Delta Band saw won't cut straight
Jonah Peskin
I've replaced the blade several times and this does not help. I've tried using
thicker blades for a straighter cut (up to 1/2''), but this doesn't help
either.
What happens is I begin the cut and as I progress, holding the wood as firmly
as humanly possible, the blade inches it's way over to the side. Note that I
do not let the wood move so what happens is the blade must bend to continue
moving over.
The only way I can get a straight cut is by angling my wood at about _10_
degrees or more to allow the blade to follow it's crooked path while remaining
on my marked cutting path.
Is this a universal band saw error? Should I go get a table saw for straight
cuts? Is there something I can adjust to fix the problem?
I'd appreciate any info, by net-news post or by e-mail, concerning solutions to
this problem or concerning another info. source that would help.
Thanks in advance,
JP
Jonah Peskin
jpe...@wpi.wpi.edu
Will Self
>The only way I can get a straight cut is by angling my wood at about _10_
>degrees or more to allow the blade to follow it's crooked path while remaining
>on my marked cutting path.
This is exactly right. Pat yourself on the back for having developed the
technique. Each blade will have its own "drift", so you'll need to know
the angle for each blade. Then you can clamp a board on the bandsaw table
at the approriate angle and have a fence. By the way, Vise-Grip C-clamps
are sure great for this and many other uses.
Will Self
"Ask for Vise-Grip C-clamps for Christmas"
131A50000-FarwellC(DR7383)299
|> I've got a Delta, 3-wheel, 16'', 1/2h.p. band saw that _will not_ cut straight.
|> What happens is I begin the cut and as I progress, holding the wood as firmly
|> as humanly possible, the blade inches it's way over to the side. Note that I
|> do not let the wood move so what happens is the blade must bend to continue
|> moving over.
|>
I have the same saw, and the same symptoms. However, I believe this to
be the nature of all band saws, not just this one (although I imagine
it's not as noticeable on some others).
|> The only way I can get a straight cut is by angling my wood at about _10_
|> degrees or more to allow the blade to follow it's crooked path while remaining
|> on my marked cutting path.
That is exactly what you are supposed to do; and the reason for the
adjustment nuts on the fence. It's pretty easy to get close this way,
but still not as good as a table saw. The bottom line: band saws are
made to cut curves, not straight lines.
|>
|> Is this a universal band saw error?
No, it's a universal band saw feature ;-)
|> Should I go get a table saw for straight
|> cuts?
Yes.
|>
|> Jonah Peskin
|> jpe...@wpi.wpi.edu
Bennett Leeds
> In article <2un0ov$o...@bigboote.WPI.EDU>, jpe...@wpi.WPI.EDU (Jonah Peskin)
writes:
> |> I've got a Delta, 3-wheel, 16'', 1/2h.p. band saw that _will not_ cut
> |> straight.
>
> be the nature of all band saws, not just this one (although I imagine
> it's not as noticeable on some others).
This did not happen with my 3 wheel Inca bandsaw.
> |> The only way I can get a straight cut is by angling my wood at about _10_
> |> degrees or more ....
>
> That is exactly what you are supposed to do;...
> The bottom line: band saws are made to cut curves, not straight lines.
I disagree with that bottom line. Many bandsaws are built to do some amount
of resawing, which means cutting in a straight line.
> |> Is this a universal band saw error?
>
> No, it's a universal band saw feature ;-)
Again, it wasn't a "feature" of my old saw. However, that saw had flat
wheels, which I believe not only give better wide blade support, they
also help keep the blade aligned. While I had other problems with this
bandsaw, cutting straight and non-angled was never a problem.
- Bennett Leeds
ben...@mv.us.adobe.com
Just say Tensioning and tracking were another story altogether.
Donald L. Snyder
This method for getting straight rip cuts is discussed in various books.
Examples:
Mark Duginske, Band Saw Basics, pages 94-95
Delta Machinery Corp., Getting the Most Out of Your Band Saw, page 33
The suggestions I've seen are to mark a rip line on a scrap board,
start cutting moving the board as necessary to follow the line,
stop the saw with the board in place partially cut, clamp a fence
along the board keeping its angle relative to the table of the saw.
Another approach is to place a guide near the front of the blade
that is a single pivot point. Advance the board to be cut using
the pivot point to keep the saw kerf aligned with the cut line, cut
slightly wide of the intended cut line, then hand plane to finish
up.
Ole-Hjalmar Kristensen TF.DT/DELAB
You must be joking. I have a cheap Taiwan 3-wheel bandsaw, and even this one will
cut straight. If the blade is OK, and centered on the wheels, you should be able
to cut to the fence. Unless you use too much force, and the blade bends, of
course.
