Planning - Bridgeport Interact 1 linuxCNC Retrofit

Yes, I just figured out the problem last night. It was my measurement setup.
I set my index pulse for 90 degrees. As far as I can tell both will work, but I think 90 degrees is more standard.

BTW it is suggested that you _do not_ reverse the output polarity by changing the PID signs
The PID component has a nasty bug with integral limits and negative parameters...

If your input scale is correct (encoders read in the right direction), and you have feedback backwards (runaway),
the easiest way to reverse the output polarity on a 7I77 is to change the sign of the scalemax parameter

PCW,

Is the scalemax parameter located in the INI file?
Im looking in the linuxcnc documents under INI and I don't see it listed.
LinuxCnc INI Documentation

If you were running away with positive PID values then reversing either the encoder or the servos is needed but not both. Most likely you will only need to reverse the encoders. At least that is what I found.

look like its:
OUTPUT_SCALE = 10
in the pncconf created .ini file

You should be able to see where the mumble.mumble.scalemax
parameters are initialized by looking at the HAL file
Note that many INI names are arbitrary so you could have a INI file entry:

[AXIS_0]
FOONBLATS_PER_SPUD = 100.0

and then in your HAL file:

setp foonblats.0 [AXIS_0]FOONBLATS_PER_SPUD

so dont expect all INI file parameters to be documented...

Thanks guys!

I have the machine testing pretty well. Tuning servos was a very steep learning curve. The more I find out what I don't know, the more I don't know! lol

Here is a video of where I have all 3 tuned to. Can't seem to get the overshoot sorted. I ended up with zero ff2/I/D

I tried many different combos. I'm sure I'll try again. My garage is a mess so you just get the monitor screen playing halscope!

Edit: btw, this was at 60in/min.

Thanks for all the help so far! I'm going to need more! :laugh:

Tuning servos