I had a similar problem initially when I used a really large bit for surfacing.
Switched to a 1/2" dovetail when @jamiek mentioned that he was using one.
Your machine may have a clean direction (+/- X or Y).
Use Jamie’s code generator to pick the direction leading into the lowest point on your bit if the bit isn’t trammed.
My settings surfacing mdf 2 days ago were:
; mode: surfacing
; rapid feedrate: 3000 mm/min
; raise/lower feedrate: 800 mm/min
; pen down z level: -2
; pen up z level: 0.5
; drawing feedrate: 3000 mm/min
; x extent: 160
; y extent: 140
; stepover: 12 mm
; direction: N
; perimeter: false
But you seem to be missing settings. These are the options I have for surfacing (ignore settings).
