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The DoAll 16" LHF Bandsaw, Part 7:
The tracking issue was a bit of a puzzler- whereas in most bandsaws, the wheels are "crowned",
my lower one was tapered, and considerably so.
Now, while that made a certain amount of sense, it turned out to not be the case. As I was looking for parts,
I scored a vintage hardbound DoAll book off of eBay.
Printed in 1943, and apparently used as a school textbook in 1945:
I was hoping it would be a technical manual full of tips, methods
and specs, but it's really more of a very thick
sales brochure. More
"here's what our saws can do!" than "here's how to set up and run that
It's not, however, entirely void of good data, and early on, it
Ah ha! Then the lower wheel is probably not correct. I'd suspected
that the "tires" had been replaced-
they're in pretty darn good
condition for a machine some sixty-seven years old. So what probably
happened is whoever installed the new ones, misinstalled the lower one-
it's slightly too wide, and
it rides on the outer lip, rather than down
in the 'groove', giving it a taper instead of a crown.
Yep. When the blade was in place and tracking on the lower tapered
wheel, it pushed quite hard on
the guide thrust rollers- to the point
the back of the blade had worn through one of the thrust
well into the hardened body of the bearing itself.
So the tire needed to be fixed. It's on there quite firmly, and
resisted any effort to shift, move or slide it.
I suspect it's glued
down. I toyed with the idea of taking the wheel off, mounting it
somehow in the big
Springfield, and using an extremely sharp blade to
turn a bit of the rubber off (to crown it, not remove it
I wasn't sure how well that'd work. And, of course, the Springfield
isn't exactly up and
running anyway, so it's kind of a moot point.
I decided to try and grind it down, using a coarse
sanding disc in an
air grinder- I'd just spin it in place, using the saw's own drive,
while I ground it to
shape. I figured if I managed to screw it up entirely, new tires are easily
available and relatively
inexpensive (and I may have to replace one or
both before too long anyway.)
So I gave it a try.
It was surprisingly slow going, but I eventually managed to coax the crown at least somewhat closer to the center of the wheel.
I didn't want to go much further as I was starting to hit cord in
places, but now the blade tracks much better.
Not quite centered yet,
but it does at least move somewhat in relation to the upper wheel
With that at least considerably improved, it was time to organize
the guides. On these saws, they use two hard-steel
wear bars on either
side of the blade, and a roller bearing to take the thrust at the back
of the blade.
To minimize wear, the thrust rollers use replaceable
hardened inserts to take the actual contact from the blade.
As mentioned, the tracking was such, for so long, that the pressure
from the back of the blade had worn those
inserts badly- one was
completely eroded away, to the point the blade had friction-sawed it's
into the bearing itself, the other had worn to near paper
Replacement parts for this old a saw are no
longer available- besides
the fact I appear to have an uncommon (for its' time) "high speed" saw,
a different kind of wear insert. Typical saws of the day
used a "cap" over the bearing, while this 'high speed'
guide uses a
"thumbtack" shaped insert retained with a snap ring.
Since I was going to have to make these,
I needed to know how thick to
make them, so they'd more or less match up with the back edge of the
as it was free running. Once I had the blade at least reasonably
adjusted, I could now measure and get a
decent spec to match.
I turned a couple of examples out of O1 oil-hardening steel.
And of course oil-hardened them. :)
I needed them as hard as possible, so I left them as-treated, with no tempering.
They just slipped into place, and once in, the blade tensioned and the guide blocks installed.
I fired it up, set the tracking to just before the blade touched the rollers, and gave it a try.
Wood cuts great, and so does aluminum. But before too long...
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Information contained in
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purposes only. Our methods are not always the best,
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Keep your fingers away from the spinny blades o' death and you should
be all right.