New Duet causing issues

Hello all, hope someone can help me as I'm completely new to the Duet board.

Just finished installing the new board and followed the RepRap Wiki to calibrate it but am having some quirky issues with printing.

1) after i finished a print or if i stop it half way i want to return the print head back to X-home, however as it travels to the end stop the sensor passes over the edge of the print bed and recognises it as the end stop! it only returns back home properly if i move the sensor over empty space before i press X-home.

Surely this can't be right?

2) it can't seem to print round stuff very well any more. The old Melzi board had no issues, but when Duet tries it, the motors seem to stutter and upon closer inspectio only one motor moves at a time. Verry odd behaviour.

Can anyone suggest a solution?

Cheers!

What sensor are you using? Usually the edge of the bed is 0, check the printer minimum x setting. It may have an offset.

You may need to increase the stepper current. The config.g supplied with the duet usually has all of them set to 800 ma.

Thanks Stephen, I'll check the x setting and the stepper currents.

The sensor itself is this: [reprappro.com]
Bought the modulated proximity sensor directly from RepRap when they were still trading.

On the sensor triggering on the bed edge, raise z some before homing. That move can be put in the slicer's end code. For when you cancel a print, create a cancel.g in sys and put in a gcode to raise the z up high enough to keep it from triggering on the bed edge.