Chattering, Shuddering and Snap! Oh My! My Adventures in Trying to Cut Aluminum

LiamN · April 12, 2021, 1:07am

MadHatter:

Turns out, it was not the V-wheels on the Z-axis like I originally thought, but the GT belt was just too loose. I loosened the V-wheels a bit (they were too tight because I thought they were the culprits at first) and then tightened the GT belt a tooth or two. It was actually a pain in the a** to get the belt to stay at the new location.

What appears to happen is the little steel angle bracket that holds the belt gets bent to less than a 90deg angle on install, which is fine, but when you go to try to take up some slack, the (now less than 90deg) angle piece does not hold the GT belt while tightening it. I tried two or three times to get it to stay with no luck - until I used my pliers and bent it a bit and made it about 100-110deg.

Then, with the bracket bent, it presses the GT belt against the aluminum extrusion while being tightened and holds it until it is tight. I don’t have a video of it after tightening, but it does not bounce anymore.

Been there, more V wheel tension means more backlash, nothing is free…

I suggest you re-check your X and Y calibrations now that you’ve tensioned the belt.

You can measure and level up the belt tension quite easily with a phone app.

I found that just pressing down with a finger on the overlapped belt would let the teeth engage well enough to get me the target tension. It seems to be a bit harder on the XXL axes as you need to pull the belt twice as far to get the same extension and therefore tension on the belt.