motor skip on retract

all was working perfect, and I swap over from Ramps 1.4 Mega2650 to Radds 1.5 Arduino Due (genuine not copy)

everything seems perfect on first flash except when retracting, extruder motor skip badly, no current changes from ramps to radds, had a look in the firmware max speed was 50mm/s on extruder so I reduced it to 25mm/s and it all seems good for printing except at the start of the print wher it retract before print, which I dont know why, never did it before, and when using filament change option, it skips very bad, I ended up pulling out the filament and feed it by hand instead, other than that, it prints beautifully and more quiet, seems a little faster

also I have no way of controlling from repetier host, just from lcd alone

its running latest repetier firmware

Edited 1 time(s). Last edit at 07/30/2016 06:05PM by deaconfrost.

think I found the line in configuration.h to change it from 40mm/s to 30mm/s

can't try it yet as I'm in the middle of a 3 hours print

all sorted, how I missed the buadrate changed in the host... lol

extruder 1 is skipping again, anything over 25mm/s the motor will skip, no problem on extruder 2, happens usually on undo retraction on normal retract or tool switch

adjusting current on stepper driver makes no difference, is it the driver or the motor? it is even running on 1/8 stepping but it doesn't seems to be getting the torque.