I saw a video and article about the inexpensive tension gauge for the
bandsaw from John White in Fine Woodworking. I thought it was a great
idea, but since I have a number of dial and digital calipers, I
thought I would use a 6 inch caliper set with the jaws 5 inches
apart. I clamped the jaws to the blade just as he did his jig. I put
some tension on the 1/2 inch Suffolk Timberwolf blade just as he did
and set the dial to 0. I then started to crank tension on the blade.
I have no doubt that the standard spring is weak, but I don't see
really ANY MOVEMENT AT ALL from the caliper. I can't believe the
tension that I will need to get the recommended 15,000 psi. I will
collapse the spring and THEN some. I can't bring myself to put the
tension on the blade that would bring the 2.5 mils of displacement on
the caliper to get the 15,000 psi. Without some more confidence that
I am going the right way, I am afraid I will break the saw (and I will
be WAY past collapse of the spring). Can anyone tell me what I am
doing wrong? Has anyone done this and can tell me what did your
standard Delta gauge read (with the standard Delta spring) when you
put 15,000 (or whatever PSI you used)?
By the way, I know about all the different methods, such as the
flutter test, etc. I am doing this to get a feeling what a standard
tension is and then I will go my own way, but I would like to at least
experience what 15,000 psi is.
On Apr 1, 10:28=A0pm, "Leon" <[email protected]> wrote:
> "eganders" <[email protected]> wrote in message
>
> news:d3d27811-aed2-43e0-bc1d-b4a54d2d272f@e67g2000hsa.googlegroups.com...
>
>
>
>
>
> >I saw a video and article about the inexpensive tension gauge for the
> > bandsaw from John White in Fine Woodworking. =A0I thought it was a great=
> > idea, but since I have a number of dial and digital calipers, I
> > thought I would use a 6 inch caliper set with the jaws 5 inches
> > apart. =A0I clamped the jaws to the blade just as he did his jig. =A0I p=
ut
> > some tension on the 1/2 inch Suffolk Timberwolf blade just as he did
> > and set the dial to 0. =A0I then started to crank tension on the blade.
>
> > I have no doubt that the standard spring is weak, but I don't see
> > really ANY MOVEMENT AT ALL from the caliper. I can't believe the
> > tension that I will need to get the recommended 15,000 psi. =A0I will
> > collapse the spring and THEN some. =A0I can't bring myself to put the
> > tension on the blade that would bring the 2.5 mils of displacement on
> > the caliper to get the 15,000 psi. =A0Without some more confidence that
> > I am going the right way, I am afraid I will break the saw (and I will
> > be WAY past collapse of the spring). =A0Can anyone tell me what I am
> > doing wrong? =A0Has anyone done this and can tell me what did your
> > standard Delta gauge read (with the standard Delta spring) when you
> > put 15,000 (or whatever PSI you used)?
>
> > By the way, I know about all the different methods, such as the
> > flutter test, etc. =A0I am doing this to get a feeling what a standard
> > tension is and then I will go my own way, but I would like to at least
> > experience what 15,000 psi is.
>
> Some springs are not up to the challenge or have no longer go their origin=
al
> tension. =A0This could be why yours collapses. =A0More than likely your bl=
ade
> would break before your saw would.- Hide quoted text -
>
> - Show quoted text -
Maybe the blade would break, maybe not...how should I know... I sure
as hell don't want to find out.
BUT, I want experiences from people that have really TRIED this. Has
anyone measured the true tension on a Delta saw with a strain gauge
mechanism, calipers, shop made jig or some other scientific method and
can relate their ACTUAL experiences??? Does the standard Delta spring
collapse or not at 15,000 psi??
On Tue, 8 Apr 2008 18:06:49 -0600, eganders wrote
(in article
<6240ddb1-4a69-4bc3-9ab3-1495158be1c5@f63g2000hsf.googlegroups.com>):
>
> I used that approach (see my 1st post), but I did neglect to try
> something.
> I did the same thing with a 6 inch dial caliper, but my digital
> caliper does go down to .01 mm. It may not be super accurate, but it
> is more precise than my dial caliper. I can get about .03 mm over a
> 127 mm (5 inch) range, so I get about 7 KPSI. That is pretty good and
> maybe good enough for what I am after.
I used a dial gauge with 0.0001" resolution over 10" of blade span. It worked
well, but I really doubt something with 0.001 resolution would be 'accurate'
but it could be 'good enough'.
