...just thought I'd throw this into the mix: I have encountered an accuracy
problem having to do with the fence, I think?! Before I go on, it's lined
up fine...fence is perfectly parallel with the blade and blade is at 90
degrees. When I adjust the scale, the machine cuts perfectly up to maybe 10
inches...then my final measurement creeps up to about a 32nd at 36 inches or
so. Huh? This has been a poser for a while and I've learned to check fence
to blade to compensate, but what the heck is going on?
Charlie Groh
My first guess, like the other replies, is a tape measure problem.
But, let's say that doesn't turn out to be the problem. Second guess would
be to check the front rail on your fence. If it has a bow it will affect
accuracy and squareness as you slide the fence along said rail.
--
Bill Pounds
http://www.billpounds.com/woodshop
"Charlie Groh" <[email protected]> wrote in message
news:[email protected]...
> ...just thought I'd throw this into the mix: I have encountered an
accuracy
> problem having to do with the fence, I think?! Before I go on, it's lined
> up fine...fence is perfectly parallel with the blade and blade is at 90
> degrees. When I adjust the scale, the machine cuts perfectly up to maybe
10
> inches...then my final measurement creeps up to about a 32nd at 36 inches
or
> so. Huh? This has been a poser for a while and I've learned to check
fence
> to blade to compensate, but what the heck is going on?
>
> Charlie Groh
>
>
"B a r r y" wrote in message
> Could be, but you've never seen an inaccurate tape?
I don't think I've ever seen an "accurate" one .. just ones that don't read
_precisely_ the same. :)
I do have two Stanley ten footers that _agree_ with my table saw fence to
less than a 64th over 50", as best as I can actually _see_.
I wouldn't trade either for all the Starret's in the world that don't.
--
www.e-woodshop.net
Last update: 4/13/04
On Sat, 1 May 2004 22:35:48 -0700, "Charlie Groh"
<[email protected]> wrote:
>...just thought I'd throw this into the mix: I have encountered an accuracy
>problem having to do with the fence, I think?! Before I go on, it's lined
>up fine...fence is perfectly parallel with the blade and blade is at 90
>degrees. When I adjust the scale, the machine cuts perfectly up to maybe 10
>inches...then my final measurement creeps up to about a 32nd at 36 inches or
>so. Huh? This has been a poser for a while and I've learned to check fence
>to blade to compensate, but what the heck is going on?
>
>Charlie Groh
>
================
First of all MY fence is set up with about 1/32 inch offset at the
back of the fence... BUT I have no problem sawing a 8 foot 1x6 down
to a 1x 3 and having both ends of the finished piece measure 3
inches...
I keep the workpiece firmly against the fence at a point just if front
of the blade itself..I could care less how far the work piece is away
from the fence at the rear.. if everything is dead on parralel like
you say then I think you are not feeding the stock correctly...
On Mon, 3 May 2004 17:07:53 -0500, "Swingman" <[email protected]> wrote:
*"B a r r y" wrote in message
*
*> >... but I'm still trying to figure how a tapered cut (i.e, wider
on one
*end
*> >than the other) could be the result of the tape measure on a table
saw
*> >fence?
*> >
*> >Somebody clue me in.
*>
*> I missed "taper" in the original message.
*
*It wasn't, specifically, but see below.
*
*> I read the trouble description as the piece was 1/32' wider than
*> expected when ripping really wide panels, and dead on when ripping
*> narrower parts.
*>
*> Obviously, I wasn't the only one! <G>
*
*I, mistakenly it seems, read the problem as one where the "cut" got
wider as
*it progressed.
*
*<original quote> When I adjust the scale, the machine cuts perfectly
up to
*maybe 10 inches...then my final measurement creeps up to about a 32nd
at 36
*inches or so.<unquote>
...yup, this wasn't clear guys! So sorry. The cut does not taper,
but if I rip for 6 inches, it's good; if I rip for 30 inches, it's
not...in fact my final cut piece is wider *over all* than indicated on
the fence scale. Heh... cg
*
*-
*www.e-woodshop.net
*Last update: 4/13/04
*
On Mon, 3 May 2004 10:05:52 -0500, "Swingman" <[email protected]> wrote:
>... but I'm still trying to figure how a tapered cut (i.e, wider on one end
>than the other) could be the result of the tape measure on a table saw
>fence?
