[neilw20]

I have a BLDC motor, 300W 160v with an internal encoder and hall sensors plus a 100:1 gear box.
All that works fine, complete with lost motion.
Now I have put an encoder on the output shaft of gearbox - some backlash, hence encoder on output.
Manually moving output shaft against the backlash during step response test shows the encoder is working.

Not having any success, so far, getting any movement in step response, hence it faults due following error.
How do I approach setting this up with the GDTOOL?
Do I set motor as BLDC or AC servomotor?

I need to check I have the correct number of poles set.
Once I get this working, I have 5 more motors needing encoders on the output side of gearbox, upto 1200W.

[Al_The_Man]

Does the encoder on the motor include the commutation tracks or are there separate discrete Hall sensors?
IOW does the motor still have commutation with the separately used encoder, it is very rare to be able to use a second encoder as the only feedback in a system where there is excessive B.L.
On these system the most common way is dual feedback, each on motor and final mover.
For a video on dual feedback and splitting the PID loop, there is an excellent Instructional video by Dr Tal on the Galil Motion site that applies to all systems, not just Galil.
Not sure if GD support dual feedback?
And I would not imagine you could use the GD method of encoder commutation on a non-motor encoder?
The often seen symptom of single final mover encoder and B.L. is oscillations.
Just some random thoughts.
Al.

[neilw20]

Hi Al,
Thanks for quick response (i needed it 3000 miles from home)
Motor has separate hall sensors, and 1000ppr encoders with index. (I suspect 250 lines, but my eyes are not that good)
A few days ago, I had to swap full encoders/hs assembly from a 1200W motor with broken shaft - very carefully, with 100% success.
I will now look at Galil Motion site.
Neil

[Xerxes]

Neil, did you get this working? If not, any update of the situation will be helpful for me to catch up

[neilw20]

Yes, Xerxes. Got it all going and eventually made some sense of the gdtool settings.
As the numbers are 0 to 32767 it is not obvious the scaling or where the value 1 exists in the PID scale of things.
Trial and error, leads to many errors, getting it right.
Eventually got multiple axis tracking, lead/lag wise so a straight line in multiple axis moves was where it should be.
As for the numbers used, they still don't make sense (to me)
The servos (with integral encoders) drive through gearboxes and getting the high inertia loads to perform as they should was a problem.

[Xerxes]

Thanks for update! Yes, the scale of parameters is 0-32767 which is just a 16 bit signed integer number range. PID gains are arbitrary units so scale of the units doesn't matter much.