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Author Topic: Lathe servo spindle setup/cal issue  (Read 2419 times)

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Offline strud

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Lathe servo spindle setup/cal issue
« on: October 11, 2013, 07:42:35 PM »
So I now have my lathe with servo spindle running in some fashion although there is an issue I can't resolve in the way I would expect or that makes sense. Iam running an ESS and the latest version of MACH3 and all drives are running in step and direction command interface.

So when I configure this servo to operate as a rotary axis with the steps per unit I calculate, all works well. The servo is setup to accept 8192 steps per revolution with the appropriate 'electronic gear ratio' to compensate for the 40:56 reduction of the timing pulleys. So no problems there !

However, when setup as a spindle in MACH3 I cannot use the same steps per unit. I guess that I don't really understand what this value means. So rather than using 8192 counts/rev (I have assumed this is what it means ie counts per rev) I have to used approximately 9000 counts per rev to get the actual spindle to the correct speed.

So in summary, the whole system works fine when the servo spindle is setup as a rotary axis ie counts per unit all work as expected etc. There seems to be something wrong or I'm doing something wrong when setting up to run as a spindle.... ???

Also, I have tried running the spindle cal tool and when I press cal, the spindle gets stopped immediately.

Any help most appreciated !

CS

Offline Hood

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Re: Lathe servo spindle setup/cal issue
« Reply #1 on: October 12, 2013, 03:40:11 AM »
You dont use spindle calibration if it is a step/dir servo.
What you do is make sure the plugin is set for Step/Dir spindle. Then in Motor tuning you set your pulses per rev (8192 ? )  and your Velocity (max RPM of the motor) and acceleration (probably around 20 or so.
The other thing you need to do is go to Config menu then Soindle Pulleys and set the max RPM to the same as you have in Motor Tuning.
Hood

Offline strud

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Re: Lathe servo spindle setup/cal issue
« Reply #2 on: October 12, 2013, 07:23:20 AM »
Hi Hood

I think that I've got everything as you've described except for the two max speeds being the same.

Would be odd if that is the issue but will give it go tomorrow.

Thanks

CS

Offline Hood

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Re: Lathe servo spindle setup/cal issue
« Reply #3 on: October 12, 2013, 07:40:00 AM »
I think it will sort your problem ;)

Hood

Offline strud

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Re: Lathe servo spindle setup/cal issue
« Reply #4 on: October 13, 2013, 07:10:34 AM »
Thanks Hood !

Worked as you suggested, all sorted now with spindle speed and resolution spot on.

CS