>
>Somebody clue me in.
I missed "taper" in the original message.
I read the trouble description as the piece was 1/32' wider than
expected when ripping really wide panels, and dead on when ripping
narrower parts.
Obviously, I wasn't the only one! <G>
Barry
On Sun, 02 May 2004 13:54:14 GMT, Unisaw A100 <[email protected]>
wrote:
*B space a space r space r space y
*>Could be, but you've never seen an inaccurate tape?
*
*
*
*Which begs the question, how do you know you have an
*accurate measuring device?
*
*UA100
...good thought. My brother is a machinist and our conversations
about tolerances are, ah, interesting! He thinks in "tenths"
(ten-thousanths of an inch) and I get to 128th on a good day. So,
once upon a time, he gave me a state of the art set of calipers.
Since then, I've made a few mdf and some ply patterns representing
"perfect" measurements. When I need to tune the saw, or any given
measuring device I use, I use these patterns as my bench mark. Works
well, for an old framer anyhow! :O)
Charlie Groh
On Tue, 04 May 2004 04:32:05 GMT, "Greg Millen" <[email protected]>
wrote:
*g'day Mike,
*
*I have to tell you I'm laughing here. Reading the posts so far, I am
*reminded of a scene on tv from ages ago, a policeman is interviewing
a crowd
*and walks away with ten different descriptions, ranging from black,
to asian
*to caucasian. Black hair, red hair, blonde. Too funny!
*
*Anyway, FWIW/IMNSHO/IAGAS, right or wrong, my thinking is this:
*
*Assumptions.
*Tapering is not a factor
*TS is tuned correctly, blade square to fence etc.
*
*Facts.
*1. Charlie Groh (CG) achieves a perfect measured cut on his TS if the
width
*is <= 10".
*2. If CG makes a cut >10", an error of up to + 1/32" is introduced.
*
*
*Opinion.
*There are two potential measurement errors here (this does not
discount some
*other error of course).
*
*1. The measurement on the TS is, in fact, accurate and there is no
problem
*at all. CG may *think* he has a problem with the TS when he
re-measures the
*cut piece with an INNACURATE tape such as I described earlier.
*
*2. There is an error on the TS measurement tape.
*
*Alternatives.
*
*1. Parallax error
*
*2. when tightening the fence for a 10" cut, CG may not be tightening
it as
*hard as he does for a 36" cut. The extra tightening may introduce
error
*(though this is unlikely if he checks the readout post tightening).
*
*3. the fence guide bar may be bent slightly (reaching here).
*
*4. Handling technique used to cut a 10" piece vice a 36" piece is
different
*and introduces an error.
*
*
*For CG.
*
*Charlie, if I were you, I'd start by pulling out every measuring
device I
*own and check them against each other, then against your machine
fence
*scales.
*
*I like this thread, interesting, entertaining and no abuse - so far!
Kinda
*like the old days, well, if you exclude Bleeds and a coupla udders.
...LOL! It *has* been interesting, and I'm sure I'll find the
demon...and will report same under the header, "Powermatic 66 Problem
Goes to Mars!"...thanks, Greg. cg
On Sat, 1 May 2004 22:35:48 -0700, "Charlie Groh" <[email protected]> wrote:
>...just thought I'd throw this into the mix: I have encountered an accuracy
>problem having to do with the fence, I think?! Before I go on, it's lined
>up fine...fence is perfectly parallel with the blade and blade is at 90
>degrees. When I adjust the scale, the machine cuts perfectly up to maybe 10
>inches...then my final measurement creeps up to about a 32nd at 36 inches or
>so. Huh? This has been a poser for a while and I've learned to check fence
>to blade to compensate, but what the heck is going on?
