Biesse Rover 322 MESA retrofit

I would tend to disagree on the output scale. ideally it should be the machine
velocity (in machine units per second) at 10V, so 10 makes senses if the maximum
speed is 10 mm/second (at a full scale 10V output)

The reason to use this scaling is:
1. FF1 == 1.000
2. PID values are the same for inch and metric machines
3. All the PID values are in normal engineering units
for example, a P value of 1 means: correct the velocity
by 1mm/s for a 1 mm position error

Thanks for input Peter! I'll update the limits tomorrow and test again.

The drives are Yaskawa Servopacks and may well be velocity mode drives. How do I tell for sure?

Can I calculate the correct OUTPUT_SCALE from maximum speed at 10V? IE 75 m/min = 1250 mm/sec?

Also; Having you here; RS-485 control of the VFD should be possible through the 7i77 and it's sserial port, right?

They have to be scaled:

OUTPUT_SCALE = 150
OUTPUT_MIN_LIMIT = -150
OUTPUT_MAX_LIMIT = 150

if I set the limits to +- 10, The 7I77 output voltages would be limited to
10/150 or +- 0.6666V

So in theory I should set OUTPUT_SCALE to 1250 and FF1 to 1.000?
(given that my machine is spec'd at 74 m/min)

The servo period reflects the crappy laptop I'm using for testing. Had to crank up the servo period and watchdog timeout to keep the link going. Will replace with a proper computer. Is the servoperiod biting me here?

I've been trying to follow your guide, but struggle as I don't get the error messages needed for the tuning. Also; I believe the acceleration for all axis needs to be considered before starting tuning, not just the jog speed. I mistakenly put in a way high number (copied from the original XNC config) and think I got lucky not stripping teeth of the servo gears. Quite violent.

tom_no wrote:

So in theory I should set OUTPUT_SCALE to 1250 and FF1 to 1.000?
(given that my machine is spec'd at 74 m/min)

Output scale would normally be about 10% higher than the maximum design speed
This is to allow "headroom" so the PID can still command a higher speed even at the
machines maximum design speed.

Another way to say this is that at 10V, the machine should be moving about 10%
faster than its design speed

Makes sense, can't regulate when already at 100%.
That puts me at a outputscale of 1375 then.

Updated my configuration today and the machine immediately ran smoothly. Brings a tear to my eye.

Thanks Peter!

OUTPUT_SCALE = 1375
OUTPUT_MIN_LIMIT = -1375
OUTPUT_MAX_LIMIT = 1375
FF1 = 1.000


Video, in case it did not happen?