Quote Originally Posted by crabjoe View Post
Fred, when I took the video, I hadn't even powered it up yet. I was finishing up the build.

Well I found the problem. The one thing that fixed the problem was just tightening the dang pulley itself. I guess when there's tension on the pulleys, there was enough play that caused it.

Things I tried that didn't help. The number #1 thing that shocked me, because it made the problem worse was adjusting the pulley on the motor. That pulley sits about a 1/4 inch lower, in relationship to the frame, as this pulley. When I moved it to match, it made the problem way worse.

What made me think it was the actual pulley the belt was riding up and down on.. Well, I had check the angles on it without the belts on. I tried shimming it, which made the problem worse.. sometimes in the opposite direction, blah, blah, blah, then I just started messing around with belt tension. I took the belt in my hands, and just pulled back and forth to see what happened... I tried different positions as in in holding the belt slightly high than my right and what not. Tried more tension and less tension. I just wanted to see what happened based on belt tension and angles. That's when I had the light bulb moment. I noticed the less belt tension, the less vertical movement. At that point, I took an allen wrench and just tightened the center bolt by a 1/4 turn. put the belt back on and bam! then problem was like 50% less. I gave it another turn and checked and it was fixed.
Could you go into a little bit more detail about how you tightened the pullies? I'm running into this same problem, I've loosened and tightened the screw holding the pulley on the right bracket a few times, but with little difference. Did you tighten the nut between them too? What was your process?

For what it's worth, I am running the printer, and it does not seem to have any effect on the quality of the prints, no ringing, no z-artifacts, etc, it just sounds like it's chewing itself up.