>
>Charlie Groh
>
>
One possibility that hasn't been mentioned yet is parallax; are you looking
straight down on the cursor when you set the fence? 1/32" seems like about
the right amount of error for it to be from parallax.
Bob S
"Charlie Groh" wrote in message
> ...the problem is *not* a tapered cut. At about 10" and below the cut
> piece will measure exactly what the scale reads (using another,
> reliable, measuring device)...at, say, 30" the cut piece will measure
> longer than the scale reads...make sense? cg
IOW, when you rip to the dimensions of 3" wide X 36" long, the resulting
ripped board is indeed 3" wide, from one end to the other, and X 36" on both
sides?
If that is the case, you could have fooled me with the description of the
problem in your original post ... my apologies.
--
www.e-woodshop.net
Last update: 4/13/04
Charlie Groh wrote:
>...just thought I'd throw this into the mix: I have encountered an accuracy
>problem having to do with the fence, I think?! Before I go on, it's lined
>up fine...fence is perfectly parallel with the blade and blade is at 90
>degrees. When I adjust the scale, the machine cuts perfectly up to maybe 10
>inches...then my final measurement creeps up to about a 32nd at 36 inches or
>so. Huh? This has been a poser for a while and I've learned to check fence
>to blade to compensate, but what the heck is going on?
Are you saying your scale (the measuring tape thingy) on the
front rail is off?
If so, how do you know this? What I'm getting at is, are
you cutting using the scale from the saw and then checking
with a hand held tape? If so it could be your tape or it
could be the scale on the saw. You need to determine which
is correct.
UA100
"Mike Marlow" wrote in message
> > Charlie Groh wrote:
> >> and blade is at 90 degrees. When I adjust the scale, the machine
> >> cuts perfectly up to maybe 10 inches...then my final measurement
> >> creeps up to about a 32nd at 36 inches or so. Huh? This has been a
> >> poser for a while and I've learned to check fence to blade to
> >> compensate, but what the heck is going on?
> He said that once he sets it up, it cuts fine on shorter pieces - up to 10
> inces, but wanders on longer pieces. At least that's what I get from his
> description. In that case, I can't see anything but a fence that is not
> holding well and is creeping at the front as the pressure from longer
pieces
> is applied to it. I'd take a hard look at the lock down on the fence.
I'm with you on this Mike. If he is indeed describing, as it certainly
appears, a "tapered cut", that problem is generally caused by a
misalignment, most likely blade and fence, or a fence that is
flexing/moving.
The first thing that I would check, despite what was said about being
"perfectly parallel with the blade", is to see if the back of the fence is
not toed out too far away from the blade.
--
www.e-woodshop.net
Last update: 4/13/04
On Mon, 3 May 2004 15:17:45 -0500, "Swingman" <[email protected]> wrote:
*
*"Charlie Groh" wrote in message
*
*> ...the problem is *not* a tapered cut. At about 10" and below the
cut
*> piece will measure exactly what the scale reads (using another,
*> reliable, measuring device)...at, say, 30" the cut piece will
measure
*> longer than the scale reads...make sense? cg
*
*IOW, when you rip to the dimensions of 3" wide X 36" long, the
resulting
*ripped board is indeed 3" wide, from one end to the other, and X 36"
on both
*sides?
..now were communicating! :O)
*
*If that is the case, you could have fooled me with the description of
the
*problem in your original post ... my apologies.
...no, mine. This condition is a bugbear *to* describe. But, read
the whole thread, if you get a minute, and I *think* it'll come
together. I haven't had time to get out there yet, but I really think
the fence may be creeping. Although, I'll check on most of the
comments I've had on this...good info! cg
On Sun, 02 May 2004 12:33:55 GMT, B a r r y
<[email protected]> wrote:
*On Sun, 02 May 2004 11:56:33 GMT, "Mike Marlow"
*<[email protected]> wrote:
*
*>He said that once he sets it up, it cuts fine on shorter pieces - up
to 10
*>inces, but wanders on longer pieces. At least that's what I get
from his
*>description. In that case, I can't see anything but a fence that is
not
*>holding well and is creeping at the front as the pressure from
longer pieces
*>is applied to it. I'd take a hard look at the lock down on the
fence.
