Bad Crown after sitting idle for months

My MPCNC has been sitting for a few months. I don’t have a picture of my original crown but I know it was way better than what I’m getting now. Working area is 32"x32" but I think I’m going to take it apart and rebuild it to be 24"x24". Any thoughts on what I should pay attention to in order to get better results than this ?

Sad crown is sad! :disappointed:

I would try to fix it as is before redoing just to make sure you have identified the exact issue and can build around it. I’d check the pulleys first and the belt tension. Perhaps something got loose.

With the machine off and move slowly through the range of motion in both x and y and see if anything is binding. Cables? Bearings? Debris?

The right side looks good. It seems skewed as it goes over left.

How are your diagonals from corner to corner?


The pen is probably smashed down too hard. That’s why it is wandering sideways.


Your X axis is very loose. Really bad backlash in the X direction, but Y looks okay. Check belts are tight, pulleys are tight. With steppers engaged, try wiggling by hand and see what moves.


My sincere apologies for replying so late to this, but 2020 happened.

There was a problem with the X axis. The drive belt pulley was loose. I roughly squared things up, tightened the set-screws and we are up and running again.

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