Centroid Community CNC Support Forum

Looking for some guidance on selecting a VFD for my spindle motor and pairing it with the Acorn and CNC12 software.

The spindle motor I am going to be using is a Suhner BEX35. I will attach a picture of the motor nameplate below.

I am looking at the specs on the nameplate for 230V at 60 Hz since I have access to this. The spindle is being used on a gantry mill and will primarily be running at low rpm, 0-400 and using endmills to mill keyways into shafts.

Does the input of the VFD matter when it comes down to single or three phase? Or does it just matter that the output is three phase?

From a little research I was looking at a VFD with an output of 10A or more and 4 HP or more. Essentially double the motor specs.

This is all new to me so any help would be greatly appreciated.

You do not need to double the power rating, modern VFDs are designed to run the load they advertise (so long as they are not cheapest chinesium you can find).

Yes input phase matters, if you are running it on single phase, you need to make sure the VFD is rated for single phase input and three phase output. Some VFDs are rated for single or three phase input, that would also work.

Something like this would probably be fine, Centroid has schematics for this drive as well, which should make life a little easier;

https://www.automationdirect.com/adc/sh ... /gs21-22p0

Or this if you want to be very conservative.

https://www.automationdirect.com/adc/sh ... /gs21-23p0

Thank you for your help Wes. Another newbie question, but right now during the building and testing stages of the machine, I have the meanwell power supply that came with the Acorn connected to a standard 110/120 V outlet. If the spindle motor requires 230VAC, do I switch the power incoming to the meanwell to 230V?

You can keep two power feeds to the machine if you wish. If you have other 120V accessories, this is probably easiest. You can also run a 4-wire 230V service (split-phase 230V with a neutral). That way you would end up with 230V service as well as two 120V services. Just be sure to keep the 120V loads balanced between the two services.

If you don't have any other 120V loads, just run a 3-wire 230V service and run the Meanwell supply off that. The Meanwell supply is multi-voltage rated.

NickB wrote: ↑Thu Jan 04, 2024 10:51 am Thank you for your help Wes. Another newbie question, but right now during the building and testing stages of the machine, I have the meanwell power supply that came with the Acorn connected to a standard 110/120 V outlet. If the spindle motor requires 230VAC, do I switch the power incoming to the meanwell to 230V?

Yeah, like tblough said you can run that meanwell PS on 120 or 240. Depends on the 240v circuit you have run for your machine. Some of them are only 3 wire (2 hots and a ground) and some are 4 that have the neutral as well as the other wires. If all of your electronics and accessories (pumps etc) run on 240, its probably simpler to keep the whole cabinet 240.