Hi there, I've been lurking around this sight for a couple years now, and figured it was time to finally actually post a question. I purchased a ModularCNC Mini-mill kit off ebay a couple years ago to play with while I got around to building my own 3 axis router. Here are the stats to everything I am running.
Vextra PK266M-01A .9 degree steppers 166 oz
Item # PK266M-01A, Stepping Motor on Oriental Motor U.S.A. Corp.
Univelop 5 Axis Driver
http://www.cncgeeker.com/images/manu...rCNCGeeker.pdf
1- 24V 25Amp PSU for the steppers
1- 12V 10Amp PSU for the BOB & cooling fans
ACME leadscrews 1/2-10 single start
I got the 5 axis driver because I got a MUCH better deal on it compared to the 3 or 4 axis models, which gives me 2 spare driver cards. I plan on upgrading to 5 start screws once $$$ allows. Ok, now that I have given a little background here is the issue.
Before I get into this, I just want to say, I KNEW NOTHING about steppers when I bought these....now after countless hours of research I think they are the problem.
When I have these steppers and electronics hooked to the ModCNC minimill, I was only able to produce 20IPM with no load(15-18IPM while cutting wood, very shallow cuts). I didn't think this seemed very fast at all, but because of only having 6"x4" of travel it wasn't too bad. Now that I have moved these steppers/drivers to my new router which has 20"x16", it seems SO slow! LOL. My new machine is WAY easier to turn the leadscrews manually, it is VERY smooth, but yet I can't get any more speed out of the machine.. Still stuck at 20 MAX. I have tried playing with all the settings in MACH3, and switching between all microstepping settings on the drivers, and full step gives the best speed/torque without stalling. I see that my motors seem to have a WAY WAY higher inductance than many other motors on the market...is this where I am losing my speed??? I've read that higher voltage=higher speed. Using the MAX voltage calculation of Inductance sqrt*32= 228volts.....Yet these motors get REALLY hot at 27volts(24v PSU cranked up to max), so going to a bigger PSU, 36V is driver max, seems like it would just create MORE heat and probably won't give much more speed.. Am I totally off on this? I basically guessed when I bought everything b4, and looked at prices more than stats of everything.. Do I need to buy new steppers or am I setting something up wrong?? I'd like to get up into the 50IPM range while cutting... I don't want to pick the wrong equip again, so if someone could suggest motors and/or drivers with reasonable pricing that would be great. Ok, I guess I am done rambling on, so THX to anyone that can help..