# 3-axis Cnc Stepper Problems



## Braren (Feb 20, 2016)

Hi guys, 

This is my first time posting, I like the articles here, hopefully someone can help me out!

I'm converting my Harbor Freight 1-1/2 HP 3 axis milling machine into a CNC.  I'm using 269 in-oz Nema 23's from China, cheap, $85 for 3 of them.  The problem I'm having is that the motors don't have enough power/are dying on me.  The one I was using on the Y-axis completely went out, I have it detached from the mill, and when I send a command to it it just buzzes as though it's trying to turn, but I get no spindle rotation at first, and maybe if I'm lucky it'll get a few turns out and then go back to no spinning, just buzzing.

I was just running another cut after replacing the motor and now my X axis motor stopped turning, I think I may have burnt that one out too...

Running GRBLshield and 24V 15A power supply.

Here are the questions I have.
1.)  Has anyone had success using this type of motor for a similar load requirement?  Maybe I should just use more powerful motors...
       -I use 1x microstepping so that I don't miss steps

2.)  Could my mounting be what is killing the motors?  My motor mounts are pretty sketchy right now (I was waiting to have my cnc semi-operational before making good mounts) I think that too much of the motor's weight is sitting on the spindle, this could make the motor work way harder than it needs to.

Thanks for the help!


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## jumps4 (Feb 21, 2016)

we need a lot more information to be of any real help
what HF mill do you have
do you have ball screws
are your controllers set to the right amperage for the motors you have?
are the motors getting hot
what controllers are you using and at what voltage
are you direct driving or using a reduction?
and as always pic help a great deal
Steve


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## cozmogeek (Feb 21, 2016)

It doesn't move correctly when off the mill? That's bad. Either the driver isn't sending enough power or maybe it's trying to turn too fast?


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## Braren (Feb 21, 2016)

Thanks for the replies guys, I was able to get it working again.  I don't think my steppers are rated for much side load, so I pulled apart the locked up stepper, lubed it up, etc, reassembled, and now it's running smoothly again.  I'll just try to be more diligent about keeping as much of the motor weight off the spindle as possible.


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## cozmogeek (Feb 21, 2016)

I had a stepper on my 3D printer fail like that actually. It locked up and wouldn't move. I turned the shaft with pliars and it unstuck itself and has been fine since actually.  I have spares just waiting for it to give me trouble again.


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## Al-Hala (Feb 27, 2016)

Braren said:


> Thanks for the replies guys, I was able to get it working again.  I don't think my steppers are rated for much side load, so I pulled apart the locked up stepper, lubed it up, etc, reassembled, and now it's running smoothly again.  I'll just try to be more diligent about keeping as much of the motor weight off the spindle as possible.


Alas, you may find that that stepper (if by pulling apart you mean you took the rotor out) is weaker than it was before. Steppers are magnetized assembled, and can lose a large portion of their flux density if disassembled; my concern would be if it was marginal before, it may be even more so now.

Mariss Freimanis of Geckodrives result of doing the same


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