Quantum and Z step processing error? (using quantum 2-6 hours daily)

[LJJ]

I've been running quantum since your release. I've seen a tremendous increase in the smoothness, and ultimately a total process time reduction. I use it routinely with 2d contouring, and also 3D finish milling. Mach 3 had jerky behaviour on one particular part at 35 ipm.  I can run the same file in Quantum at 75ipm and it's actually smoother that M3 at 35ipm. Awesome improvements.

My issue has stumped me for the last month... I've tried everything I can think of and no change. Here is the problem.

When using the herm. Curving feature, if the cutting speed (ipm) reaches 60ipm or greater on the X or Y axis, the Z axis will no longer downfeed. The error presents itself when g-code line interpreters the Z axis movement script. The line is read, and the motor responds with a short high frequency "beep" as if over greatly accelerating and missing all steps. It only does this on a down feed command line.... if left to run after the beep and associated null Z movement, when the next Z line to raise the mill is run, it will correctly process the Z line and the mill will raise.

I have changed the programmed Z plunge rate to all low and higher ranges of feed, I have also re-tuned the Z axis motor parameters for higher and lower acceleration, and also higher and lower max speeds (sps) Neither changed the behavior.

The only way to keep the Z axis feeding down while Herm Curving is on is to reduce the overall cut speed to below 60 ipm. I have tried the herm curve setting # from .001 up to 1000 and don't see a change in the Z issue.

I am running 8000 steps per inch on X and Y and 20,000 spi on Z. The problems occurs with Jerk on or off. When on, I have it set to 300 and my acceleration parameters under motor control are extremely high (.05 sec ramp) The system jog is bordering on jerky, but code runs well with the jerk on smoothing it out.

If you have anything that I can do to fix this, please let me know. I can physically run the parts up to 150 ipm with Herm Curv. on, but the Z stops plunging at around 60....

Thanks,

Levi

[GoFaster]

I had a similar issue.  Just finished a DIY gantry router.  Downloaded Quantum to see if I could reduce the jerks.  It does and very well.  But on a 2.5D contouring test file, the Z-axis made some really bad noises and seemed to either lose or ignore steps when raising.  I killed the job when I saw the bit eating the spoilboard.
This was with 100ipm feeds on XY and 60 on Z.  Max vel is 200ipm on XY and 160 on Z, accel is 15 XY and 20 Z.
Dropped the job feed rate to 50 on XY and 30 on Z and it still happened.  I disable hermite curving and it was smooth as silk.
Just a FYI.

- Felix

[joechevy2000]

are their any updates for this, i could not get the slave axis to work.