Clifford Baron
>Jonah wrote:
>>The only way I can get a straight cut is by angling my wood at about _10_
>>degrees or more to allow the blade to follow it's crooked path while
remaining
>>on my marked cutting path.
>This is exactly right. Pat yourself on the back for having developed the
>technique. Each blade will have its own "drift", so you'll need to know
>the angle for each blade. Then you can clamp a board on the bandsaw table
>at the approriate angle and have a fence.
Just a bit of clarification here. As Will suggests, "drift" is endemic to
many bandsaw designs. However, certain (and I hazard to say, "better") band
saws (Delta 14", Inca 340, General, others) cut with no detectable drift once
properly adjusted. In my experience drift is a function mostly of blade
tension (use the maximum recommended tension for your blade), the fit of the
guide blocks to the blade (use Cool Blocks or custom-fit chunks of lignum
vitae set VERY close to the blade) and the proximity of the guides to the
work (set the upper guide 1/2 - 3/4" from the work; most bandsaws don't allow
the lower guide to be raised and lowered, so get a saw that has the guide
close to the bottom of the table).
IMO, cutting even simple joinery on a band saw that drifts is an exercise in
frustration. Precise alignment and positioning of a C-clamped "fence", while
not impossible, is tedious at best. If you find that your Delta 3 wheeler is
not up to the task after thorough adjustment, and you still wish to remedy
the problem, consider another saw.
-Clifford Baron
Gary Straub
correct that a good saw will not allow the blade to wander. Drift is
caused by the set on the teeth of the blade being irregularor more to one
side than another. What happens is that the blade wants to cut best at an
angle different than 90o. To check for this take a square board and draw
a parallel line some where in the middle of the board. Cut about halfway
through freehand and then stop and hold th board exactly where it stops.
Check the side of the board and you will probably find that it is not 90o
to the table. If you make a fence and clamp it at this same angle the
blade will perform better. But most blades will cut well with the fence a
90o but with some unwanted friction which can cause a few minor problems.
Enjoy!
Gary Straub
gst...@bigcat.missouri.edu
Columbia, MO
Clifford Baron
Gary,
I appreciate your advice, Gary. However, I can assure that I am talking about
drift, not wandering. I defer to your interpretation of the causes of drift
(uneven tooth set), but it occurs to me that another possible cause is uneven
tension across the width of the blade, possibly caused by tires that are not
flat. I raise this possibility because my tires ARE flat, and I get no
detectable drift with any of three different blades that I commonly use (2
1/4" blades, and one 1/2"). OTOH, perhaps I'm just very lucky with the blades
I've bought!
I'm sure there are other possible causes as well.
Good luck to the original poster. I do believe the poor guy just wanted a
reliable way to cut to a straight line!
-Clifford Baron
Christopher J. Shaker
> drift, not wandering. I defer to your interpretation of the causes of drift
> (uneven tooth set), but it occurs to me that another possible cause is uneven
> tension across the width of the blade, possibly caused by tires that are not
> flat.
This statement above really surprises me, because I thought that all bandsaw
tires were crowned to help keep the blade centered on the wheel. I know that
they are crowned on my 14" Delta bandsaw.
Maybe you are describing wheels that have an even thickness around the
wheel? Is that what you mean by 'flat'?
I don't seem to have much drift on my saw, with the 1/4" Delta blade that I
use on it.
Chris
Michael Turski
(snip)
>properly adjusted. In my experience drift is a function mostly of blade
>tension (use the maximum recommended tension for your blade), the fit of the
(snip)
>-Clifford Baron
A more conservative approach is to use just enough tension to eliminate
tracking problems. This way you get longer life out of your blades and
reduce stress on your machine. In my experience, the tension adjustment
is one of the easiest things to experiment with on a bandsaw.
Michael Turski tur...@hqs.mid.gmeds.com
The more careless that I am, the smaller my projects become ;-)
(My opinions are just that)
Glenn Phillips
>>The only way I can get a straight cut is by angling my wood at about _10_
>>degrees or more to allow the blade to follow it's crooked path while remaining
>>>on my marked cutting path.
>
>tension (use the maximum recommended tension for your blade), the fit of the
>guide blocks to the blade (use Cool Blocks or custom-fit chunks of lignum
>vitae set VERY close to the blade) and the proximity of the guides to the
>work (set the upper guide 1/2 - 3/4" from the work; most bandsaws don't allow
>the lower guide to be raised and lowered, so get a saw that has the guide
>close to the bottom of the table).