I'd do your measurement, strip down your setup, then repeat several times to
see your measurement variance (then average).
-Bruce
On Apr 8, 3:49=A0pm, "Swingman" <[email protected]> wrote:
> "eganders" wrote
>
> >How do you make a strain gauge device that measures the strain (change
> >in length) of a bandsaw by clamping the gauge device onto the metal
> >band.
>
> Check this out:
>
> http://www.sawmillcreek.org/showthread.php?t=3D22144
>
> --www.e-woodshop.net
> Last update: 3/27/08
> KarlC@ (the obvious)
I used that approach (see my 1st post), but I did neglect to try
something.
I did the same thing with a 6 inch dial caliper, but my digital
caliper does go down to .01 mm. It may not be super accurate, but it
is more precise than my dial caliper. I can get about .03 mm over a
127 mm (5 inch) range, so I get about 7 KPSI. That is pretty good and
maybe good enough for what I am after.
The Suffolk Timberwolf blade is designed as a low tension blade, I use it
resaw with, not a good blade for your test. Pick and Olson or something
else, this blade is to easy to set up and easy on your saw, (low tension)
you're going to collapse a wheel at such high tension on a old saw. My
$.02
Ken
"Nova" <[email protected]> wrote in message
news:eQPIj.3728$yd2.2613@trndny04...
> eganders wrote:
>> I saw a video and article about the inexpensive tension gauge for the
>> bandsaw from John White in Fine Woodworking. I thought it was a great
>> idea, but since I have a number of dial and digital calipers, I
>> thought I would use a 6 inch caliper set with the jaws 5 inches
>> apart. I clamped the jaws to the blade just as he did his jig. I put
>> some tension on the 1/2 inch Suffolk Timberwolf blade just as he did
>> and set the dial to 0. I then started to crank tension on the blade.
>>
>> I have no doubt that the standard spring is weak, but I don't see
>> really ANY MOVEMENT AT ALL from the caliper. I can't believe the
>> tension that I will need to get the recommended 15,000 psi. I will
>> collapse the spring and THEN some. I can't bring myself to put the
>> tension on the blade that would bring the 2.5 mils of displacement on
>> the caliper to get the 15,000 psi. Without some more confidence that
>> I am going the right way, I am afraid I will break the saw (and I will
>> be WAY past collapse of the spring). Can anyone tell me what I am
>> doing wrong? Has anyone done this and can tell me what did your
>> standard Delta gauge read (with the standard Delta spring) when you
>> put 15,000 (or whatever PSI you used)?
>>
>> By the way, I know about all the different methods, such as the
>> flutter test, etc. I am doing this to get a feeling what a standard
>> tension is and then I will go my own way, but I would like to at least
>> experience what 15,000 psi is.
>
> If 15,000 PSI is the recommended tension (I can find no such listing on
> Suffolk's site) it "Pounds Per Square Inch". You're dealing with a blade
> that has a cross section of .5" x .025" or .0125 sq. in..
>
> --
> Jack Novak
> Buffalo, NY - USA
> [email protected]
"eganders" wrote
> BUT, I want experiences from people that have really TRIED this. Has
> anyone measured the true tension on a Delta saw with a strain gauge
> mechanism, calipers, shop made jig or some other scientific method and
> can relate their ACTUAL experiences??? Does the standard Delta spring
> collapse or not at 15,000 psi??
I use an Iturra bandsaw tension gauge to set my Delta 14", but neither I,
nor anyone else, can answer your question with any authority because we
don't have your particular spring to test and we would be guessing at best.
Bandsaw tension springs, even when new, can vary as much as 30% in tension
pressures.
With the old Delta spring you would be lucky to get 15,000 psi on the Delta
14". But apparently with the newer springs (since circa 2005/6, IIRC), you
can, even to the point of exceeding the capacity of your bandsaw, to its
detriment.
This is according to the information in Louis Iturra's 2006 catalog.
You might want to call them for a copy ... basically an essential source of
information for owners of the Delta and Jet 14" light duty models.
1-866-883-8064
.. and by all means, get some kind of blade tension gauge if you plan on
getting the maximum performance out of your light duty bandsaw, particularly
when resawing. Not putting the proper tension on the resaw blade is like
putting a new set of tires on a racing car and guessing at the tire
pressure.
--
www.e-woodshop.net
Last update: 3/27/08
KarlC@ (the obvious)
"eganders" <[email protected]> wrote in message
news:[email protected]...
