Soon I'll install a riser block on my Taiwan 14" BS. Right now it's
about 3/8" out of being coplanar. Rather than shim the upper wheel,
I'd like to seat the upper arm more correctly so the wheels will be
Any tips? Caveats?
With the two dowel pins you won't be doing too much in the
way of aligning it other than the way it's already going to
align itself. In other words, it will only fit one way.
By the way, up till now has the myth of coplanar presented
itself as a problem?
Coplanarity(izzat a word?) would more likely be approximated by adding or
subtracting washers behind the top wheel rather than frame adjustment. Frame
shimming is more useful to bring the guidepost into alignment with the blade
along the guidepost's travel, 'iffin it's at all like a Delta. Like UA hunnert'
asks, has there been a problem at 3/8ths out? Tom
Someday, it'll all be over....
Hello Mr. 'Saur,
What's to prevent me from drilling new holes for the pins? I've read
that some people have done this to their (stock, not riser) units
because they weren't aligned correctly in the first place. My riser
kit even comes with a nice drill bit for that purpose.
I won't pretend to know whether coplanar wheels make a bit of
difference, but theoretically the idea that your two wheels should
line up seems just common sense to me. Since I'm messing wth a new
riser block anyway, I thought I'd give it a try. If it works out and
makes any difference I'll let you know.
Absolutely nothing. If you feel you can precisely align
four holes in two mating pieces of cast iron then you go
girl. Me? I wouldn't touch it with a ten foot (approx. 3
metre David) pole.
You're kidding, right? Isn't this kinda of a sign that the
company that made the saw "isn't really too sure but we'll
ship along some tooling for you to clean it up in case we
didn't get it right"? Not something I'd be putting in the
ad copy if you know what I mean.
There is no pretending (or dress up) required with this one.
Either the band tracks or it doesn't.
Does the band track correctly?
In theory you are correct but with this one theory isn't
needed onna 'count of we have a real world situation that we
can draw from. The basis for my argument is, "if the band
tracks, you don't have any worries". To be seeing demons
where none exist might make for a great hobby but isn't
necessary for good fun with wooddorking.
So, we ask again. Does the band track correctly?
Now this is where the choo-choo comes off the tracks. An
adjustment made to the riser to compensate for the myth of
co-planar might work if your wheels were "slightly" out of
alignment. In your case, and if I m'member correctly, your
wheels are out 3/8". This would mean that you would have to
re-drill the holes 3/8" away from where they presently are.
I'm not sure the fixing bolt will fit with that gross of a
misalignment, not to mention how screwy it would look. And
oh by the way, what if after all of this you've gone an
introduced further error? Re-read this last sentence,
especially if you have a problem with cause and effect and
seeing something to the end injineering wise.
Again, I think you need to determine if the myth of
co-planar is a problem first. Tackle that independently of
the riser block. If you cannot contain yourself and feel
you must screw with the riser it might make more/better
sense to shim the riser on one side or the other. This will
tip the upper wheel in or out. Now, the only problem with
this is you'll now introduce a situation where your upper
blade guides are now totally out of alignment and you'll be
See where all of this is going? By orbiting around the
issue (not looking at/doing something specific with/to the
upper wheel) you begin the begets and just create more work
for yourself elsewhere. I'd be willing to bet that by the
time the whole thing is over you'll be too afraid to operate
the saw because it'll be so held together with chewing gum
and duct tape that simply turning it on will throw out all
Hear me now, believe me later.
Long and detailed and funny explanation.
Or what you're saying is go with the stock set-up. Put her together and see if
she gives you straight cuts (or controllable curves). If that happens, don't
screw with it.
"It is not strange... to mistake change for progress." Millard Fillmore
firstname.lastname@example.org (Charlie Self) wrote in message
You guys are probably right. What I'll do is put the riser block on
without messing with a re-placement, shim for coplanar if it's only
1/8", put on a decent new blade, then see how she runs. Go from there.
Good advice, both of you.
I had some great metal shop teachers. I think I can handle those holes
if I want to....
Nope, but the whole kit cost me all of $10 at a hardware store yard
sale, so it's possible someone tossed it in for fun. The size and type
of bit are curiously appropriate though.
When I DAGNGS on riser blocks and coplanar I read several threads
where participants had moved the arm rather than shim because the
bearing shaft was not long enough to achieve coplanar by shimming
alone. So the process is not uncommon. Among cheaper brands of BSs,
the arm is often not accurately mounted in the first place.
Since earlier thread participants mentioned that they had remounted
the arm and they didn't mention any big trouble doing it, I am curious
about your hesitation: have you tried it?
