Bandsaw wheel crown "controversy"
M.A. Martin
This posting is prompted by a bandsaw I recently obtained for
restoration: a 14" Walker Turner unit. BTW - thanks to all who have
provided helpful information on the saw so far!
This saw has a "flat" surface on the wheel. Most current saws (such as
the Delta units) have a "crowned" surface which causes the blade to
track in the center. The advantage of this is more stable tracking.
The disadvantages are that less of the blade surface is in contact with
the wheel, and this can be a problem with wide blades.
In the latest FWW, Robert Vaugh wrote an article on fine tuning
bandsaws. He states rather dogmatically in a picture caption that
"Tires need a crowned surface"...."to track accurately and smoothly".
He also gives a reference (FWW #95) for crowning the saw yourself. He
doesn't recognize the existance of flat wheels. This leaves one with
the impression that flat wheels should be crowned whenever you come
across one.
In Mark Duginske's Bandswaw Handbook, there is a lot of information on
both crowned and flat wheels. Duginske states that "The crowned wheel
is popular in America for use on consumer-grade band saws, and is usd on
the Sears, Delta, and Taiwanese models. The flat-wheeled design is
often used on larger Industrial saws and some European machines [such as
the Inca]". He then goes on to say that the crown is used because it
makes tracking very easy, whereas the flat wheel takes a little
practice, but it allows the operator more control and flexibility.
I am posting this to get opinions from other readers of this NG about
crowned vs. flat wheels. I tend to believe Duginske's information more
because it's more complete, presenting both sides of the story. Vaughn
is obviously a knowledgable writer, but may have not mentioned the less
common flat wheels because of length constraints. What do you think?
BTW, I haven't restored the saw to the point that I could try it out
yet.
M.A. Martin
James V. Seelye
from my grandfather about 40 years ago. Like yours, it has flat
wheels.
I have put several sets of new tires on the saw. I found that tries for
a 12" Craftsman metal cutting bandsaw fit and worked fine on my saw.
The tires are installed by first precoating the wheels with rubber
cement and letting it dry to touch. The tires are then stretched
slightly, worked over the wheels, carefully aligned to the edges of the
wheels and allowed to set overnight.
I true the tires with a 180 grit sandpaper pad glued to a flat board and
guided against the running wheels. I hinge the board from another board
mounted to the saw table and carefully align the assembly to be flat
with the wheel rim. The tire is lightly sanded until the wheel is round
and the surface is flat. The upper tire is driven by running an
electric drill driven wheel against it.
This procedure has worked well for me for many years.
Jim Seelye
Trevor Galvin
"M.A. Martin" <m...@unixg.ubc.ca> wrote:
> M.A. Martin
I read the article on how to do the crown yourself. In esscense you've
got to fabricate a holding device for your router to the bandsaw. Not
something you can pump out in an hour or two. I don't see why the tire
manufacturers can't make them with crowns built in. I can just smell
the burning rubber.
Another thought would be to glue a mini band, say 1/4 the width of the
tire about .025" thick to the wheel. Stretch the tire over it. That
should give you a crown.
Trevor
Steven O. Smith
M.A. Martin wrote:
>
> This posting is prompted by a bandsaw I recently obtained for
> restoration: a 14" Walker Turner unit. BTW - thanks to all who have
> provided helpful information on the saw so far!
>
> This saw has a "flat" surface on the wheel. Most current saws (such as
> the Delta units) have a "crowned" surface which causes the blade to
> track in the center. The advantage of this is more stable tracking.
> The disadvantages are that less of the blade surface is in contact with
> the wheel, and this can be a problem with wide blades.
> In Mark Duginske's Bandswaw Handbook, there is a lot of information on
> both crowned and flat wheels. He then goes on to say that the crown is used because it
> makes tracking very easy, whereas the flat wheel takes a little
> practice, but it allows the operator more control and flexibility.
>
> I am posting this to get opinions from other readers of this NG about
> crowned vs. flat wheels. I tend to believe Duginske's information more
> because it's more complete, presenting both sides of the story. Vaughn
> is obviously a knowledgable writer, but may have not mentioned the less
> common flat wheels because of length constraints. What do you think?
> BTW, I haven't restored the saw to the point that I could try it out
> yet.
>
> M.A. Martin
I have a Kity wood bandsaw. It did take a bit of practice to learn to
track the blades, especially the smaller blades. I think the system
works fine after you spend ten minutes learning how.
I still haven't gotten my 1/8" blade to stay on, however.