On Apr 1, 10:28 pm, "Leon" <[email protected]> wrote:
Maybe the blade would break, maybe not...how should I know... I sure
as hell don't want to find out.
Well If my saw could not be properly tensioned with out breaking I would
want to get a replacement saw, pronto. Which part do you fear will break?
On Apr 2, 12:09=A0pm, Frank Boettcher <[email protected]> wrote:
> On Wed, 2 Apr 2008 07:12:33 -0500, "Swingman" <[email protected]> wrote:
>
> >"eganders" wrote
>
> >> BUT, I want experiences from people that have really TRIED this. =A0Has=
> >> anyone measured the true tension on a Delta saw with astraingauge
> >> mechanism, calipers, shop made jig or some other scientific method and
> >> can relate their ACTUAL experiences??? =A0Does the standard Delta sprin=
g
> >> collapse or not at 15,000 psi??
>
> >I use an Iturra bandsaw tension gauge to set my Delta 14", but neither I,=
> >nor anyone else, can answer your question with any authority because we
> >don't have your particular spring to test and we would be guessing at bes=
t.
>
> >Bandsaw tension springs, even when new, can vary as much as 30% in tensio=
n
> >pressures.
>
> >With the old Delta spring you would be lucky to get 15,000 psi on the Del=
ta
> >14". But apparently with the newer springs (since circa 2005/6, IIRC), yo=
u
> >can, even to the point of exceeding the capacity of your bandsaw, to its
> >detriment.
>
> Good point. =A0At that point for sure and even prior to that point,
> other things start to give. =A0For instance, at the time of the change
> mentioned above, one of the things measured was the deflection of the
> overarm to determine if the whole package would work. =A0Like any
> mechanical device, just adding a tougher component (spring, HP of
> motor, wider blade, etc.) will only get you so far and then the
> weakest link limits.
>
> FYI, at the time of those changes, actually a little earlier than you
> stated, the domestic Delta overarm had the least deflection when
> tested against the imported units, competitor or Delta. =A0Don't know
> how they would stack up presently.
>
>
>
> >This is according to the information in Louis Iturra's 2006 catalog.
>
> A good source.
>
> Frank
>
>
>
>
>
> >You might want to call them for a copy ... basically an essential source =
of
> >information for owners of the Delta and Jet 14" light duty models.
>
> >1-866-883-8064
>
> >.. and by all means, get some kind of blade tension gauge if you plan on
> >getting the maximum performance out of your light duty bandsaw, particula=
rly
> >when resawing. Not putting the proper tension on the resaw blade is like
> >putting a new set of tires on a racing car and guessing at the tire
> >pressure.- Hide quoted text -
>
> - Show quoted text -- Hide quoted text -
>
> - Show quoted text -
In thinking about this further, I may change direction....
How do you make a strain gauge device that measures the strain (change
in length) of a bandsaw by clamping the gauge device onto the metal
band. The gauge would be an analog bridge strain gauge that would
have to have pads that allow them to be clamped on the metal band, but
the material that the gauge device was made of would have to have
little effect on the total resistance to elongation of the band, since
the band strain vs. force is what is being measured.
I know I could glue a strain gauge on the band itself to do the
measurement, but I want to be able to mount and unmount the strain
gauge on different bands.
Yes, I could buy a mechanical strain gauge to do the measurement, but
find that I can buy a used strain gauge meter for much less and if I
can make a gauge, I will have a strain gauge meter for use in other
applications. Also, I believe it could potentially be more accurate
also.
Any ideas?
eganders wrote:
> I saw a video and article about the inexpensive tension gauge for the
> bandsaw from John White in Fine Woodworking. I thought it was a great
> idea, but since I have a number of dial and digital calipers, I
> thought I would use a 6 inch caliper set with the jaws 5 inches
> apart. I clamped the jaws to the blade just as he did his jig. I put
> some tension on the 1/2 inch Suffolk Timberwolf blade just as he did
> and set the dial to 0. I then started to crank tension on the blade.
>
> I have no doubt that the standard spring is weak, but I don't see
> really ANY MOVEMENT AT ALL from the caliper. I can't believe the
> tension that I will need to get the recommended 15,000 psi. I will
> collapse the spring and THEN some. I can't bring myself to put the
> tension on the blade that would bring the 2.5 mils of displacement on
> the caliper to get the 15,000 psi. Without some more confidence that
> I am going the right way, I am afraid I will break the saw (and I will
> be WAY past collapse of the spring). Can anyone tell me what I am
> doing wrong? Has anyone done this and can tell me what did your
> standard Delta gauge read (with the standard Delta spring) when you
> put 15,000 (or whatever PSI you used)?
