On Tuesday 09 March 2021 12:11:40 dave engvall wrote:

> The few  times I've had different counts re' direction it has been a
> broken flex coupling to the encoder.
> Of course it could be that you are simply running out of frequency
> response. Not likely but possible.
>
> Dave

Welp, I am back to a 1 khz servo thread, having tried it up to 4 khz, the 
i5 can likely do 10 khz, but then the encoder loses track and the 
fictitious home drifts. I find the gear ratio of this lashup seems to 
prevent speeds the servo is capable of as it can move at 1800 degrees a 
minute with one leg of the bridge on full time, so my present settings 
are maxvels in the 600 degree range. that's 20 in the ini file, and 1 
khz limits me to a MAX_ACCEL of 400. And at 400, the stop actually 
tickles the opposite direction for about 4 millisecs. But not long 
enough to crowbar the supply.

The encoder in this motor is optical, and may need some pullup added. I 
need to take the other two probes out and make use of that scopes 3rd 
and 4th traces. I am getting nominally 666.666666667 counts per degree 
of BS-1 motion. More accuracy than mechanically possible. :)

Bugs?:

0. halmeter needs at least 2 more digits of display before it switches to 
an EE display.

1.Deadband does NOT work as the man page says, a 3 setting makes it run 3 
degrees past the command. There is no zero output to be seen on a scope 
as it goes thru 0 speed. idb needs that zero point when stopped to shut 
the driver off completely.

2. The idb module has almost zero effect.

3. There is an up to 5 degree offset between HOME = 0.000 and HOME_OFFSET 
= 0.000 and the switch closure which varies with LATCH_SPEED. Currently 
at 3 cuz any slower it stumbles and stalls as it moves, too much 
friction. setp debounce.0 1 in the .ini file.

4. Touch-off works crazily.  Impossible to actually touch off to zero.

Pro's:

And I'd like to publically thank whoever did the configure screen tuning 
tool, that's pure genius. Thank you very very much.

> On 3/7/21 12:54 PM, Gene Heskett wrote:
> > On Sunday 07 March 2021 14:07:33 Feral Engineer wrote:
> > [...]
> >
> >> sudo update-grub
> >
> > Wasn't in there, put it in and rebooted.

No difference.

There is also a TRAJ-THREAD defined in the ini file, running 2x faster 
than SERVO-THREAD, but I've not been able to find it running. And I 
can't addf anything to it. What does it do and What is it good for?

> > Now I am re-calibrating the servo_scale which will take an hour or
> > more. I snapshot the encoder count at 1.0 turns of the home-switch,
> > snapshot the counter at 101 turns, subtract the first count from the
> > second to get the diff, div that by 100 to get 1 turn, and divide by
> > 360 to get one degree.  Or just div by 36000. I am also suspecting
> > I'm missing a count, at g0 speed, 1800 degrees a minute, the dro is
> > losing counts, worse in one dir than the other. I *think* that's a
> > separate problem.

Which has not yet been addressed.

Thanks Dave and everybody.

Cheers, Gene Heskett
-- 
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
 - Louis D. Brandeis
Genes Web page <http://geneslinuxbox.net:6309/gene>


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