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View Full Version : Bandsaw rocks (not musically, literally)



Tyler Keniston
03-03-2013, 7:47 PM
Hi all. I am seeking advice on removing some serious rocking/wobble from my bandsaw. It is an old Powermatic 140.
I've shimmed it where it meets the floor, so that's not an issue.
I am going to replace the v belt with a poly belt (seen in the pics) to reduce vibration and the like, but I think it has other issues too.

255983 You can see that the top wheel is not in plane with the bottom. But oddly, the wobble is still mostly there with no blade.

255982 I am thinking that perhaps the bottom wheel is 'pushed out' from where it should be. See how the belt is pulled to the right in order to line up with the motor sheave. I don't know if this is causation or correlation. If its causation, I could adjust the motor to bring that in line, but if its simply correlated with the fact that the wheel has somehow come forward and is causing the wobble, I'll probably need to adjust the wheel itself somehow.

I am also not sure exactly how to test the wheel itself for balance. Does anyone have good advice or resources on bandsaw wheel adjustments? I have the old manual for the 140, but its all of 4 pages with hardly a mention of adjustments.
255985 This is the bottom wheel (picture turned sideways). You can see that little bit of threaded shaft there. I'm not sure if that is normal to be showing? When I start the machine up, there is nothing I see visually indicating that the wheel is wobbling, but the machine itself sure is rocking. I can't pinpoint any specific odd movement though (besides the old v belt that was on there; it did have a weird vibration wobble thing going on, but it didn't seem like enough to cause the sort of shakes I was experiencing).

I appreciate any advice, resources, recommendations on how to proceed, etc.
thanks,
Tk

Myk Rian
03-03-2013, 8:50 PM
Wheel balance. Take the blade and belt off.
Spin the wheels and note where they stop. Make a mark on the bottoms of them, and do it several times again.
If those marks always are at the bottom, you need some weight at the top.
Stick-on auto wheel weights work. I used large paper clamps on a Delta I had.

255995

Gus Dundon
03-05-2013, 3:06 PM
The problem must be the wheel. Check the wheels for eccentricity.

Thomas Hotchkin
03-05-2013, 3:58 PM
Tyler
In your second picture, new belt it does not look to be inline. Check your pulleys for alinement.

Tyler Keniston
03-05-2013, 5:48 PM
Tyler
In your (http://www.sawmillcreek.org/#) second picture, new belt it does not look to be inline. Check your pulleys for alinement.

Yeah its definitely not (nor was the old belt) but i'm not sure if I should just adjust it by moving the motor or if the wheel may need to be moved. I'm sure its not common for a wheel to get pushed around but I'm curious if its even possible and could explain why its shaking/ isn't in plane with the top wheel. I know this is specific to the model, but I don't really know how to adjust the wheel to put it in plane with the top wheel.