ATC Project - Debug phase

I think I read an older post on this board to the effect of: "Building an ATC is easy.  Programming is the hard part."

They weren't kidding.  I guess the only hard part of the actual build was finding a good quality planetary reducer for cheap.  Everything else has been relatively uncomplicated.

If we can come up with a reliable control scheme that works reliably and doesn't require a geneva drive or encoder, that'd lower the bar for quite a few people.

And when I say "we", I mean "Andy & others" while I do what they tell me.

tommylight wrote:

-Use "carousel" component as is

 

That's the current problem.

The new 'counts' mode seems to be working...ish.  At slow speeds it's reliable, but starts acting up if the speed is increased - at least for me.

And you don't need a pocket sensor.  Carousel component keeps track of position once it's homed to a single index sensor.

You could probably 3D print tool forks but I'd like to see a bunch of testing before I trusted them over injection moded forks.  Same thing goes for mechanical bits with weight on them.  I'd be concerned about cold creep over time.

While you're feeling ashamed, can you figure out why the carousel acts up at higher speeds?

And give your dog a pet for me.

Closed loop stepper, no feedback to LCNC.

It's not losing steps, and carousel.comp doesn't lose track of position.  Works fine at speed '25' (whatever that means), but if I turn it up past that it starts making whole extra turns before settling on the right pocket.  i.e. instead of one increment moving from pocket #1 to #18 it will rotate 3 complete revolutions plus one increment.

And the faster I set the speed, the more extra revolutions.  Happens in both directions.

BTW, I think the speed is probably based on stepper counts per rev and not time-based, but I'm not sure.  I just know that "25" is slow - like 1.5-2 seconds per pocket.

I'll try to get something video'd tonight.  I don't have a YT account, but I might be able to persuade the spouse to let me upload something to her account.

I was just re-reading Andy's carousel.comp (the latest on github) and noticed that there are three speed setting pins
fwd-dc
rev-dc
motor-vel

I have fwd-dc = 25, rev-dc = -25, but nothing set for motor-vel.  I think I'm going to fiddle with that tonight and see if setting motor-vel to some value changes anything.  Now that I read it (again), it's a little unclear which one to use to set the speed:

fwd-dc         "Velocity or duty cycle when forwards rotation is desired"
rev-dc          " Velocity or duty cycle when reverse rotation is desired"
motor_vel    "The duty-cycle or velocity to drive a DC motor or stepgen"

Ok, so motor-vel is an output.  No low-hanging fruit there.

Noticed that carousel had 18 sense pins in halshow.  Checked the hal file and sure enough, I had

loadrt carousel ... num_sense=18

Figured it couldn't hurt to fiddle around and dropped that down to 1; I've only got 1 pocket/index pin, right?

Then I start getting this:
 

and LCNC starts locking up and getting really laggy.  Have to shut it down, can't really do anything (jogging, mode selection, MDI).

Edited hal again to num_sense=18, and the error goes away.

Tried with num-sense=0, error gone.  What the heck?

Also... narrowed the continuous rotation error down to the following speeds:

fwd-dc=28, it acts as intended (one pocket)
fwd-dc=29, it rotates at least one extra turn
rev-dc=-31, ok
rev-dc=-32, extra rotations

Odd.