*
*Could be, but you've never seen an inaccurate tape?
*
*Barry
...these are good replys, you guys. The info I gave does allow for
your hypothesis, Barry, although I've had the saw for 10 years and
this problem has cropped-up in the last year or so...the tape is fine,
as is the tape I make my final measurements with. I think you have a
good idea, Mike, and I'll really check out the fence. Thanks for the
help, gentlemen! cg
On Sun, 02 May 2004 11:56:33 GMT, "Mike Marlow"
<[email protected]> wrote:
>He said that once he sets it up, it cuts fine on shorter pieces - up to 10
>inces, but wanders on longer pieces. At least that's what I get from his
>description. In that case, I can't see anything but a fence that is not
>holding well and is creeping at the front as the pressure from longer pieces
>is applied to it. I'd take a hard look at the lock down on the fence.
Could be, but you've never seen an inaccurate tape?
Barry
g'day Mike,
I have to tell you I'm laughing here. Reading the posts so far, I am
reminded of a scene on tv from ages ago, a policeman is interviewing a crowd
and walks away with ten different descriptions, ranging from black, to asian
to caucasian. Black hair, red hair, blonde. Too funny!
Anyway, FWIW/IMNSHO/IAGAS, right or wrong, my thinking is this:
Assumptions.
Tapering is not a factor
TS is tuned correctly, blade square to fence etc.
Facts.
1. Charlie Groh (CG) achieves a perfect measured cut on his TS if the width
is <= 10".
2. If CG makes a cut >10", an error of up to + 1/32" is introduced.
Opinion.
There are two potential measurement errors here (this does not discount some
other error of course).
1. The measurement on the TS is, in fact, accurate and there is no problem
at all. CG may *think* he has a problem with the TS when he re-measures the
cut piece with an INNACURATE tape such as I described earlier.
2. There is an error on the TS measurement tape.
Alternatives.
1. Parallax error
2. when tightening the fence for a 10" cut, CG may not be tightening it as
hard as he does for a 36" cut. The extra tightening may introduce error
(though this is unlikely if he checks the readout post tightening).
3. the fence guide bar may be bent slightly (reaching here).
4. Handling technique used to cut a 10" piece vice a 36" piece is different
and introduces an error.
For CG.
Charlie, if I were you, I'd start by pulling out every measuring device I
own and check them against each other, then against your machine fence
scales.
I like this thread, interesting, entertaining and no abuse - so far! Kinda
like the old days, well, if you exclude Bleeds and a coupla udders.
--
Greg
"Mike Marlow" wrote in message ...
<snip>
> So - what if you lay your tape measure out along the rip fence scale - I'm
> guessing they do not read the same. Can't understand how they could and
you
> end up with the problem you face. Bad scale? Maybe this is what some of
> the earlier posters were referring to and I misunderstood their point. A
> mind is a terrible thing to lose...
> --
>
> -Mike-
> [email protected]
>
>
Could it be the way the blade is shrpened ? Does it do that with
other blades. Maybe the blade is pulling the piece away from the
fence ?
"Charlie Groh" <[email protected]> wrote in message news:<[email protected]>...
> ...just thought I'd throw this into the mix: I have encountered an accuracy
> problem having to do with the fence, I think?! Before I go on, it's lined
> up fine...fence is perfectly parallel with the blade and blade is at 90
> degrees. When I adjust the scale, the machine cuts perfectly up to maybe 10
> inches...then my final measurement creeps up to about a 32nd at 36 inches or
> so. Huh? This has been a poser for a while and I've learned to check fence
> to blade to compensate, but what the heck is going on?
