I have recently purchased an older (green) Jet 20 inch bandsaw and have
started reconditioning it. (An absolutely awsome saw, but that is another
story). Basicly I am replacing some worn belts and tires, as well as
cleaning and aligning it, etc. I have Mark Duginske's book and have been
following the advice in the book, but the book has raised some questions.
After testing the coplanerity of the saw I found the the upper wheel was
slightly behind the lower wheel. This is a condition which Duginske says is
common and can be corrected with a spacer washer behind the bearing on the
upper wheel. I agree that this non-coplanarity is common, since I have seen
it in other bandsaws such as my very cheep 14 inch clone. But, why does it
always seems to be in the same direction with the upper wheel being further
back than the lower wheel? That coincidence seems odd enough to me that I
wonder if the saw manufacturers have have been doing it for some unknown
Does anyone know if bandsaw manufacturers purposely build in this kind of
offset into the alignment on purpose? If it is easy to adjust, why is it so
common in saws and mostly in the same direction? What kind of advantage
could it have? The blade tention does not seem capable of warping the
wheels in this manner. This saw even has adjustments for tuning the
position of the wheels, but they seem to have been purposely aligned with
the wheels very parallel, but offset in depth.
I will probably try running the saw both as it is and with the wheels fully
coplaner once I have the tires replaced and the saw put back together so I
can see how much of a difference there is. However, I doubt I am
experienced enough to notice much of a difference, and was wondering if
anyone knew more about this common irregularity.
Inquireing minds want to know.