Hi,
I have a somewhat unusual RepRap config - I have added a hot end to my homebuilt CNC router (600 x 400 x 100mm).
The machine: XYZ axes TB6560 driver chips driving 300oz-in NEMA 34 24v steppers, hot end standard RepRap. RAMPS 1.4 electronics.
The main practical difference in driving these is that they require a 90 uS pulse dwell on CLK (STEP) [Delay stepper high = 110 uS] and a re a little slower in max speed/accel than a standard Prusa [9mm/s 15mm/s2] due to the much larger mass of the carriage.
All works well, except that it occasionally drops a string of pulses on the Y axis (once or twice in a 20 minute print).
I have looked at the many posts on tuning, and tried fixes based on the advice. To no avail.
Looking on the scope, the Y pulses actually stop early, i.e.not enough pulses to step the required distance, rather than pulses being dropped by the driver chip/motors.
I'm wondering whether altering the Move Cache Size from 16 to 32 might help.
Any comments or suggestions?
Thanks
Richard
