On 2012-02-20, wrote:
I have a cheap 4x6 band saw which I bought on sale from Busy Bee and
which came with a Harbor-Freight manual. I have also downloaded a
Grizzly manual for their equivalent saw.

I am having a persistent problem with tracking of the blade on the
lower (driven) wheel: the blade runs about 2/3rds on the wheel. I have
re-done the tracking procedure on the top wheel where it is
satisfactory. I have tried different tensions.

The only *correct* tension on these machines is as hard as you
can twist the knob by hand -- and perhaps a little more. The tension
knob is too small for the task. :-)

If I move the blade
manually *backwards* by rotating the pulleys the blade slots in fine,
right next to the shoulder. If I move it forward, manually or by the
motor, it goes back to its previous position.

The saw cuts OK and there has been no tendency for the blade to slip
off the wheels. I am inclined to accept it but I was wondering if
anyone else encountered this and what, if anything, they did about it.

I'll bet that the third ball bearing in the guides (the one
which presses against the back edge of the blade) is set too far against
the back of the blade, forcing it forward. The bearing should be
mounted on an eccentric, and thus fairly easy to adjust. (Note that
there are two flavors of the guides. The ones which came with mine
(bought new from MSC over a decade ago) has the bearings mounted to a
chuck of forged steel -- nice and rigid. Others that I have seen often
have the guide assembly bent up from mild steel about 1/8" thick or a
little thinner, and those tend to loosen over time as the mounts for the
side bearings bend.

I would suggest that you start by adjusting both back bearings
as far back as you can get them. Then start by adjusting the one
closest to the wheel until it moves the back of the blade just barely
clear of the flange on the wheel. Then adjust the other so it is just
barely touching the back of the blade while it is running free. When
you start to cut, it will move that part of the blade into firm contact
with the bearing, too.

But it *could* be a worn bearing in the bottom wheel's axle.
Did you buy this *new*, or was it from someone else who had bought it
from Busy Bee some time ago?

And, BTW, it is a good idea to open the gearbox, clean it out,
and refill with proper gear oil. They frequently have casting sand in
there, and grind the gears to death over time.

The other issue is the quality of the chips: The Grizzly manual has an
interesting chart explaining what needs to be done depending on the
shape of the chips. Nothing I do seems to make a difference - they are
always powdery!

What metal are you cutting with it? I suspect that the Grizzley
manual is assuming mild steel. (It might help if I downloaded it and
read what they say, but it is too late tonight. :-)

Good Luck,
DoN.

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