[zerodegreec]

I hope to sort out my festering problem with stalling motors. I made this video to help describe what I have going on, and if I in fact have a "problem" or if my machine is just at the peak of its ability. Nuts and bolts of it:
X and Y motors are KL23H2100-50-4B
Z Motor is KL34H295-43-8A (Wired Bipolar Parallel)

X/Y Driver is KL5056D
Z Driver is KL8070D

Both drivers set for 1/8 microstep, Half Dynamic standstill.
X/Y motors are rated at 5A and my drivers are set for 4.9A
Z motor is rated for 6.1A and my driver is set for 6.1A

Motor Tuning (setup in mm/min):
X and Y are at 1800 Velocity and 400 Accel
Z is 2000 Velocity and 400 Accel

If I move my X/Y up to anything over 1800 I get periodic stalling. If I go all the way to 2600 it is guaranteed to stall in rapid moves 80% of the time. Never had Z stall out.

So is this just the limit of the system I have put together? It is not the end of the world as I don't cut anything at the moment above 1000mm/min but I would like to know for my own satisfaction that I dont have something wrong. Some systems advertise advertise 300 to 1000ipm rapids, that's 7620 to 25400mm/min!!!! WOW I am way off that number.

http://www.youtube.com/watch?v=jjFofxlR-To

[Dr.Fiero]

Wow fisheye lens! I'm dizzy now. :wee:

Yep - sounds like you've just exceeded what the motors are happy with. I just went through the same thing.
I just kept backing the speed down (accel had little effect) until I could run end to end over and over with no stalls at all.
I just opened up notepad and wrote out a G0 Y0 Y5.5 Y0 Y5.5 then copy/pasted it about 100 times. Then sat back and watched!
(and again for my X, my Z was fine)

Oh, I left a dial indicator attached to the base, with the table bumping into it, then as long as I always saw the needle land back in the same 'zone', I could be pretty sure I hadn't missed a stepper fart.

(BTW - where are you? I'm near Vancouver)

[SCzEngrgGroup]

With steppers, you must derate performance. Find the maximum velocity and acceleration at which it appears to perform reliably, then back off by 30-50%. If you try to run them at the limit, they WILL fail, by either randomly losing steps, or stalling.

Regards,
Ray L.

[zerodegreec]

Thanks guys, Yeah the gopro is hopeless for this kind of thing, should have used my phone sorry about the fish eye.
I am in Cochrane Alberta, relatively speaking not that far from you. Need some way oil? I bought a 5gal pail a year and a half ago (smokin price).

[hp84117]

You might be hitting the limits of your computer rather than the limits of your motors and drivers.

I was experiencing similar issues to what you show in your video. After months of fiddling I opened the task manager to see what the CPU utilization was. I found that every time an axis stalled, the utilization hit 100%, or the other way around. There was one process that was consuming a fair amount of bandwidth and after removing that, the problem was gone. I have since upgraded to a faster computer and a real stepper driver, and haven't run into that since.

Another way to test to see if the computer is the problem is to set your drivers to no micro-stepping (1/1) and see if the system runs eight times faster before stalling.

Alan

[Kenny Duval]

I had the same issue on my machine running on the old P4 PC that came with it. I dropped a new PC on it and the issue disappeared. I was able to double the speeds the machine will run reliably. Haven't has a single stall since. Your machine also has the same sound mine had. It's much quieter now than it was running the old PC.

[hoss2006]

You aren't experiencing anything unusual with running with the stock screws.
There's much more friction and higher tpi than compared with running with ballscrews.
The faster you run steppers the weaker they are.
As you can see in the video below the best I got reliably with the stock screws and old pc was 55 ipm (1400mm/min)
I agree with the others that a good pc can help, others have reached 100ipm with stock screws, I got the same thing you are experiencing peaking at 100.
You won't get the reliable 200-300 ipm until you switch to ballscrews.
Hoss