Hi all, The two nema 23 motors controlling my gantry (x) and vertical (z) threaded drives have started slipping. I have two (same) motors running belt drives on my (y) axis, one each l and r rail which seem to be fine. This is a relatively new machine, I am still in trial mode purposefully not running heavy load cuts while I dial things in. Eg. 1/4" depth of cut, 33% stepover, 1/2" carbide upspiral bit, 15 ipm cut speed, 2.2Kw water cooled spindle. There are probably no more than 15 hrs total cutting time on these motors. I'm guessing I'm just overloading the motors and its time for an upgrade to hi torque but I thought I would throw this out first. Thoughts? thanks, dkw
1) check grub screws on shaft couplers (could be slipping on the motor or leadscrew side) 2) check current adjustment on motors 3) check acceleration and max rate configs 2.2kw spindle is quite overkill and probably too heavy though
Grubs crews and shaft couplers are tight, the slippage is internal Where do I find current settings? acceleration is set at 500mm/sec2, max rate is 5000mm/min x,y and z I bought the 2.2 K spindle as a package deal on amazon great sale price and water cooled is very quiet. It is a blessing. "overkill" probably, I was looking for 1.5 K but was not finding one with er20 collet. I wondered about the weight and did not use the MASSIVE mounting block as a precaution... thanks for the quick response!
Are you using a BlackBox? the current is set with the drivers not the software, on the Blackbox there are current adjust pots. When you say "slipping" you mean loosing steps? noisy and jittery? Gary
Reduce your max speeds to 2500 mm/min. If that fixes it gradually increase it until you get problems again. Alex.
Yes, I should have mentioned black Box. I found the doc from another thread, looking at that now. Slipping is the best way I can describe what is happening. The motor feels like it is still turning internally but the shaft is not spinning. It is not a skip or stutter like jumping the belt teeth, a discernable "groan".
OK, max speeds reduced to 2500mm/min. I've just run the file I noticed the slipping, 3d surfacing with the largest bit I use a 2 flute carbide 2" dia ball end cutting 1/8"deep, 1/4" step over, 25 ipm. roughly 30 min cut time, no problems. Motors noticeably cooler. Thank You All...! dkw FYI, cutting a spruce soundboard for an archtop guitar.
Yours, I'm crossing my fingers the max speeds was the issue, I reduced them and the "slipping" disappeared.
