Openbuilds Acro 1010 with grbl shield on arduino ... Image shift at random location

Hi Guys,
This is my first post in the forum :innocent:
I built a Acro 1010 frame and have put 15W(5.5W optical) laser module. Everything works fine on it except when engraving a big image (200x200) randomly the image gets shifted across X axis. At times it happens two or three times. Any help would be great !!!


are you sure of tension on X belt?

I’ll redo and get back… BTW I am using 20 tooth pulley, recommended is 14 tooth. Does that make any difference ? On Y axis things work fine with 20 tooth.