Start position problem

The start position X0 Y100 Z0.09 seems to be out of reach on my vertex delta.
When it moves to this position one of the arms fals of.
When I manually correct the Y value to 80 then he works perfect.
What is the matter?

Could you post a picture of the printer?
Check the belts
You want them tight but not to tight.

Here is the situation at Y100

On a lot of these printers it’s the cable that’s not routed correctly
Could you send a picture of the whole printer?
Also in your picture one of the magnetic balls is out of the socket.


It’s hard to see on this photo. But the most common reason why the arms come loose is that the printer head is mounted in wrong orientation.

See picture below for correct orientation of the printer head!

Regards Velleman support.