Adding Rotary Axis to Gantry Machine

Hi guys, I'm at a bit of a loss here. I wanted to add a rotary axis to my gantry machine using the 5th stepgen on my 7i76e and could not work it out when editing by hand and I was getting following errors on the new Joint 4.

So I fired up PNCCONF and made a new config which let me happily jog the new axis. It was a bit funny as PNCCONF does not know about 2.8's joint axis so the A axis was set up as Joint 3 using Mesa Stepgen 4 but hey it worked. So then I cut and paste the PNCCONF config into my working system and made the required edits so that it was based on using joint 4 and stepgen 4.

Straight away I started to get following errors. I can't see that I've done anything wrong so could somebody have a look at my hal and ini files and see if you can see anything wrong? I thought this should have been really straight forward.

In the rotary axis section of the hal file:

setp pid.a.maxerror .0005

Will cause following errors on a metric machine

andypugh wrote:

Is 1000 steps per degree right? 360 degrees/sec is 360,000 steps/sec
2uS per step/space cycle = 500,000 steps/sec limit. So that seems OK.

Did you get to the bottom of this?

Andy, thanks, no I didn't. I was hoping somebody would come to my rescue.

The steps per degree was a PNCCONF default and there was not an option to change it.

PCW wrote:

In the rotary axis section of the hal file:

setp pid.a.maxerror .0005

Will cause following errors on a metric machine

Peter thanks. I know I've seen you mention this before but am unsure of the right number. Should it be 0.01 (about 25.4x)

Interestingly I've got that set on all my axes and have not had any trouble

I should have said it may cause trouble on a metric _or_ rotary axis since there's
nothing metric about 360 degrees...

But now that I think about it .0005 degrees should be OK so this is not the issue

Ah Ha! PID.a is not addf'ed to the servo thread...

Peter, thanks I knew fresh eyes would pick up something. Sounds like that would do it! I'll give it a try this evening!

PCW wrote:

Ah Ha! PID.a is not addf'ed to the servo thread...

Peter, thanks for your eagle eye! Its perfect now thanks!