--
Steven O. Smith
Steven....@nsc.com
Phil Rose
In article <33642C...@heart.net>, "James V. Seelye" <see...@heart.net>
wrote:
> M.A. Martin wrote:
[snip]
> > I am posting this to get opinions from other readers of this NG
about
> > crowned vs. flat wheels. I tend to believe Duginske's information more
> > because it's more complete, presenting both sides of the story. Vaughn
> > is obviously a knowledgable writer, but may have not mentioned the less
> > common flat wheels because of length constraints. What do you think?
> > BTW, I haven't restored the saw to the point that I could try it out
> > yet.
> >
> I have a late 1930's vintage Walker-Turner 12" bandsaw that I inherited
> from my grandfather about 40 years ago. Like yours, it has flat
> wheels.
> I have put several sets of new tires on the saw. I found that tries for
> a 12" Craftsman metal cutting bandsaw fit and worked fine on my saw.
> The tires are installed by first precoating the wheels with rubber
> cement and letting it dry to touch. The tires are then stretched
> slightly, worked over the wheels, carefully aligned to the edges of the
> wheels and allowed to set overnight.
>
> I true the tires with a 180 grit sandpaper pad glued to a flat board and
> guided against the running wheels. I hinge the board from another board
> mounted to the saw table and carefully align the assembly to be flat
> with the wheel rim. The tire is lightly sanded until the wheel is round
> and the surface is flat. The upper tire is driven by running an
> electric drill driven wheel against it.
>
> This procedure has worked well for me for many years.
>
> Jim Seelye
And the relevance of this response to Mr. Martin's question is...???????
--
Phil Rose
M.A. Martin
Phil Rose wrote:
>
> In article <33642C...@heart.net>, "James V. Seelye" <see...@heart.net>
> wrote:
>
> > M.A. Martin wrote:
>
> [snip]
>
> > > I am posting this to get opinions from other readers of this NG
> about
> > > crowned vs. flat wheels.
<snip>
>
> > I have a late 1930's vintage Walker-Turner 12" bandsaw that I inherited
> > from my grandfather about 40 years ago. Like yours, it has flat
> > wheels.
> > I have put several sets of new tires on the saw. I found that tries for
> > a 12" Craftsman metal cutting bandsaw fit and worked fine on my saw.
> > The tires are installed by first precoating the wheels with rubber
> > cement and letting it dry to touch. The tires are then stretched
> > slightly, worked over the wheels, carefully aligned to the edges of the
> > wheels and allowed to set overnight.
> >
> > I true the tires with a 180 grit sandpaper pad glued to a flat board and
> > guided against the running wheels. I hinge the board from another board
> > mounted to the saw table and carefully align the assembly to be flat
> > with the wheel rim. The tire is lightly sanded until the wheel is round
> > and the surface is flat. The upper tire is driven by running an
> > electric drill driven wheel against it.
> >
> > This procedure has worked well for me for many years.
> >
> > Jim Seelye
>
> And the relevance of this response to Mr. Martin's question is...???????
>
> --
> Phil Rose
Mr. Seelye did answer of my question - from his post I learned that
his Walker-Turner saw works fine with flat wheels and that I shouldn't
worry about not having crowned wheels on my saw. He also included some
(IMHO) very helpful information on setting up tires on flat wheels. A
number of other Gentlemen have responded privately to this question, and
the consensus seems to be that flat wheels are great - only if the saw
is built to exacting tolerances. Crowned wheels can help a saw that
may be slightly out track like one that is dead on. There are some
advantages to both systems, but the flat wheel seems to require a higher
degree of wheel alignment accuracy to work properly.
A number of people have indicated that their restored Walker-Turner
tools are well built and great performers.
Many thanks to all who have responded (including, of course Mr.
Seelye!).
M.A. Martin
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<included to stop my server from preventing this post because it
contains more old text than new text; sorry for the waste of bandwidth
but I feel that it's important to fully quote Mr. Seelye.>
moredu...@gmail.com
Anyhow, my theory is that a blade will always track to the high side because more pressure on the high side of the blade bends it ever so slightly on that side and steers it back to the top. Belt sanders and band saws work on this principle with crowned tires. Mathias explains it well here:
https://www.youtube.com/watch?v=6sM0Qjumyro
So what about flat wheels? My bet is that the wheels are towed in compared with each other. It is only very slight, but it keeps the blade tracking to the rear of the wheel and in contact with the blade guides. If someone wants to verify that their Walker Turner has co-planer wheels or slightly tow in.
That's my .02 for a thread from 1997. ;)
Leon
the wheel that provides more friction/traction, typically the high spot.
If you drive your car parallel against a curb the tire will naturally
try to climb the curb. I think this is a similar principal with the blade.