Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: cdntoolmaker on March 05, 2010, 03:49:25 PM
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On my Taig mill when jogging my Z axis using the up and down arrow keys the motor intermittently freezes almost like it is binding and sometimes the up goes in the minus direction. Also the Z axis will not start moving unless it is jumpstarted by hand. Does anybody have an answer for these problems or any suggestions? Just a final note about the binding. When the controller is off and no power is to the motor I can freely turn the headstock up and down using the hand crank. I am having no problems at all with X & Y axis. Please could someone help me.... ???
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Sounds like noise issues or possibly loose connections on the step and dir connections.
Hood
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Hi Hood,
Thanks for the responce. I can check for loose connections, but what do you mean by noise? How do I find and correct it?
Thanks,
cdntoolmaker
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Electrical noise, basically interference on the wires. If you have any higher voltage wires running beside the step/dir wires they could cause noise in the step/dir wires and make the drive think its getting signals. Low voltage wires such as step/dir should ideally be shielded to help protect from noise.
By the sounds of it though its more like a bad connection.
Hood
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I agree with Hood. It is most probably a loose connection by your description.
Daniel
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Hi guys,
Thanks for the suggestions and information. Over the weekend I went through each connection and everything seems fine, there were no loose wires. What I did notice was when the up and down keys are pressed you hear the hum of the motor trying to move and when you give the hand wheel a touch or a slight nudge it starts to move. It is the same going up or down and at all areas of the column not just one spot. If I do this a couple of times it seems to warm up so to speak but then all of a sudden it stops engaging again when the button is pressed unless you give the hand wheel a nudge again. It almost seems that it is not getting enough initial torque to get it moving because when it's moving it sound and feels smooth all the way up and down the column.
Any ideas of what I can do or check next. ???
Thanks,
cdntoolmaker
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Sounds like the drive may be bad, can you swap out the drive for one from the other axis and try? If the Z has a separate power supply from the other axis check to see its not failing under load.
Hood
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Accel rate possibly too high ?
Would be similar symptoms ?
Check tuning ?
RC
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I don't think its the accel rate because I have been running this Deepgroove1 Taig for almost 4 years and it just started to happen. As for swapping out the drivers I think that's a little advanced for me as I am a toolmaker not an electrician. I can check voltage and for loose connection's but that would be the extent of it.
cdntoolmaker
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Just double check to make sure that the accel is what you originally had. However if the motor was stalling you would hear it I think.
Hood
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All three motors are the same size. Their settings are very close when you look at the graph and it does run smoothly after the initial nudge to get it going.
cdntoolmaker
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When you try to move the Z do you hear its making a squealing kind of noise?
Can you swap a drive from the X and try it on the Z and vice versa?
Hood
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If its been running that long, and you've changed nothing, looks like either electronic/electrical or possibly the Z ways and mechanism might need cleaned / lubed even though it operates smoothly by hand.
I dont understand it changing direction though.
And like Hood said, missing steps/ stalling would make a bit more racket than just a humm..unless maybe you were super micro stepping.
Not too difficult to switch wiring just to check, mark the wires carefully and take notes.
Good luck,
RC
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Hi guys,
O.k , I'll try your suggestions and take notes. Hopefully a little luck will be on my side. I'll let you know what happens, good or bad.
Thanks for all the help so far.
cdntoolmaker
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If you push it and it starts moving then, it sounds like only one phase of the stepper is working. Either a bad connection of the motor wired to the drive or a bad drive. Also, maybe a bad connection on the drive board itself.
Daniel