>
> Charlie Groh
B a r r y wrote:
> On Tue, 4 May 2004 09:07:07 -0500, "Swingman" <[email protected]> wrote:
>
>
>> Now coming to a silent film theatre near you: "The Keystone Kops
>> meet the wREC Wooddorkers."
>
> And every single one of us knows THE answer!
>
Hell, I don't. I'm thoroughly confused now. Which way to the shop?
--
-Mike-
[email protected]
"B a r r y" wrote in message
> >... but I'm still trying to figure how a tapered cut (i.e, wider on one
end
> >than the other) could be the result of the tape measure on a table saw
> >fence?
> >
> >Somebody clue me in.
>
> I missed "taper" in the original message.
It wasn't, specifically, but see below.
> I read the trouble description as the piece was 1/32' wider than
> expected when ripping really wide panels, and dead on when ripping
> narrower parts.
>
> Obviously, I wasn't the only one! <G>
I, mistakenly it seems, read the problem as one where the "cut" got wider as
it progressed.
<original quote> When I adjust the scale, the machine cuts perfectly up to
maybe 10 inches...then my final measurement creeps up to about a 32nd at 36
inches or so.<unquote>
-
www.e-woodshop.net
Last update: 4/13/04
Greg Millen wrote:
> "Mike Marlow" wrote in message ...
>> I'd bet you've got the most likely suggestion Charlie. It can't be
>> his tape or paralax as others have suggested or he would never have
>> gotten accurate cuts on shorter pieces.
>
> Mike, it is very possible for this to happen. As I alluded to
> earlier, a poorly made tape caused a number of problems for me when
> (IIRC) I used it to measure below 500mm. Although the distance from 0
> to 500 was accurate, the markings in between were wrong. They started
> off tight, then got further apart up to the 500 mark. After that the
> tape was accurate.
>
> It is easy for me to imagine the reverse being true in the OPs case.
OK Greg - I can accept that. Wierd, but I can accept it. I'd sure like to
believe you experienced an anomoly...
--
-Mike-
[email protected]
"Greg Millen" wrote in message
> g'day Mike,
>
> I have to tell you I'm laughing here. Reading the posts so far, I am
> reminded of a scene on tv from ages ago, a policeman is interviewing a
crowd
> and walks away with ten different descriptions, ranging from black, to
asian
> to caucasian. Black hair, red hair, blonde. Too funny!
Now coming to a silent film theatre near you: "The Keystone Kops meet the
wREC Wooddorkers."
--
www.e-woodshop.net
Last update: 4/13/04
Charlie Groh wrote:
>
> ...the problem is *not* a tapered cut. At about 10" and below the cut
> piece will measure exactly what the scale reads (using another,
> reliable, measuring device)...at, say, 30" the cut piece will measure
> longer than the scale reads...make sense? cg
OK - time to refresh my aging mind... You are using the term "scale" to
refer to the rip fence's built in scale? If so - sorry, I got cornfused in
the beginning.
So - what if you lay your tape measure out along the rip fence scale - I'm
guessing they do not read the same. Can't understand how they could and you
end up with the problem you face. Bad scale? Maybe this is what some of
the earlier posters were referring to and I misunderstood their point. A
mind is a terrible thing to lose...
--
-Mike-
[email protected]
Check the set screws that set the fence to blade parallelism. Mine went
south a few weeks ago and the fence would go out of parallel. I used
locktite 241 to keep them in place. You can break the screw out of the 241
if necessary in the future. The factory screws are nyloks and won't last
forever.
Ed Angell
"Swingman" <[email protected]> wrote in message
news:[email protected]...
> "Mike Marlow" wrote in message
>
> > > Charlie Groh wrote:
>
> > >> and blade is at 90 degrees. When I adjust the scale, the machine
> > >> cuts perfectly up to maybe 10 inches...then my final measurement
> > >> creeps up to about a 32nd at 36 inches or so. Huh? This has been a
> > >> poser for a while and I've learned to check fence to blade to
> > >> compensate, but what the heck is going on?
