Round parts are not round after printing

Rvelleko · January 10, 2023, 5:16am

I have an issue where round parts are not printed round but elliptical
this Ø34 round wheel has almost 1 mm. difference in diameter

It was sliced in this direction so it’s not just a difference in the X or Y direction, but a combination

I use the stock slicer settings for generic ABS, but it also happens with PLA

I have already tensioned the belts following the instructions in the Wiki.

Testurbator · January 10, 2023, 5:54am

Having the same problem, I am currently in contact with the support.

The upper belt is noticably tighter than the lower one, so the tightening system is flawed on my printer or something is blocking one of the mechanisms somewhat?
I guess I will remove the back and take a look at it, but first see what the support has to say.

vc_bx1 · February 22, 2023, 5:59pm

I have a similar problem. round parts are oval, square parts are strange trapezoids. Did you make any progress?

robinojones · February 28, 2023, 7:28pm

Has this been resolved? I’m having the same issue.

Kewish · March 2, 2023, 4:56am

I had the same issue. My circular parts were varying by about 1-3mm in the same 45deg direction as yours.

Your carbon rods in the X axis are dirty. To clean:

Turn off printer, loosen screws that control belt tension on the back of the printer (4x M2 hex on the back, looks almost like an outlet)
Use isopropyl alcohol wipes or spray on to rods, wipe with microfiber cloth and repeat several times, moving the toolhead to get all the gunk out.
Once the carbon residue is removed, move the toolhead to the back left of the printer, and retighten the belt screws (do not overtighten, the belts are spring loaded)
Turn on the printer, go to the control tab, “utilities” and recalibrate your printer.

After this, my circles were within .1mm of spec.

Hope that helps. Search “Bambu Lab Carbon X1 clean carbon rods” to get a video tutorial. God bless.