I just had another idea. If using an end mill holder, forget the spindle
lock, using the neutral lever, and turning the spindle by handle. Leave the
spindle in gear so that the weight of the gears, belts and motor keeps it in
place. Mount the gauge but leave the setscrew loose. When the gauge is
square, tighten the setscrew.
"AL" <[email protected]> wrote in message news:...
> 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.
> > >
> > >
> > >
> >
> >
>
>
So, this is where this discussion got off to!
I read through all the messages. Al, I have to say, you could benefit
from a lot more knowledge and experience. I applaud your ingenuity
and desire to invent new ways of doing things. But, if you're honest,
you'll have to admit that all of this is just conjecture. You really
haven't done any of this. How do I know this? Because your method
seems to evolve as objections are raised. You're talking to people
who have been doing it for a long time. It's not a matter of being
closed-minded to new ideas. It's a matter of knowing without a shread
of doubt that the multi-indicator idea is chock full of pitfalls.
And, you are stepping into most of these pitfalls without even knowing
it.
The single indicator method is very elegant, functional, efficient,
and most of all RELIABLY ACCURATE. I can't turn or clamp a spindle by
hand, any spindle on any machine, to 0.0001". But, I can very quickly
use a 0.0001"/div test indicator to align a vise in less time than it
takes for you to get your rig installed. I don't have to trust that
the table slots are aligned to the table motion. Honestly, I don't
even care! And, your rig would be useless on any machine where they
weren't (which is all the machines I've ever used!). Yes, they are
usually close, but not good enough to beat the single indicator
method.
Read, learn, practice, and understand how and why things are done. If
you don't, then your ideas won't benefit from the thousands upon
thousands of minds which have already pondered these things and
evaluated the alternatives. Without this benefit, you are likely to
stumble into all kinds of embarrassing pitfalls.
WRT the topic of the other thread:
"The sine angle caused by misalignment with a flat contact is a much
more serious cause for error than the cosine error" "Fundamentals of
Dimensional Metrology" Second Edition (c) 1989 Delmar Publishers Inc.
p. 264
The example given shows how a one degree tilt on your indicator can
cause more than 0.002" error in reading. That's with just one
indicator. You've proposed using two. The error multiplies! While
you're busy trying to align your indicators with less than one degree
of tilt, I've already aligned the knives on the jointer using just one
indicator and a round stylus point.
Read, learn, practice, understand, and then innovate. Your ideas will
gain much more respect and your life will be a lot easier.
Ed Bennett
[email protected]
http://www.ts-aligner.com
"AL" <[email protected]> wrote in message news:<5Pb3d.217331$Fg5.126720@attbi_s53>...
> I just had another idea. If using an end mill holder, forget the spindle
> lock, using the neutral lever, and turning the spindle by handle. Leave the
> spindle in gear so that the weight of the gears, belts and motor keeps it in
> place. Mount the gauge but leave the setscrew loose. When the gauge is
> square, tighten the setscrew.
> you'll have to admit that all of this is just conjecture
Absolutely! I never once said I already built the gauges I was describing.
"Ed Bennett" <[email protected]> wrote in message
news:[email protected]...
> So, this is where this discussion got off to!
>
> I read through all the messages. Al, I have to say, you could benefit
> from a lot more knowledge and experience. I applaud your ingenuity
> and desire to invent new ways of doing things. But, if you're honest,
> you'll have to admit that all of this is just conjecture. You really
> haven't done any of this. How do I know this? Because your method
> seems to evolve as objections are raised. You're talking to people
> who have been doing it for a long time. It's not a matter of being
> closed-minded to new ideas. It's a matter of knowing without a shread
> of doubt that the multi-indicator idea is chock full of pitfalls.
> And, you are stepping into most of these pitfalls without even knowing
> it.
>
> The single indicator method is very elegant, functional, efficient,
> and most of all RELIABLY ACCURATE. I can't turn or clamp a spindle by
> hand, any spindle on any machine, to 0.0001". But, I can very quickly
> use a 0.0001"/div test indicator to align a vise in less time than it
> takes for you to get your rig installed. I don't have to trust that
> the table slots are aligned to the table motion. Honestly, I don't
> even care! And, your rig would be useless on any machine where they
> weren't (which is all the machines I've ever used!). Yes, they are
> usually close, but not good enough to beat the single indicator
> method.
>
> Read, learn, practice, and understand how and why things are done. If
> you don't, then your ideas won't benefit from the thousands upon
> thousands of minds which have already pondered these things and
> evaluated the alternatives. Without this benefit, you are likely to
> stumble into all kinds of embarrassing pitfalls.
>
> WRT the topic of the other thread:
>
> "The sine angle caused by misalignment with a flat contact is a much
> more serious cause for error than the cosine error" "Fundamentals of
> Dimensional Metrology" Second Edition (c) 1989 Delmar Publishers Inc.
> p. 264
>
> The example given shows how a one degree tilt on your indicator can
> cause more than 0.002" error in reading. That's with just one
> indicator. You've proposed using two. The error multiplies! While
> you're busy trying to align your indicators with less than one degree
> of tilt, I've already aligned the knives on the jointer using just one
> indicator and a round stylus point.
>
> Read, learn, practice, understand, and then innovate. Your ideas will
> gain much more respect and your life will be a lot easier.
>
> Ed Bennett
> [email protected]
>
> http://www.ts-aligner.com
>
> "AL" <[email protected]> wrote in message
news:<5Pb3d.217331$Fg5.126720@attbi_s53>...
> > I just had another idea. If using an end mill holder, forget the
spindle
> > lock, using the neutral lever, and turning the spindle by handle. Leave
the
> > spindle in gear so that the weight of the gears, belts and motor keeps
it in
> > place. Mount the gauge but leave the setscrew loose. When the gauge is
> > square, tighten the setscrew.