Random layer offsets position x y. Help

[jonbez 0]

Hi

I'd appreciate any advise on my issue

I've had my ultimaker well over a year and never had any issues till today.

Everything is printing fine but at random heights in the print it move the print location slightly and the next layers above are offset a few mm

I have standard print setting and it even happens when printing the ultimaker robot the came on the sdcard.

I have photos if I can upload somewhere

Thanks in advance for any suggestions

[IRobertI 521]

Most likely you have a loose pulley:

http://support.3dverkstan.se/article/23-a-visual-ultimaker-troubleshooting-guide#shifted