I’ve been having a problem with Z axis on a BP series1 milling machine during reverse in tapping cycles.
The stepper on Z stall anytime the feed is set for more than 13 IPM. It seems that gcode calls for more acceleration than the motor can provide.
I have changed motor tuning options in all sorts of way and I can overcome this problem by setting the acceleration really low to 0.4 IPM with velocity of 100 IPM.
Here are my equipment specs:
Series1 BP mill
NEMA42 1150oz 8-wire 1.8deg steppers wired in parallel for most power
80V supply on each axis.
Microstepping driver set for 9.5A and 10 steps (2000steps/rev)
Ballscrews with 5TPI
Motor settings:
velocity 100IPM
Acceleration 4IPM
10000 steps per rev (2000 steps/rev * 5tpi)
Looking at the motor chart, it looks like I should be able to run about 80 IPM (400rpm/5tpi) and full power. In motor tuning screen I can set the velocity to max of 150IPM with acceleration set at 10IPM and have no trouble moving the axis.
So why is the stepper stalling on the retract part of the tapping cycle with federates exceeding 13IPM?
feed rate but without any time for acceleration and I think this is what stalls the stepper.
Thisngs I tried so far:
swapping harware channels (motors, drivers) and I still get the same issue. Although when I sawp Z with X, it seems to have higher limit as to at what feed rate in stalls. Also, I believe the reason the stepper is stalling in retract portion of the cycle is due to more load due to gravity. I checked out the machine and it is not hanging up or binding in any way.
I also changed microsteping to 5 from 10 I am not sure if it made a difference.
Tried Shirline pulsing, no difference.
Could it be the way gcode calls for feed? It seems to want full feed rate without trying to accelerate the motor, maybe this is how it needs to be, but I don't have this problem when I'm milling in x-y with higher feeds. I included TAP file with the tapping cycles that I'm trying to do and also my XML.
I would appreciate any input at this point.