Hi everyone,I’m adding a C axis to my CNC lathe and running into an issue I can’t figure out.Previously, the axis would rotate (basic motion was working), but I hadn’t properly tuned the scale or step settings yet. Now, after adjusting parameters, I’m getting a consistent problem:As soon as I enable the machine and try to jog the C axis (C+ or C-), LinuxCNC immediately throws a
“Joint 2 error”and disables the machine.Details:
- AC servo drive in step/dir mode
- Encoder is connected only to the drive (not to LinuxCNC)
- C axis is configured as ANGULAR
- SCALE = 27.78 (assuming 10,000 pulses per revolution)
- MAX_VELOCITY ≈ 60–72 deg/sec
- MAX_ACCELERATION ≈ 200–230 deg/sec²
The axis previously rotated before I changed scaling parameters, so I don’t believe it’s a wiring issue.I’m trying to understand:
- Why LinuxCNC is throwing a Joint 2 error immediately
- Whether this is a scaling issue, limits issue, or configuration issue
- What I should check next (HAL wiring, limits, FERROR, kinematics, etc.)
Any guidance from someone experienced with adding a C axis to a lathe would be greatly appreciated.
Also I did use ChatGPT to turn my ape thoughts into human ones, anyways any help would be appreciated thanks!!!
