[Lithgowguy]

Hi, New member looking for help and advice. I have a custom built CNC which is no longer supported. It has been going well for years, until the spindle just started to spin up on it's own, maybe doing 30RPM. To rule out unwanted command prompts, I disconnected the CAT 6 cable and found that the spindle is still rotating slowly after machine start up. It's as though it is picking up a residual current from somewhere. I have examined all the wiring to ensure that there are no shorts across wiring. After extensive testing today, the spindle now will not run on the S18000 M3 command in the G code. Given that the spindle was acting independently and now not at all, I suspect a problem with the invertor (Fuling DZB300B002.2L2A) but welcome any advice

[michaelgatling]

Hi, New member looking for help and advice. I have a custom built CNC which is no longer supported. It has been going well for years, until the spindle just started to spin up on it's own, maybe doing 30RPM. To rule out unwanted command prompts, I disconnected the CAT 6 cable and found that the spindle is still rotating slowly after machine start up. It's as though it is picking up a residual current from somewhere. I have examined all the wiring to ensure that there are no shorts across wiring. After extensive testing today, the spindle now will not run on the S18000 M3 command in the G code. Given that the spindle was acting independently and now not at all, I suspect a problem with the invertor (Fuling DZB300B002.2L2A) but welcome any advice brawl stars online

Hello, sometimes, inverters can enter a fault state. Try resetting the inverter to its factory settings. Ensure that the inverter settings (like frequency and speed settings) are correctly configured for your spindle.

[costumespherical]

Hi, New member looking for help and advice. I have a custom built CNC which is no longer supported. It has been going well for years, until the spindle just started to spin up on it's own, maybe doing 30RPM. To rule out unwanted command prompts Survival Race, I disconnected the CAT 6 cable and found that the spindle is still rotating slowly after machine start up. It's as though it is picking up a residual current from somewhere. I have examined all the wiring to ensure that there are no shorts across wiring. After extensive testing today, the spindle now will not run on the S18000 M3 command in the G code. Given that the spindle was acting independently and now not at all, I suspect a problem with the invertor (Fuling DZB300B002.2L2A) but welcome any advice

You need to confirm that the drive is still set to accept external commands (check settings like `P0.01`, `P0.03`, etc., depending on the model). Check the analog input wiring (usually 0–10V for speed and digital for run commands). If the analog input circuit is broken or misconfigured, the VFD will not respond to the speed setpoint. If the drive has a manual keypad mode, try running the spindle directly from the VFD control panel. If that works, that confirms the spindle and VFD output stage are fine and the problem lies with the control circuit or G-code interface.