>
As Cliff has mentioned, there are several factors that could be causing your
problem. A good tuning sounds like what is needed. I did a tune up on my Delta
14" when I bought it used (before I tried cutting any wood). I used Mark
Duginske's (sp) book Bandsaw Basics or Bandsaw Handbook to tune it. I highly
suggest tuning it. I had a friend with a Craftsman 3 wheel who had problems
until he did a tune up on it.
Other things to consider, in addition to Cliff's, are if the wheels are balanced,
the tires (rubber) are in good condition, and the adjustment for the back guide of
the blade (the ball bearing wheel behind the blade to keep it from running off
the tire).
Glenn
Chris Knoell -- BCSS
Jonah, I have the delta 3 wheel 16", and it does exactly the
same thing. Will Self hit the nail on the head, different
blades drift with a mind of their own. Kinda stinks though
that they provide a rip fence with this bandsaw, really doesnt
help much for ripping if the blade isn't always square to the
fence. Good luck. Chris
---
(o o)
------ooO-(_)-Ooo------
Clifford Baron
>I thought that all bandsaw
>tires were crowned to help keep the blade centered on the wheel. I know that
>they are crowned on my 14" Delta bandsaw.
>Maybe you are describing wheels that have an even thickness around the
>wheel? Is that what you mean by 'flat'?
Definitely not. Some wheels are crowned, as you say, to allow the blade to be
centered on the wheel. Crowned wheels are sometimes preferred for carrying
narrower (<1/4") blades. However, when carrying wider blades, a crowned wheel
would necessarily result (it seems to me) in uneven tension through the width
of the blade. Flat wheels, which carry the blade on the outer edge of the
wheel and evenly support the entire width of the blade, would, I think,
minimize this effect.
This is all just armchair hypothesizing, of course. Someone with both crowned
and flat tire machines (counts me out), could test some of these hypotheses.
Those of you with crowned tires, do you get more or less drift with wider
blades?
-Clifford Baron
kar...@austin.ibm.com
: In article AA0...@viking.emcmt.edu, Will Self <ws...@VIKING.EMCMT.EDU> () writes:
: >Jonah wrote:
: >
: >>The only way I can get a straight cut is by angling my wood at about _10_
: >>degrees or more to allow the blade to follow it's crooked path while remaining
: >>on my marked cutting path.
: >
: >This is exactly right. Pat yourself on the back for having developed the
: >technique. Each blade will have its own "drift", so you'll need to know
: >the angle for each blade. Then you can clamp a board on the bandsaw table
: >at the approriate angle and have a fence. By the way, Vise-Grip C-clamps
: >are sure great for this and many other uses.
: >
: >Will Self
: >"Ask for Vise-Grip C-clamps for Christmas"
: Jonah, I have the delta 3 wheel 16", and it does exactly the
: same thing. Will Self hit the nail on the head, different
: blades drift with a mind of their own. Kinda stinks though
I have found out that wide blades tend to drift more.
Consequently, when resawing or ripping, I choose a very thin
blade with agressive teeth set. Unbelievable how well this
works. As to why this happens, it guess it's a combination
of uneven set and friction of the blade with the stock.
BTW, I have tried several blades in the past and I have found
this *ALWAYS* to be the case. I would NEVER consider
resawing on a bandsaw with a wide fine-toothed blade.
Resaw coarse but straight and then plane/joint as needed.
Hope this helps.
: that they provide a rip fence with this bandsaw, really doesnt
: help much for ripping if the blade isn't always square to the
: fence. Good luck. Chris
: ---
: (o o)
: ------ooO-(_)-Ooo------
--
DISCLAIMER: The opinions expressed in this posting are mine
solely and do not represent my employer in any way.
Frank Karner AIX Technical Support | kar...@austin.vnet.ibm.com
kar...@austin.ibm.com
: Chris <csh...@SHAKER-BSD.CISCO.COM> wrote:
I disagree with the notion that the tires have anything to do
with the problem that Jonah has described. At most, it will
impact the front/back angle of the blade to the stock, and
NOT the left/right sides relative to the fence.
If I understand the problem described, the condition is akin to
"creeping". The blade enters the stock straight at first, but
then the bottom and top of the blade on the stock end up at
DIFFERENT distances from the fence. Yes, at one point, the
tensions equalize and you continue to rip at the crooked angle,
but what about the beginning of the cut? It started out
straight, as intended, but then progressively changed until it
settled at a stable angle. This is definitely unacceptable, in
my opinion.
