On Mon, 6 Jun 2005 19:13:57 -0500, Hax Planx wrote:
Brian Mahaney says...
Hello all,
I bought a 14" Powermatic band saw a little over a week ago. I'm not that
familiar with it yet. Today I picked up a 3/4" blade on sale at a local
lumber supplier. I tried to install it a little while ago but ran into a
few issues. It went on fine, or so it seemed. The lower bearing that
rides at the back edge of the blade does not seem to have enough travel to
allow the blade all the way in. It goes most of the way, but it does not
seem possible to set it according to the owner's manual. In other words,
it will always be touching the back of the blade and it touches it pretty
hard if you know what I mean. To complicate matters, that bearing doesn't
spin freely anyway. It's too stiff to spin like the rest of the bearings.
I will tinker with it and replace it if necessary, but the travel issue is
still a problem. The combination of the two problems resulted in a
slightly hot bearing with a slight groove beginning to wear in the bearing.
This was after a short test run.
Questions: Should I pull the blade off and just accept that a 3/4" blade
simply wonąt fit even though it is supposed to fit? I seem to remember a
recent discussion saying that fitting a 3/4" blade on a 14" saw is a common
problem. I sure did like the result of the test run I made. Are there any
adjustments that I am missing that would remedy the problem? Anyone
familiar with this saw enough to tell me what I need to know to run a 3/4"
blade in it?
Thanks,
Brian
There are some simple adjustments to setting the thrust bearings. Like
David said, there is another adjustment where the guide and thrust
bearing assembly bolts to the frame. Running your saw in a bind the way
you did was extremely unwise and dangerous, not to mention murder on
your nice new saw (Wanna trade?).
No it wasn't unwise or dangerous. It was not in a bind. The blade moved
easily and was close to the center of the wheel. There was pressure on the
thrust bearing, but it was no more than what would be encountered while
pushing a board through. The slight damage to the surface of the bearing
extended all the way around the bearing indicating that the bearing was
turning. However, it was turning slower than the blade causing the blade
to scratch the shiny surface. As it turns out, the bearing was rubbing
against the assembly housing slightly. Apparently, the design does not
include a stop other than the bearing hitting the housing.
The damaged bearing should be flipped
or changed.
I will flip the bearing.
Don't use the damaged face anymore. Your saw won't perform
well or safely if it isn't adjusted with care. The thrust bearings
should be adjusted to where they just barely don't move when the machine
is on, but will as soon as you start cutting a piece of wood and the
blade moves a fraction of an inch (1/64 is the rule of thumb) and braces
against them. Guide blocks should be adjusted similarly close, as close
as possible without touching when the blade is moving, and behind the
kerf of the blade. When I change blades, I move everything way out of
the way, install the blade, tension it and then turn the saw on for a
few seconds so that the blade finds its equilibrium. Then you can do
the adjustments, turn on the saw and check to see if your adjustments
need any tweaking. If you are lucky, your adjustments will keep, but
you should keep checking them as long as you are using the saw, because
if your saw is anything like mine, the blade will drift for a variety of
reasons, including sawdust building up on the wheels. These should be
thoroughly cleaned before using the saw. It may all sound like too much
trouble, but that's the price of using a band saw. Your saw should run
a 3/4" blade with ease, but most people stop at 1/2" or 5/8" for 14"
saws. A 1/2" Timberwolf blade resaws perfectly adequately for my
purposes. You should get the Duginske book. It will tell you more than
you ever wanted to know about band saws.
Duginske's book is on my list. I don't have a problem with tweaking a band
saw. As you said, it's the nature of the beast. At this price point, I
would have liked to see a little bit better quality control or design,
whatever the problem was. Honestly, I like the saw, but other than the
extra gadgets (light, chip blower), I don't see the price justification.
The saw had no better fit or finish than my Grizzly table saw, or my
Geetech jointer. There were chips in the paint right out of the box (this
didn't bother me in the least); there was some overspray and some under
spray of certain areas (no big deal to me). Although I can say it is
slightly better than other equipment I have seen, it's just not enough from
the quality perspective. Again, I guess the light and chip blower are what
makes it cost more. I received a free mobile base with it. That was an
incentive to me also.
Thanks for the advice,
Brian
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