Has anyone installed a VFD on a Precision Matthews knee mill or plan to in the future?

[Pcmaker]

I have a PM-835S which has a step pulley system and even before I made the purchase, I knew I'd be upgrading to a VFD system in the future.

I think all PM knee mills have similar heads, depending on if it has a variable speed or step pulley system.

I asked PM awhile back, and they said they'll have 3 phase motors available for purchase sometime February or March of next year for around $400

Is anyone here thinking of doing the transition?

 

[davidcarmichael]

I have a PM-835S which has a step pulley system and even before I made the purchase, I knew I'd be upgrading to a VFD system in the future.

I think all PM knee mills have similar heads, depending on if it has a variable speed or step pulley system.

I asked PM awhile back, and they said they'll have 3 phase motors available for purchase sometime February or March of next year for around $400

Is anyone here thinking of doing the transition?

Already done it on a PM-835S over a year ago. A vast improvement.

 

[davidpbest]

Yes. Control system by Mark Jacobs:

 

[Pcmaker]

Wow you went overboard

All I want is speed control, reverse capability and an RPM meter

 

[Steve R]

I have PM949TS and installed the VFD on mine. I use the control OPE-SRmini to control the speed. It plugs into the VFD by a lan-cable. I haven't planed on using coolant so I mounted the VFD inside the mill. Since it came with 3ph motor all I had to do was attach the wires to the vfd and used the factory switch to turn on/off and for the direction. If I do switch to using coolant I just have to take it out and mount outside. Put a disconnect switch on the outside to turn everything on/off. Put a 4 outlet box on the back for power drives. I have a halo led light I plan on mounting around the spindle. 3D printing a mount for the halo light now, should be done in about 4 more hours. I have not got a tach installed yet, have not figured out a good way to mount the sensor for a tach. I have a tach on hand but as of now the only way I can see to do this is to make a ring to fit on the spindle and to hold the magnet. If you extend the quill down you would loose the tach signal. Was thinking about taking the head apart and seeing about being able to mount the sensor up there below the back gear setup.

 

[wrmiller]

I mounted the VFD on my 935 on the inside of the access panel on the side of the column. It's been 5 or 6 years, so maybe I should remove the panel and see if everything is ok. It's worked great all these years.

 

[7milesup]

Just noticed Dave's circuit breakers. The Eaton ones in the control box. I had well over a 100 of them. Tried selling them on eBay with no takers. Just threw them all out.

 

[Pcmaker]

How did you guys figure out the rpm display?

 

[wrmiller]

I put a small piece of reflective tape on the spindle and aim one of those cheap hand-held rpm thingies at it when I want to know the rpm of the spindle. Worked pretty well, for the time or two I used it.

 

[Pcmaker]

Using a step pulley is such a hassle especially with a mill this tall. I hope PM has those 3 phase motors coming in soon.