or gluing is the way to go. Drilling the caliper arms
is
> > > difficult.
> > >
> > > For around double the cost, you can get horizontal and vertical dro's
> which
> > > look like Harbor Freight's digital calipers without the arms, but with
> > > mounting holes on both sides.
> > >
> > > Here is an example of a vertical one:
> > >
> > >
>
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=12581&item=3840273611&rd=1
> > >
> > > and here is an example of a horizontal one:
> > >
> > >
>
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=41939&item=3840604709&rd=1
> > >
> > > You can find better prices if you look for it.
> > >
> > > They also make very long ones, so you could put one on your table saw
> fence
> > > if you wanted to.
> > >
> > > Some dro's and most digital calipers have serial port connectors
> (intended
> > > for statistical process control) so you could mount one inside your
> table
> > > saw trunnion and put a separate display somewhere else (for example on
> the
> > > overhead guard if you have one). You could use it to display the
height
> of
> > > the blade.
> > >
> > > You could also have one display the angle of blade, but that is a bit
> > > tricky.
> > >
>
>