My UMO+ will not print a perfect circle

[Blake215 0]

I have an UMO+ and it will not print a good circle on the factory settings. Therefore, I tried the nickel calibration test on thingiverse, to calibrate my X and Y axis, I have done it over 11 times, and have followed the instructions to change the steps/mm. However, nothing I have done has fixed this problem solar, and it is very difficult to make accurate prints if my printer cannot make a circle. If anyone can help please let me know what I need to do. In these photos the rectangle at the top is supposed to be square and the oval thing direct under it is supposed to be a circle.

[IRobertI 435]

You probably have a bit of backlash caused by loose belts:

http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#circles (UM2 is pictured but it applies to your UMO as well)

[neotko 1,393]

Also check and recheck the calibration. On umo+ mxl belts at some speeds it's easier to see even a small error in calibration (I mean even a half millimeter).

On the long run. Print and install twisterblocks by chopmeister and if you really care about precision ditch the bad umo/umo+ mxl pulleys and upgrade to gt2 (the ones um2 uses). I changed my 3 machines to that (two on the assembly day) and it's just fantastic (slightly better but noticeable).

About t gt2 upgrade on umo/umo+

https://ultimaker.com/en/community/15874-mxl-vs-gt2-print-results

A better side blocks:

https://www.youmagine.com/designs/twisterblocks

[Blake215 0]

You probably have a bit of backlash caused by loose belts:

http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#circles (UM2 is pictured but it applies to your UMO as well)

 

Thank you, I did what you said and it really helped. After tensioning those belts I followed the instructions on this link, http://blog.mcmelectronics.com/post/3D-printer-calibration#.VoMYr4RlngG ,to calibrate my X and Y axis and I now have perfect circles.

[Blake215 0]

Also check and recheck the calibration. On umo+ mxl belts at some speeds it's easier to see even a small error in calibration (I mean even a half millimeter).

On the long run. Print and install twisterblocks by chopmeister and if you really care about precision ditch the bad umo/umo+ mxl pulleys and upgrade to gt2 (the ones um2 uses). I changed my 3 machines to that (two on the assembly day) and it's just fantastic (slightly better but noticeable).

About t gt2 upgrade on umo/umo+

https://ultimaker.com/en/community/15874-mxl-vs-gt2-print-results

A better side blocks:

https://www.youmagine.com/designs/twisterblocks

 

That would probably be the best long term solution. That will be the next upgrade that I add to my UMO+. Thank you for the help.