Centroid Community CNC Support Forum

The vfd in my control cabinet went out with a load pop and a few sparks. I have a new one but can’t get the spindle to run thru cnc12. When I started checking voltages coming out of the acorn, I don’t get a reading from the oc4 or any of the other terminals on that block. Is it possible that when the vfd failed that it could have damaged the acorn controller also? I can run the spindle manually so I know it’s good.
Thanks in advance for any and all help

I'm not sure what you mean by oc4 and "the other terminals on that block" but the analog voltage comes out of the Acorn on the H8 terminals. There's only two terminals.

To test the Acorn you should run the "spindle bench test" procedure outline in the install manual in section 4.2. This will tell you whether or not the analog output on Acorn is working properly or not.

If it passes this test then you have a wiring or programming issue with the VFD.

The oc4 controls the spin fwd. I’ll try the bench test. Thanks

If oc4 = Output 4, it is only a relay, there is no voltage from Acorn, but it can switch external supplied voltage.

Uwe

All the relay does is touch two wires together.

Get the vfd running and programmed without acorn attached. You should be able to use a 9v battery to simulate the 0-10v and touch two wires together for spin fwd. You don't just plug in a vfd. They have to have parameters set for how you want them to activate and operate. You also set your spindle motor parameters as far as max speed, max amps. ect....

eldunn wrote: ↑Tue Jul 15, 2025 11:05 pm The oc4 controls the spin fwd. I’ll try the bench test. Thanks

One of the Acorns relay outputs (1-8) is programmed to activate "spinFWD", hence my confusion to anything called oc4. Did you mean OUT4?

Post a current report so we can see how you have the Acorn configured and a link to your VFD manual if you need help wiring or programming it. We'd need a lot more info to be able to help you more. As Ken mentioned, there are parameters in the VFD that have to be changed for Acorn to control it.

https://m.media-amazon.com/images/I/B111BT+2GvL.pdf I believe this is the correct manual

ShawnM wrote: ↑Wed Jul 16, 2025 8:42 am

eldunn wrote: ↑Tue Jul 15, 2025 11:05 pm The oc4 controls the spin fwd. I’ll try the bench test. Thanks

One of the Acorns relay outputs (1-8) is programmed to activate "spinFWD", hence my confusion to anything called oc4. Did you mean OUT4?

Post a current report so we can see how you have the Acorn configured and a link to your VFD manual if you need help wiring or programming it. We'd need a lot more info to be able to help you more. As Ken mentioned, there are parameters in the VFD that have to be changed for Acorn to control it.

Yes I did mean out4

When I hit cycle/start the x,y and z axes move according the the file that's loaded. The spindle still doesn't start. While working on it last night, I noticed that I get a code of 5038-specified spin speed< min speed. Could that be the issue? My max rpm is 18k at 300Hz. My project file calls for 15k rpm. The frequency reference lower limit in the vfd is set at 50Hz. So I dont think the specified speed is < min speed. I may be grasping at this point.
Any thoughts/help is much appreciated.

Your report from yesterday says that the minimum spindle speed set in CNC12 is 15k RPM. Is that truly the minimum speed of the spindle?