Well, to be fair, the argument about coplanar wheels and whether
they're useful or necessary does not, for its proponents, rely on
whether the band tracks without it. Or is that your understanding of
So far. But I've only tried it once, with the blade I got with it, a
3/8" blade. *And* the upper wheel is tilted ALL the way in order to
get it to track. Now, my experience with other bandsaws tells me that
getting a 1/2 or 3/4 blade to track on this unit might be difficult if
a 3/8" tracks only on full tilt. I want to use 1/2" blade mostly, so
it looks like shim or move the arm, or see about moving the lower
wheel on the shaft. Since I'm installing a riser block, I thought to
consider a riser modification first.
Very good point. Accurate placement is assumed. My usual procedure
would be a mock up with clamps, spot welds or whatever temporary fix
works to see if things will line up conveniently. Tom's point about
the guidepost (thanks Tom) and yours here about the other alignment
issues are exactly the caveats I'm looking for. Honestly I hadn't
considered those issues (although a mock-up would probably have
revealed them), so thanks is in order.
OK, I will. Where's the best place to read about the opposing view?
<snip ideas about shimming the post, which sound as bad to me as to
Quite possible, and I appreciate your monitions.
That's a bet you don't want to take.
H, who made more pipe bombs and zip guns before he was 12 than all the
unisaws you've ever touched.
email@example.com (Charlie Self) wrote in message
Half and half, I'd say. But two things are certain: I'm amazed I ever
lived through it, and I can't believe the shit our neighborhood kids
got away with.
The bombs and zips, BTW, were not for city trouble, we just blew 'em
up and shot them in the desert for fun. The point being that my
backyard engineering experience has taught me well enough when to fear
and when not to. I can manage tweaking a BS....
My hesitation comes from working with machines and real life
usage and a fairly good ability to predict the outcome of a
given procedure which for the most part comes true more
often than not. When it doesn't I file away what I've
learned and use it the next time a same or similar situation
Have I been doing it wrong all of these years?
My "understanding of their position" is,
1) Wheels not coplanar can be the cause of bands not
2) A band can track on a saw with wheels not coplanar.
Conclusion: Coplanar, it could be the solution as well as
That's why I was asking (and secretly wondering why you were
skirting around the issue).
Mock ups are good. I wouldn't braze the cast iron for all
the obvious reasons.
I couldn't tell you. My position on coplanar is from real
world situations and usage (see above) and not blindly
following the book writers. I suppose if you really have to
see the words in print you could search Google but you'll
more than likely only find what I've had to say. Me, not
being a book writer, would probably make anything I've said
invalid, that is if you only believe what you read in books.
I'm sure your mother is quite proud to see you listing this
on your resume.
By the way, before you go Bay Area Dave on us here and start
getting your tutu in too much of a bunch, you asked the
question, right? Had I known this was all a foregone
conclusion on your part, I'd a passed on by. My hopes were
to see to it you didn't go and screw up your saw or spend an
awful lot of time orbiting the solution. I can see now that
your saw is in very capable hands and should you become too
frustrated with it you possess the knowledge for the proper
means for disposal.
Knock yourself out there now.
UA100, who is usually better with troll detection but thanks
you none the less for this chance to recalc the meter...
On 4-Apr-2004, firstname.lastname@example.org (Jeffrey Thunder) wrote:
Under tension, the blade is forced to ride tight to the wheel
(well, tire actually). Think of two wheels that are coplanar.
The blade is straight up and down between the wheels.
Now consider non-coplanar. One wheel is to, say, the left of the
other. The blade has to be forced to the left as it leaves one
wheel and goes to the other:
Obviously highly exaggerated due to the limits of ASCII art.
The non=coplanar puts additional stresses on the blade and
the blade is constantly twisting to conform to the tires.
You can force it to track, but that doesn't mean you're
doing it right.
I gotta agree with Keeter on this one; coplanar is not all
it's cracked up to be. I have a Powermatic which tracks all
size blades perfectly and it isn't coplanar, by a small
amount when the tension is set. I adjusted it coplanar for
grins, and it ran like crap. The mfgr. knows a little bit
more about how to design the tool then the net pundits, in
I followed Duginski's instructions, BTW. While I generally
liked his Bandsaw book, the coplanar thing is NOT exactly legit.
In theory, it sounds great! In practice, not all saws work
well when "adjusted" to coplanar geometry.
If you have had good success with coplanar, I'm not about to
disagree with your experience, but for my saw, leaving it
stock is best. The good news is I didn't break anything and
only wasted an hour or two screwing around with it (mostly
to find a suitable shim).
Michael Daly wrote:
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