Stepper motor stalling?

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SparksStudios
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Model of CNC Machine: ShopBot Buddy PRS-Alpha 48 w/12" Z
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Stepper motor stalling?

Post by SparksStudios »

Using Keling Tech. KL23H276-30-8B Stepper. Can do several high-speed jogs with no problem at all, then suddenly the Z Axis will stall out. After releasing the jog button and trying again, it works normally but the reference point will be way off. It doesn't happen in the same place, nor does it happen after a particular time. Seems fairly random. Although its more likely to happen after the motor warm up a little.

X and Y axis work okay, but I have had a couple of jobs go bad when one of the axis stalled at some point.

Am I experiencing an under-current stall problem? Or could it be motor resonance locking it up?

How can I tell the difference?

Thanks for any help.
Taylor

Using Mach3 with controller.
ShopBot Buddy 48 w/12" Z + 8' Powerstick and Indexer
Aspire 9.5

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zeeway
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Re: Stepper motor stalling?

Post by zeeway »

Could be several things:

1. Z axis - check for binding in its travel when machine is warm?
2. Can you switch Z motor with another axis (say X)? If the problem moves, the issue is with the motor.
3. Make sure your machine and control is well grounded (and to a common ground).
4. You may be trying to move it at a speed that is too high for motor or controller.

Angie

daniellyall
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Re: Stepper motor stalling?

Post by daniellyall »

more details will help

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esteeme1
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Re: Stepper motor stalling?

Post by esteeme1 »

I think Angie is on the right track. If it doesn't move after shifting motors you could have a wiring issue.
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garylmast
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Re: Stepper motor stalling?

Post by garylmast »

Stepper motors are cheap. Depending on the weight of your spindle, I would ask the manufacture what a replacement number is, but up-size to a larger high torque, 2-phase stepper motor. I have a very heavy 6-hp spindle and I replaced the original stepper motor with the same size and model but it went out shortly after. When I replaced it with the larger one which cost about $150, it solved all the problems.

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martin54
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Re: Stepper motor stalling?

Post by martin54 »

Couple of things, if the machine is heavily rebuilt then are you supplying the motor with the correct current lots of problems are caused by people using the wrong settings for the motor when setting up the drivers. Have you set up the motor tuning in mach3 ? Quite often people try to run the motors to fast in mach3 from what I have read because they don't leave a large enough margin of error once they have determined the stall speed or they have the acceleration & de-acceleration set to high. Check for binding along the full length of the axis as Angie says.

SparksStudios
Posts: 49
Joined: Thu Dec 31, 2009 4:37 pm
Model of CNC Machine: ShopBot Buddy PRS-Alpha 48 w/12" Z
Location: Columbus, Ohio

Re: Stepper motor stalling?

Post by SparksStudios »

I checked the wires for breakage, re-tightened the connectors, and tuned on the Mach3 motor screen for hours; and it would STILL randomly stall-out!

Thanks for the advice, everyone, but I've given it up as a bad job!

Gone and ordered a ShopBot Buddy.

It'll have the flexibility to cut large and small projects in a small footprint. Also added an Rotory Indexer, so I can expand my cutting in a whole new direction! Can't wait!

-Taylor
ShopBot Buddy 48 w/12" Z + 8' Powerstick and Indexer
Aspire 9.5

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krugshouse
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Re: Stepper motor stalling?

Post by krugshouse »

Awhile back I had a stalling problem with my X axis. Drove me crazy. I use Mach3 to run my machine. After several attempts to fix it, I was told to increase my Debounce to 5 in the General Config section. It took care of my stalling. Not sure how but it has something to do with signal noise. The higher debounce setting allows the software to determine a real signal from noise. I hope this helps, but your problem might be something different. Let us know when you fix it and what did fix it.
Good luck
Have a safe machining day

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