As I pointed out in a previous post, defeat this unwanted
behavior by using a thin, fairly coarse blade with aggressive
set, and by all means, adjust the tension properly.
: -Clifford Baron
Paul Houtz
>
>Just a bit of clarification here. As Will suggests, "drift" is endemic to
>many bandsaw designs. However, certain (and I hazard to say, "better") band
>saws (Delta 14", Inca 340, General, others) cut with no detectable drift once
>tension (use the maximum recommended tension for your blade), the fit of the
>guide blocks to the blade (use Cool Blocks or custom-fit chunks of lignum
>vitae set VERY close to the blade) and the proximity of the guides to the
>work (set the upper guide 1/2 - 3/4" from the work; most bandsaws don't allow
>the lower guide to be raised and lowered, so get a saw that has the guide
>close to the bottom of the table).
Actually, I disagree with this, slightly.
I have the Delta 14" bandsaw, and I have a Starret 3/4" 3 tpi hook-tooth
blade mounted on it, and it leads very slightly. I can adjust the rip
fence to it, so it is not horrible, but it is definitely there.
I always mount and track my blades the same way, using the co-planar
method. I have not been able to force this blade to cut parallel to
the itself no matter what I do with the guides. Especially when resawing,
the only way I get the kind of results I demand (such as the ability to
cut 1/64" veneers) is to allow for the blade's natural lead. Changing
the blade tension does not appear to affect the lead at all. By
rotating the saw table on it's trunions, the cut is now parallel to the
miter guage, so I can almost use this machine like a tablesaw.
I believe this lead is not due to the bandsaw, nor the tracking, but
rather the blade.
I have also run an Olsen 1/2" 3 tpi blade on this machine. It leads
quite a bit more than the Starret blade. I cannot adjust the fence
such that I can rip against the fence with the Olsen blade.
I have also run the stock Delta blade that came with this saw. I believe
it was a 8 TPI hook-tooth 1/4" blade. It leads in the opposite
direction from the Starret and Olsen blades, and wanders, too. Increasing
the tension on this blade tends to reduce the wander, but has no affect
on the lead.
I have come to the conclusion that the lead is caused by (in order):
1. The set and sharpness of the teeth.
2. The quality and width of the blade.
3. The technique used in tracking the blade (if the co-planar
method is used, lead seems reduced significantly to me).
4. The alignment of the bandsaw (if the wheels are not properly
aligned, some lead can be eliminated by aligning them.).
5. The design of the saw (Some people have reported that flat-wheeled
saws produce less lead than crowned wheeled saws).
6. The quality of the bandsaw and it's design (three-wheeled don't
seem to cut as straight as two wheel in some situations).
IMHO.
Paul Houtz
>>Gary Straub writes:
>>Clifford, I think you are confusing drift with blade wandering. You are
>
>Gary,
>
>I appreciate your advice, Gary. However, I can assure that I am talking about
>drift, not wandering. I defer to your interpretation of the causes of drift
>(uneven tooth set), but it occurs to me that another possible cause is uneven
>tension across the width of the blade, possibly caused by tires that are not
>flat. I raise this possibility because my tires ARE flat, and I get no
>detectable drift with any of three different blades that I commonly use (2
>1/4" blades, and one 1/2"). OTOH, perhaps I'm just very lucky with the blades
>I've bought!
Actually, uneven tension across the width of the blade can cause
vibration, which affects the quality of cut, but is not the cause
of wander.
I had a bandsaw with perfectly even blade tension and no vibration, and
perfectly uniform tires, and it wandered like hell.
I believe wander is exacerbated by wheels that are not coplanar. When
the tracking adjustment is used to force the blade onto the middle of
the tire due to poor alignment of the wheels, then I believe wander
increases. A clue to this is that the blade tracks at a different
place on the upper wheel than the lower wheel. Three-wheel bandsaws
mystify me, so I do not apply this to them.
Also, on a given machine, some blades wander and some don't. Quality
of the blade seems definitly to be a factor.
csh...@shaker-bsd.cisco.com (Christopher J. Shaker) writes:
>This statement above really surprises me, because I thought that all bandsaw
>tires were crowned to help keep the blade centered on the wheel. I know that
>they are crowned on my 14" Delta bandsaw.
I believe the Inca bandsaws, and many other european made bandsaws
have flat, rather than crowned wheels. Crowned wheels help hold the
blade on the saw, but crowning is not necessary to do so. Co-planar
wheels will also track a blade well, and crowning is not necessary.
In fact, crowning is probably not the best way to go for a bandsaw, because
the crown does not support the blade throughout its width. It probably
adds to wander and lead problems slightly.