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Author Topic: Servo for lathe spindle ?  (Read 18180 times)

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Offline Dan13

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Re: Servo for lathe spindle ?
« Reply #40 on: September 30, 2014, 07:09:03 AM »
You can try connecting the signals directly, but usually encoders output weak signals so a line drive would be preferable:

http://www.cnc4pc.com/Store/osc/product_info.php?products_id=337&osCsid=53062d4f014880b38fc29ac5affa980c

Dan

Offline Dan13

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Re: Servo for lathe spindle ?
« Reply #41 on: September 30, 2014, 08:10:19 AM »
Forgot to say. You can measure the output signal from the encoder, if you see it's a good 5V then a line driver may not be necessary.

Dan
Re: Servo for lathe spindle ?
« Reply #42 on: September 30, 2014, 08:17:54 AM »
thanks Dan,i will measure tonight and see...
Tasbiz

Offline Hood

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Re: Servo for lathe spindle ?
« Reply #43 on: September 30, 2014, 02:53:54 PM »
Some drives have two sets of outputs for the encoders,  pass through and buffered, not sure if yours have that option?

Hood
Re: Servo for lathe spindle ?
« Reply #44 on: September 30, 2014, 04:53:03 PM »
 Dan13: I have measured: 3.6Volts btween A+ A-  B+ B- and Z+ Z-.In the drive with the problem only difference is A+ A- is 1.5V.Opened the drive.Looks repairable.I will check more tommorow...
Hood: Unfortunately mine does not have a pass through...

Thanks guys..I feel you are still with me...
I appreciate that...a lot!

Tasbiz
Re: Servo for lathe spindle ?
« Reply #45 on: October 01, 2014, 04:49:48 AM »
 I think that i found it!!
There is a IC that is a line driver which causes the problem.I have ordered it (1,1 Euro ) and hopefully is going to make the driver ok again!!
 Tasbiz

Offline Dan13

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Re: Servo for lathe spindle ?
« Reply #46 on: October 01, 2014, 08:54:49 AM »
Sounds good!

Dan

Offline Hood

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Re: Servo for lathe spindle ?
« Reply #47 on: October 02, 2014, 04:22:17 AM »
Had to replace a line driver in one of the Allen Bradley drives I have here, was my own fault, had wired up the encoder wrongly and had connected the 9v rather than the 5v (smart encoders require 9v but this was normal incremental) and not only blew the line driver but also the encoder. I hopefully wont be making that mistake again :D
 Hood
Re: Servo for lathe spindle ?
« Reply #48 on: October 03, 2014, 10:42:30 AM »
Hi Hood Dan13 and everybody!
I have to HAPPILY report that problem is SOLVED!!!
The drive is back to normal after i changed the line driver chip!!!
Very happy with it!
Another question: I am trying to tune the servos with CSMIO A and even though i have tuned them with the drive and everything is OK when i connect them to the csmio they start to move in one direction veeeery slowly.I have tried to alter the rigid hold values but this is not stopping.They jog ok but when i let the jog buttons they are back to singing-moving very slowly towards one (always the same direction).I tried to use a DAC value in CSMIO plugin and that seems to correct it but not 100%.I measured 200mvolts on the analog output.How can i correct that?Can you help please?
Tasbiz

Offline Dan13

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Re: Servo for lathe spindle ?
« Reply #49 on: October 03, 2014, 11:07:47 AM »
Glad to hear it was an easy fix for you.

The DAC offset is the setting that should fix your drift issue. Hood is more experienced with analogue, and I believe he will be of greater help as to why it doesn't solve your issue completely.

Dan