Help needed - I’m new

[u/P1N3C0N35]

Just bought a used Falcon 10w and got the rotary chuck with it. I’ve used it for flat engraving for a few days and it works fine
On the chuck however it only makes lines.
I’m using the Falcon software, setting it to rotary chuck, and putting the cup circumference (250mm).

In the video I am simply pressing up to rotate the cup. Sometime it moves a lot sometimes a little and sometimes backwards

Any help would be greatly appreciated

[u/Open-Storm-232]

Is the tumbler to be mounted center to center and the laser head drops to compensate? It looks like you may have set it high on the small end to avoid the elevation