Troubleshooting Drive Belt Alignment

A woodworker gets help with the belt tracking on a drum sander. January 8, 2010

I have a Performax 36 X2 drum sander. For years now I have had the problem with the drive belt not tracking and I am determined to fix it. I know I am not the only one as my friend has the same machine with the same problem. I have tried everything, particularly with drive belt tensioning on the end it is tracking towards. I can have it really tight at that end and floppy loose at the other and it still tracks towards the tight end. I have bought three or four new drive belts and it has not seemed to help. I am going to try putting a crown on the rubber drive roller to see if that helps. Has anyone out there had this and solved it? I cannot afford a big belt sander at this time.

Forum Responses
(Solid Wood Machining Forum)
From contributor R:
You are thinking backwards. The belt will track toward the "tight end" or high side. Like a crowned pulley, the belt will run up towards the high center not away from it.

From the original questioner:
Oh my god if that is the solution take away my woodworker license right now. You mean like a band saw blade drifts towards the crown on the rubber tires? I canít wait to try it to see if this is the solution. I hope you are correct.

From contributor L:
Contributor R is correct! It's easy to see like on an edgesander.

From the original questioner:
I sure appreciate the help but it did not work. I tightened opposite from the way the belt wants to drift but still it always drifts towards the motor. I tried turning the belt around but it did not help. I am back to the questionable solution of cutting a crown on the drive roller. Any other solutions?

From contributor D:
I don't have this machine but have fixed many aggravating conveyor belt tracking problems in the past. Now I approach everyone the same way. First I disassemble all of it and inspect the parts. One bearing may be stiff or seized and cause this exact problem. Then, clean and lube everything. When you reassemble, mark the nuts or bolts that adjust the roller tension so you can count the exact same amount of revolutions on each side. It should only require less than one turn on either side to track straight if you counted right. Hope this helps.

From the original questioner:
Well thank you all for your help. It bugs me that I cannot figure out the root cause of this problem, but I fixed it. I created a crown on both rollers with duck tape - at least a 1/8" crown. So now with the drive side still expanded as much as possible, it will track straight. Don't you think it has to do with the motor putting torque on one side of the belt somehow? Also I took the whole thing apart several times all the bearing are good and lubricated all the adjustment bolts work.

From contributor L:
If there was no crown to start with and no auto tracking system then you only need crown on one roller, not both. If you put too much crown on it will deform the belt and cause other problems.