>
> > He said that once he sets it up, it cuts fine on shorter pieces - up to
10
> > inces, but wanders on longer pieces. At least that's what I get from
his
> > description. In that case, I can't see anything but a fence that is not
> > holding well and is creeping at the front as the pressure from longer
> pieces
> > is applied to it. I'd take a hard look at the lock down on the fence.
>
> I'm with you on this Mike. If he is indeed describing, as it certainly
> appears, a "tapered cut", that problem is generally caused by a
> misalignment, most likely blade and fence, or a fence that is
> flexing/moving.
>
> The first thing that I would check, despite what was said about being
> "perfectly parallel with the blade", is to see if the back of the fence is
> not toed out too far away from the blade.
>
> --
> www.e-woodshop.net
> Last update: 4/13/04
>
>
>
>
>
>
>
"B a r r y" <[email protected]> wrote in message
news:[email protected]...
>
>
> I think we should all apply at NASA. <G>
Hell, I was thinking Secretary of Education.
--
www.e-woodshop.net
Last update: 4/13/04
"Bob G." wrote in message
> First of all MY fence is set up with about 1/32 inch offset at the
> back of the fence... BUT I have no problem sawing a 8 foot 1x6 down
> to a 1x 3 and having both ends of the finished piece measure 3
> inches...
Just a case in point.
I recently bought a Unit-T-Fence to go on my UniFence. Since it is
supposedly a slide-on replacement, I didn't bother to initially check the
alignment when I "slid" it on.
When I did, I found the toe-out at the bottom rear of this fence replacement
to be almost 3/32" ... that's about five times the recommended 1/64th
toe-out for those who subscribe to the theory.
Hell of it is, the cuts are, like yours, absolutely dead-on consistent from
one end to the other.
While I am aware of the obvious departure from normal, I have chosen to
ignore it since I firmly believe that whatever gets the results you want is
obviously correct for that particular situation.
(One of the reasons I am not too worried about it is that the strip of UHMW
could well be worn at that particular spot, or is inconsistent in thickness
throughout the length of the fence ... it's not like I am dealing with
metal.)
--
www.e-woodshop.net
Last update: 4/13/04
Unisaw A100 wrote:
> Charlie Groh wrote:
>> ...just thought I'd throw this into the mix: I have encountered an
>> accuracy problem having to do with the fence, I think?! Before I go
>> on, it's lined up fine...fence is perfectly parallel with the blade
>> and blade is at 90 degrees. When I adjust the scale, the machine
>> cuts perfectly up to maybe 10 inches...then my final measurement
>> creeps up to about a 32nd at 36 inches or so. Huh? This has been a
>> poser for a while and I've learned to check fence to blade to
>> compensate, but what the heck is going on?
>
>
>
> Are you saying your scale (the measuring tape thingy) on the
> front rail is off?
>
> If so, how do you know this? What I'm getting at is, are
> you cutting using the scale from the saw and then checking
> with a hand held tape? If so it could be your tape or it
> could be the scale on the saw. You need to determine which
> is correct.
>
> UA100
He said that once he sets it up, it cuts fine on shorter pieces - up to 10
inces, but wanders on longer pieces. At least that's what I get from his
description. In that case, I can't see anything but a fence that is not
holding well and is creeping at the front as the pressure from longer pieces
is applied to it. I'd take a hard look at the lock down on the fence.
--
-Mike-
[email protected]
In article <[email protected]>,
[email protected] wrote:
If I had a problem resembling this on a band saw I would blame the blade
or the tension. Is there any possibility that your blade has some
damage that causes it to "pull" to one side? You might test this idea
with a different blade -- assuming that the problem is reproducable.
Dick
> ...these are good replys, you guys. The info I gave does allow for
> your hypothesis, Barry, although I've had the saw for 10 years and
> this problem has cropped-up in the last year or so...the tape is fine,
> as is the tape I make my final measurements with. I think you have a
> good idea, Mike, and I'll really check out the fence. Thanks for the
> help, gentlemen! cg
Charlie,
Barry and Keith are likely correct, a while ago I had a problem with a tape
that had a slight logarithmic progression on it. It drove me nuts until I
discovered the error. Check the tape.
