Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: bwprice100 on December 12, 2006, 04:26:33 PM

Title: Axis position feedback
Post by: bwprice100 on December 12, 2006, 04:26:33 PM

Hi All

I just joined the site; I am living in the UK and am awaiting delivery of the following system
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&ih=016&sspagename=STRK%3AMEWN%3AIT&viewitem=&item=260062146347&rd=1&rd=1
I am hopping to fit it to a ‘Taylor Hobson engraving machine but would like to ask the following general question.
Generally speaking how does the Mach software handle axis position feedback; I have done various searched on the forum but to no avail.

Any help very much appreciated.

Brian

Title: Re: Axis position feedback
Post by: Chaoticone on December 12, 2006, 05:01:16 PM

Hey Brian,
    I'm not sure exactly what you are asking. You can install encoders and set up some DROs on your screen if that is what you are asking. Mach doesn't support closed loop just yet. You can use the actual position (encoders) and the Mach position DROs and have it throw a diveation error.


Hope this helps,

Brett

Title: Re: Axis position feedback
Post by: Chip on December 12, 2006, 08:08:54 PM

Hi, Brian

Your system above is Stepper motor there is no feedback.

You can setup Home switches and reff. to a start Position to calibrate when needed.

Hope this Helps, Chip

Title: Re: Axis position feedback
Post by: bwprice100 on December 13, 2006, 03:07:14 AM

Thanks for the quick replies guys.

I read the section on home position switches to give the initial starting position but was really asking more about positional feedback during operation. One way is via the use of a closed loop system (not supported) but I have also seen systems particular to stepper motors where a pulse or pulses are generated per revolution of the motor, a sort of poor mans encoder but I assume this is not supported either.
Thanks again for the answers and I can’t wait to get cracking on this project.

Thanks Brian

Title: Re: Axis position feedback
Post by: Hood on December 13, 2006, 03:59:32 AM

Ron Rogers does a breakout that will error out if an encoder and the pulses Mach sends out dont match up. Not really closed loop but as near as you will get at the moment.
Hood

EDIT
 forgot to link to his site, www.rogersmachine.net

Title: Re: Axis position feedback
Post by: bwprice100 on December 13, 2006, 04:40:57 AM

Quote from: Hood on December 13, 2006, 03:59:32 AM

Ron Rogers does a breakout that will error out if an encoder and the pulses Mach sends out dont match up. Not really closed loop but as near as you will get at the moment.
Hood

EDIT
 forgot to link to his site, www.rogersmachine.net

Thanks for the link Hood; this looks promising and as you say could be a good compromise.

Brian