VFD not listening to G-code

[ben2ek (Brian)]

Edit: It started working again this morning, but last night it wouldn’t work at all.
Edit 2: Nope, stopped mid-cut again. VFD refuses to re-start the spindle after pushing the e-brake.

My VFD stopped spinning mid-cut and I’m lucky I saw it stop before it plunged again. No idea what happened that would have caused this problem.

I double checked the VFD and sent the MDI code:

• M3S18000 reads 275.5 RPM
• M3S20000 reads 305.0 RPM
• M3S24000 reads 396.0 RPM

M5 sends it back to 0, as it should. Needless to say the VFD doesn’t spin at all at these low of RPMS.

My VFD runs at about -10% of the G-code RPM, which I’m told is normal. But this makes me very very worried for future cuts.

What is happening to the VFD?

The G-code in my file reads M03S20000 - and it has the same RPM.

[AndyP (Andy)]

I started to respond but had to check.

My VFD show 305.3Hz for 18000 RPM. So yours appears low at 18000.

I have an Invertek Drive VFD and a chinese no name aircooled spindle.

[jtclose (Jim Close)]

I had an issue where the VFD would not spin on start up after changing a tool bit.
The issue was wood dust had gotten into the spindle. I had not run the vacuum for a run.

So now I confirm the spindle rotates freely before starting a job.
I remember to knock the dust out of the collet at the same time.

I have not had it stop in mid cut.