--
Greg
"Charlie Groh" <[email protected]> wrote in message
news:[email protected]...
> ...just thought I'd throw this into the mix: I have encountered an
accuracy
> problem having to do with the fence, I think?! Before I go on, it's lined
> up fine...fence is perfectly parallel with the blade and blade is at 90
> degrees. When I adjust the scale, the machine cuts perfectly up to maybe
10
> inches...then my final measurement creeps up to about a 32nd at 36 inches
or
> so. Huh? This has been a poser for a while and I've learned to check
fence
> to blade to compensate, but what the heck is going on?
>
> Charlie Groh
>
>
On Sun, 02 May 2004 21:56:31 GMT, "Mike Marlow"
<[email protected]> wrote:
*Charlie Campney wrote:
*> Could it be the way the blade is shrpened ? Does it do that with
*> other blades. Maybe the blade is pulling the piece away from the
*> fence ?
*>
*
*I'd bet you've got the most likely suggestion Charlie. It can't be
his tape
*or paralax as others have suggested or he would never have gotten
accurate
*cuts on shorter pieces. If I understand him correctly, he's seeing a
run on
*longer pieces and a blade that is too thin (thin kerf) or one
improperly
*sharpened seem like they could well be the culprit. This has
captured my
*interest - have to mark this thread as one to follow.
...yeah, this *is* an interesting thread, and all the different
problems/solutions have been viable. However (heh), the blade idea
doesn't apply as I have three *very* good blades (a Forest and a
Tenyru Gold Medal, which is my favorite, and a Tenyru melemine
blade)...the condition persists with all of them. I send my Forest to
Forest to be sharpened, and recently I had the pleasure to try
Accurate Cut Carbide Inc., in Utah, for my Tenryu...they're real good,
folks, you should check out the DVD disc they promo their shop
with...sweet operation. BTW, none of these blades are "thin kerf"...I
am not a big fan of thin kerf, unless it's on my 6 1/2 Milwaukee trim
saw.
Charlie Groh
Charlie Campney wrote:
> Could it be the way the blade is shrpened ? Does it do that with
> other blades. Maybe the blade is pulling the piece away from the
> fence ?
>
I'd bet you've got the most likely suggestion Charlie. It can't be his tape
or paralax as others have suggested or he would never have gotten accurate
cuts on shorter pieces. If I understand him correctly, he's seeing a run on
longer pieces and a blade that is too thin (thin kerf) or one improperly
sharpened seem like they could well be the culprit. This has captured my
interest - have to mark this thread as one to follow.
--
-Mike-
[email protected]
"Mike Marlow" wrote in message
> OK Greg - I can accept that. Wierd, but I can accept it. I'd sure like
to
> believe you experienced an anomoly...
... but I'm still trying to figure how a tapered cut (i.e, wider on one end
than the other) could be the result of the tape measure on a table saw
fence?
Somebody clue me in.
--
www.e-woodshop.net
Last update: 4/13/04
On 02 May 2004 16:24:04 EDT, [email protected] (Bob
Summers) wrote:
*On Sat, 1 May 2004 22:35:48 -0700, "Charlie Groh"
<[email protected]> wrote:
*
*>...just thought I'd throw this into the mix: I have encountered an
accuracy
*>problem having to do with the fence, I think?! Before I go on, it's
lined
*>up fine...fence is perfectly parallel with the blade and blade is at
90
*>degrees. When I adjust the scale, the machine cuts perfectly up to
maybe 10
*>inches...then my final measurement creeps up to about a 32nd at 36
inches or
*>so. Huh? This has been a poser for a while and I've learned to
check fence
*>to blade to compensate, but what the heck is going on?
