rigid tapping fail advice and "discriminant" err

BigJohnT wrote: Hardware step generation should be able to keep up fine. Are you using a 7i76 with the 6i25?

And the most important question I forgot is what version of LinuxCNC are you using?

JT

I have 7i84 and a 7i85S daughter cards. I am using Linuxcnc version 2.7.0~pre6.

I got in touch with the developers as I was stumped and got this reply.

we are in the process of fixing that problem. A sample of gcode that shows the problem would help.
rob has a branch that takes care of the issue - but causes a few violations he hopes to look at this week.

JT

Could you give us a short gcode example that shows the discrim error? (and your ini file)

If you are energetic - you could try this branch and let us know if it fixes your issue. (it is not perfect yet)

github.com/robEllenberg/linuxcnc-mirror/...gent-improvement-2.7


sam

skunkworks wrote: Could you give us a short gcode example that shows the discrim error? (and your ini file)

If you are energetic - you could try this branch and let us know if it fixes your issue. (it is not perfect yet)

github.com/robEllenberg/linuxcnc-mirror/...gent-improvement-2.7


sam

Sam,
Attached are the ngc file I run and an image of the error it generated. Again, this doesn't happen every time, but does happen quite often.
-Tom

What is the acceleration of you spindle? I am trying to get this to trip in sim and am not having any luck so far

skunkworks wrote: What is the acceleration of you spindle? I am trying to get this to trip in sim and am not having any luck so far

Sam,

In the INI file (also attached) is this:

MAX_VELOCITY = 2.5
MAX_ACCELERATION = 50.0
# The values below should be 25% larger than MAX_VELOCITY and MAX_ACCELERATION
# If using BACKLASH compensation STEPGEN_MAXACCEL should be 100% larger.
STEPGEN_MAXVEL = 3.125
STEPGEN_MAXACCEL = 62.50

Or were you talking about VFD accel parameters? In the VFD I am accelerating from 0-3400 rpm in 1.0 second (linear ramp).

-Tom