>
> By the way, I know about all the different methods, such as the
> flutter test, etc. I am doing this to get a feeling what a standard
> tension is and then I will go my own way, but I would like to at least
> experience what 15,000 psi is.
If 15,000 PSI is the recommended tension (I can find no such listing on
Suffolk's site) it "Pounds Per Square Inch". You're dealing with a
blade that has a cross section of .5" x .025" or .0125 sq. in..
--
Jack Novak
Buffalo, NY - USA
[email protected]
On Wed, 2 Apr 2008 07:12:33 -0500, "Swingman" <[email protected]> wrote:
>
>"eganders" wrote
>
>> BUT, I want experiences from people that have really TRIED this. Has
>> anyone measured the true tension on a Delta saw with a strain gauge
>> mechanism, calipers, shop made jig or some other scientific method and
>> can relate their ACTUAL experiences??? Does the standard Delta spring
>> collapse or not at 15,000 psi??
>
>I use an Iturra bandsaw tension gauge to set my Delta 14", but neither I,
>nor anyone else, can answer your question with any authority because we
>don't have your particular spring to test and we would be guessing at best.
>
>Bandsaw tension springs, even when new, can vary as much as 30% in tension
>pressures.
>
>With the old Delta spring you would be lucky to get 15,000 psi on the Delta
>14". But apparently with the newer springs (since circa 2005/6, IIRC), you
>can, even to the point of exceeding the capacity of your bandsaw, to its
>detriment.
Good point. At that point for sure and even prior to that point,
other things start to give. For instance, at the time of the change
mentioned above, one of the things measured was the deflection of the
overarm to determine if the whole package would work. Like any
mechanical device, just adding a tougher component (spring, HP of
motor, wider blade, etc.) will only get you so far and then the
weakest link limits.
FYI, at the time of those changes, actually a little earlier than you
stated, the domestic Delta overarm had the least deflection when
tested against the imported units, competitor or Delta. Don't know
how they would stack up presently.
>
>This is according to the information in Louis Iturra's 2006 catalog.
A good source.
Frank
>
>You might want to call them for a copy ... basically an essential source of
>information for owners of the Delta and Jet 14" light duty models.
>
>1-866-883-8064
>
>.. and by all means, get some kind of blade tension gauge if you plan on
>getting the maximum performance out of your light duty bandsaw, particularly
>when resawing. Not putting the proper tension on the resaw blade is like
>putting a new set of tires on a racing car and guessing at the tire
>pressure.
"eganders" <[email protected]> wrote in message
news:d3d27811-aed2-43e0-bc1d-b4a54d2d272f@e67g2000hsa.googlegroups.com...
>I saw a video and article about the inexpensive tension gauge for the
> bandsaw from John White in Fine Woodworking. I thought it was a great
> idea, but since I have a number of dial and digital calipers, I
> thought I would use a 6 inch caliper set with the jaws 5 inches
> apart. I clamped the jaws to the blade just as he did his jig. I put
> some tension on the 1/2 inch Suffolk Timberwolf blade just as he did
> and set the dial to 0. I then started to crank tension on the blade.
>
> I have no doubt that the standard spring is weak, but I don't see
> really ANY MOVEMENT AT ALL from the caliper. I can't believe the
> tension that I will need to get the recommended 15,000 psi. I will
> collapse the spring and THEN some. I can't bring myself to put the
> tension on the blade that would bring the 2.5 mils of displacement on
> the caliper to get the 15,000 psi. Without some more confidence that
> I am going the right way, I am afraid I will break the saw (and I will
> be WAY past collapse of the spring). Can anyone tell me what I am
> doing wrong? Has anyone done this and can tell me what did your
> standard Delta gauge read (with the standard Delta spring) when you
> put 15,000 (or whatever PSI you used)?
>
> By the way, I know about all the different methods, such as the
> flutter test, etc. I am doing this to get a feeling what a standard
> tension is and then I will go my own way, but I would like to at least
> experience what 15,000 psi is.
Some springs are not up to the challenge or have no longer go their original
tension. This could be why yours collapses. More than likely your blade
would break before your saw would.