SO3 x-axis problem

The first time I set up the so3 xxl and ran the ‘hello world’ test, it came out fine. But after trying to cut some wood using the machine, it somehow gave a distorted image. So I went back to running the ‘hello world’ test again just to get a pattern to rectify the problem. GRBL wasn’t the problem as it was already on default. The belt is just fine as homing the cutter works fine and moved smoothly. moving the cutter individually(x,y,z) too. As you can see from the image below, the distortion only applies to the x-axis. they y-axis behaved as it’s supposed to. I am very new to this machine. Any comments or suggestions would be of great help.

Thank you!

It’s (99% sure) because the motor pulley’s set screw is NOT on the motor’s flat.


The problem and solution were exactly that. Thank you very much!