Circles not round on X20 Pro

I have just received my X20 pro and am having problems with circles not being lasered correctly.
I calibrated the machine from the Machine Settings such that a 200mm x 200mm square now produces exactly those dimensions however, when a try and burn a 70mm diameter circle I get an oval with flat ends :frowning:

The belts seem to have good tension - is there anything else I should check?


This is classic mechanical backlash, due to a loose setscrew or joint in the frame.

Following all of these steps should get things snugged up and running properly:

It’s written for Sculpfun lasers, but all of the desktop diode lasers have similar mechanics, so it will look familiar.

Thanks for that :+1:
It turns out that my belts were a little loose resulting in the flat ends of the oval and I had not correctly calibrated the steps per millimetre but once that was all sorted, I get a perfect circle.

Thanks again @ednisley


It’s always surprising how just a little slack can produce such a visible result, but now that your eyeballs and fingers are calibrated, you’ll know what to look at and feel for.