Machsupport Forum

Third party software and hardware support forums. => PoKeys => Topic started by: giantpt on November 12, 2016, 07:13:30 AM

Title: Spindle VFD feedback
Post by: giantpt on November 12, 2016, 07:13:30 AM

Hi there!!!

I own a chinese 800w VFD since 2012 and running like new, now I have a new cnc ethernet controller, I am already able to controle the spindle speed and start/stop from Mach3 but I would like to have the rpm feedback from the vfd into the mach3.
As the VFD screen shows the current rpm of the spindle, how can I get that info, which are the pins on the vfd and what time of signal is it? Pwm or analog?

Thanks

Title: Re: Spindle VFD feedback
Post by: reuelt on July 06, 2017, 04:58:34 AM

Why? it would be redundant.
Since the spindle is a direct drive (no pulleys in between), RPM should = S Speed already.

You will need a tachometer detector that can generate 1 pulse per rev. This signal is fed into the index pin of mach 3.
There are lasers and hall-effect (magnetic) detectors but spindle is too small to mount anything reflective or magnet for the tachometer circuit.

Title: Re: Spindle VFD feedback
Post by: soruud on July 07, 2017, 07:27:50 AM

As far as I know Mach3 dont use the feedback for adjustment of true spindle rpm. This is the main reason why I are going for Servomotor as Spindle. I newer got my VFD to output correct rpm to spindle by far.
You can read out the true Spindle RPM in Mach3, but Mach3 will not adjust it.

Title: Re: Spindle VFD feedback
Post by: eurohoppel on July 07, 2017, 09:16:00 AM

Hello soruud maybe it will help : https://www.youtube.com/watch?v=GFw2V2xDizM (https://www.youtube.com/watch?v=GFw2V2xDizM)