Thank you. Well, the machine runs smooth, I believe it´s something else. There is part in the pst file that beaks large rotary moves. I created a big arc and made de gcode for it and this is when the choppy appears. Could be that too. I´ll try to change this parameters and see what happens. I know nothing about it… Do you? Many thanks.

Pst file:
brk_tol : .001 #Break up chordal tolerance for 'brk_mv_head'
brk_tol_m : .025 #Break up chordal tolerance for 'brk_mv_head', metric