*>
*>Charlie Groh
*>
*>
*One possibility that hasn't been mentioned yet is parallax; are you
looking
*straight down on the cursor when you set the fence? 1/32" seems like
about
*the right amount of error for it to be from parallax.
*
*Bob S
...true, but I've messed around with that alot since learning about
the "cheek weld" in army marksman training; in order to hit the
target the same every time, you need for your eye to be in the same
place relative to the sights every time. See? Same goes for anything
re. accuracy vis-a-vis the position of your eyeball. A toughy for
sure when looking down at a hair line and a scale. So, yeah, I've
taken this factor into account. Another friend of mine mentioned the
rail, but that's out also, as I'm the only person to operate my
machine and would know about all the knocks and stuff. But in that
discussion the nylon "keepers" attached to the fence were mentioned
(this guy runs the cabinet shop for Universal Studios, the park, out
here and they have great equipment...but he deals with a lot of others
using it...you get the idea, heh.) so *that* got me to thinkin'...like
I said, the machine is 10 years old and I haven't been so easy on it,
either. I'll go through it this week and give you guys an update. cg
On Tue, 4 May 2004 09:07:07 -0500, "Swingman" <[email protected]> wrote:
>Now coming to a silent film theatre near you: "The Keystone Kops meet the
>wREC Wooddorkers."
And every single one of us knows THE answer!
Barry
On Sat, 1 May 2004 22:35:48 -0700, "Charlie Groh"
<[email protected]> wrote:
> When I adjust the scale, the machine cuts perfectly up to maybe 10
>inches...then my final measurement creeps up to about a 32nd at 36 inches or
>so. Huh? This has been a poser for a while and I've learned to check fence
>to blade to compensate, but what the heck is going on?
Either the tape on the scale, or the tape your using to measure the
cut part, or both, are off
Barry.
On Sun, 02 May 2004 13:54:14 GMT, Unisaw A100 <[email protected]>
wrote:
>Which begs the question, how do you know you have an
>accurate measuring device?
Some sort of standard.
My standard is my ts fence rail, as it's the hardest measuring device
in the shop to change. <G> I have a few tapes that agree with it,
but stick with one throughout a project. My favorite is a 16' "center
finding" tape I bought from Lee Valley.
I have no idea if any of them are truly accurate beyond my needs.
Barry
On Mon, 3 May 2004 10:05:52 -0500, "Swingman" <[email protected]> wrote:
*
*"Mike Marlow" wrote in message
*
*> OK Greg - I can accept that. Wierd, but I can accept it. I'd sure
like
*to
*> believe you experienced an anomoly...
*
*... but I'm still trying to figure how a tapered cut (i.e, wider on
one end
*than the other) could be the result of the tape measure on a table
saw
*fence?
*
*Somebody clue me in.
...the problem is *not* a tapered cut. At about 10" and below the cut
piece will measure exactly what the scale reads (using another,
reliable, measuring device)...at, say, 30" the cut piece will measure
longer than the scale reads...make sense? cg
"Mike Marlow" wrote in message ...
> I'd bet you've got the most likely suggestion Charlie. It can't be his
tape
> or paralax as others have suggested or he would never have gotten accurate
> cuts on shorter pieces.
Mike, it is very possible for this to happen. As I alluded to earlier, a
poorly made tape caused a number of problems for me when (IIRC) I used it to
measure below 500mm. Although the distance from 0 to 500 was accurate, the
markings in between were wrong. They started off tight, then got further
apart up to the 500 mark. After that the tape was accurate.
It is easy for me to imagine the reverse being true in the OPs case.
Referenced previous thread can be found at:
http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&oe=UTF-8&c2coff=1&threadm=JK5T5.4%24zS.4768%40news0.optus.net.au&rnum=1&prev=/groups%3Fas_q%3Dtape%26safe%3Dimages%26ie%3DUTF-8%26oe%3DUTF-8%26as_ugroup%3Drec.woodworking%26as_uauthors%3DGreg%2520millen%2520%26lr%3D%26hl%3Den
cheers,
Greg