The punch line is that I can't get my drum sander to track. This post is a total Hail Mary, 4 seconds left, on our 30, throwing the 40 yard bomb. If you guys can't help me, no one can. Delta service of course has been worthless. I just hate the thought of junking an otherwise functional machine.
I've had this sander at least 10 years and it worked well for most of that time and without significant tracking issues. 2 years ago I had some table elevation issues and stripped it half down and put it back together again using the manual as a guide to get the set up right. Everything is now level and square, table elevation works smooth, but the conveyor belt consistently moves to the right (when at the machine front) after about 5-6 belt rotations and starts to fray against the roller bed.
Here is what I have tried without avail, both with the table mounted on the sander (with and without wood running through it), and with the table removed and running on its own without a wood load (please see pics below but NOTE that the 2nd pic is upside down):
- 1 old belt, 2 new belts, tried both directions.
- Checked rollers and table: table flat within 0.004", roller runout 0.002".
- Cleaned roller bushings.
- Checking roller coplanarity with top of table, fine.
- I have adjusted the rear roller so that it is exactly parallel to the table, and then adjusted the right side (RRA in pic) to be 1/8" away from the table (right drift seems slower), or 1/8" closer (drift is faster).
- With each of the above attempts, I gradually increase tension on the belt with the front roller adjusters (FRA in pic) until the belt just starts to move forward (blue arrow); if I tension the left side more than the right, the belt really moves to the right (as expected); If I tension the right side more (even to the point where the left side is grossly loose), it seems to move less quickly to the right, but right it still goes. Even with max tension on the right it goes to the right - just doesn't make sense. I even replaced a belt because I was concerned that I had overstretched the belt and that was the problem.
I'm a reasonably smart guy and do research for a living, so I generally know how to analyze a problem. But this one has me stumped. I can't even think of anything else to tweak or measure! I would greatly appreciate any of the learned opinions out there. I have no problem spending money for a new one, but I just hate to take stuff to the dump.
top view with belt.jpgtable and rollers.jpgside view with belt on.jpg