Stepper motors problem

[ervin]

Hello! This is my first thread, so i hope i'm posting it right.
I'm building a JGRO router but with some changes in the design (location: middle Europe) and i have some problems with stepper motors. Steppers seem to stall, but it happens at random times and in a range of rpm. Even at lower speeds there are strange sounds comming out of the steppers (sounds like worn out bearings) and they are not running smoothly. I saved the steppers from an old label printer. Are the steppers really the problem or is there something else that i missed?
Steppers: MAE HY200 2220 0141 AX04 53Ncm(75oz-in)
Drivers: PMinMO L297-8 drivers, 32V 1.4A, halfstepping
Comp: Intel Celeron 1GHz, 1.2GB RAM, WinXPsp2
Software: Mach3

[ervin]

http://www.youtube.com/watch?v=5C4W1D8T5ME&feature=g-upl&context=G2b33d3eAUAAAAAAABAA]stepper motor cnc 1 - YouTube
http://www.youtube.com/watch?v=i7MRT--vWOI&feature=g-upl&context=G21a05b1AUAAAAAAAAAA]stepper motor cnc 2 - YouTube

[ger21]

Many things can cause the problem you're seeing.

First, running an unmounted stepper on a table like in your first video will often have similar results, due to resonance. Mounting them to a machine will usually make them run better.

Now, what you are seeing on the machine could also be due to resonance. Microstepping drives will run smoother and minimize resonance, but half stepping drives are more susceptible to it.

If the steppers are dual shaft, you can add dampers that may help. If they are single shaft, you may be able to mount a damper to the screw. See this thread for damper construction info.

It could also be that your motors are just not powerful enough for this application. Try lowering the acceleration and see if it helps.

[kbisswanger]

You may also want to check the computer that is running Mach. XP has things running in the background that often causes problems. I dismissed this for quite awhile and had issues for almost a year. After disabling all the junk running in the background, I increased my speeds by over 100% and eliminated the "hitches" or missed steps. I think there is a document on Machs website that details how to optimize your computer. This may not be the issue but it is something to check out.

Keith

[ervin]

I have done some more tests on the machine. Mach3 test completed ok, so I tried running a different motor at very low speed (one revolution/minute) and it still had lost a few steps. Because it's happening on all three axes i think the problem could be the DB-25 port which is integrated on the motherboard. I'm going to try installing an expansion card if i find one somewhere.
I apologize for my bad terminology...

[ervin]

It's definitely worth trying to modify the system before spending € on the hardware. But as I remember from the manual Mach3 gives special instruction only for Win7/Vista. Anyway, I'm going to double check.

[ger21]

I believe he was referring to this.
http://www.machsupport.com/downloads...timization.txt

[ervin]

I reinstalled everything, optimised XP, updated the drivers with no improvements... then i saw somewhere in the forum about sherline mode. I don't really know what it does but i tried it and it seems now to run as it should. Of course i didn't test the machine in full yet but the improvement is great.

[OCNC]

If you still have trouble bypass the breakout board.

Chris