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Step Loss -help please
« on: March 19, 2009, 09:32:57 PM »
Hi everyone,

I converted a Denford Triac to Mach3 a while ago, but due to moving house have only just got round to serious use.  I'm having a problem with step loss in the Z axis.  It seemed fine on basic machining, but I've now tried some 3D engraving, and I'm loosing steps.  The program starts OK, but the Z axis runs up in Z so after a short while (actually about 10,000 lines of code -so quite a lot of movements) it's cutting in fresh air.  I thought I was trying to move it too quickly, but even dropping acceleration to 10 and speed to 500 it still does it (I'm in mm by the way).

I'm using the original stepper motors, with drives from Arc Euro (set to 8 microsteps) and they are run through a C11 board from CNC4PC.

I can't help thinking I'm missing something obvious, but don't know what.  Hopefully one of you will point me in the right direction.

Thanks

Kevin

Offline Hood

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Re: Step Loss -help please
« Reply #1 on: March 20, 2009, 03:26:29 AM »
Try increasing the Pulse Width on motor tuning to 6 or so if you dont have it that high. It is quite unusual to lose steps on a Z Axis going down the way, it is much more common in the Up direction as you are fighting gravity so I am wondering if there is a possibility that it is your cutter moving in the holder?
Hood
Re: Step Loss -help please
« Reply #2 on: March 20, 2009, 05:16:30 AM »
I'm fairly sure the cutter isn't moving, it's only cutting modelboard and I can't push the cutter into the collet by pushing against it.  Pulse width is 5, the highest I can go to (must install the latest software version).  This seems to work fine with X and Y though.  I can't work out why the error is in one direction, and I agree it's the wrong direction.

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Re: Step Loss -help please
« Reply #3 on: March 20, 2009, 06:48:44 AM »
5 should be fine with these drives, definitely no offsets in your code?  Try just Z moves repeated for a while and see if it goes wrong.


Hood

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Re: Step Loss -help please
« Reply #4 on: August 24, 2010, 02:30:35 PM »
hi
I having similar problem
with 3d machining I have x and y axis moving to -
after 10 000 lines losing about 3mm in x and y less but y make much smaller distance
i tray again and again and changing a parameters but every time same error
Re: Step Loss -help please
« Reply #5 on: August 24, 2010, 06:07:17 PM »
adding a 0.1uf ceramic cap to ground on all your inputs seems to cure this odd creeping on the axis.

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Re: Step Loss -help please
« Reply #6 on: August 25, 2010, 09:04:57 AM »
Hi
thanks for reply
I think my Frequency Controller making problem
when I turn him off everything is ok
I dislocate him but still making problem probably wiring too close
any suggestion
thanks
Re: Step Loss -help please
« Reply #7 on: August 25, 2010, 10:32:09 AM »
Hi everyone,

I converted a Denford Triac to Mach3 a while ago, but due to moving house have only just got round to serious use.  I'm having a problem with step loss in the Z axis.  It seemed fine on basic machining, but I've now tried some 3D engraving, and I'm loosing steps.  The program starts OK, but the Z axis runs up in Z so after a short while (actually about 10,000 lines of code -so quite a lot of movements) it's cutting in fresh air.  I thought I was trying to move it too quickly, but even dropping acceleration to 10 and speed to 500 it still does it (I'm in mm by the way).

I'm using the original stepper motors, with drives from Arc Euro (set to 8 microsteps) and they are run through a C11 board from CNC4PC.

I can't help thinking I'm missing something obvious, but don't know what.  Hopefully one of you will point me in the right direction.

Thanks

Kevin

Kevin,
 Just a thought, I was seeing the same thing, it turned out to be the collar on my servo motor was slipping and causing creep in the Z axis. You might want to check it if you are using a clamp type collar

Mike

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Re: Step Loss -help please
« Reply #8 on: August 25, 2010, 01:38:49 PM »
Might want to look into getting a line filter for your VFD.
Hood

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Re: Step Loss -help please
« Reply #9 on: August 25, 2010, 01:50:24 PM »
Whats your power supply's current like?  And the current setting on your driver?
I was losing steps on my mini mill because I was trying to power it off a 1 amp laptop power supply lol
Mr. Creosote