Speed control for a 220v 1PH 3HP AC motor?

[mksj]

This may also be a reasonable option if you have a 28 mm shaft which is the standard size for a 100L motor. You can remove the variable pulley attached, motor should be good for at least 2X its base speed. There are also other metric 100L motors that in various configurations that I have also seen used with an adapter plate, but issue may be the shaft is too short.

Spindle Motor with Pulley Assembly for Mill- MP8008 | eBay

Part #: MP8008. 230V/3 phase 3 HP Motor. Can fit Acer, Bridgeport, and most Taiwanese Variable Speed Milling Head. Speed: 1,430/1,720 RPM. Orders under 150 lbs. Orders above 150 lbs. Piscataway Office.

www.ebay.com

 

[Ken226]

Assuming the 835s has the same motor that came off my 935, it was a 28mm shaft, but had a shoulder and step down to 22mm on the end, where the pulley fits into the motor shaft.

I set my pulley up in my lathes 4 jaw and bored it from 22 to 28mm, then used a piece of ground HSS in my mills spindle, kinda like a vertical shaper, to broach a new keyway.

The stock setup used a screw/washer threaded into the end of the shaft to secure the pulley. The new Helmke motor wouldn't accommodate the same method, so I drilled and tapped the pulley for a setscrew, to bear against the key.

 

[Pcmaker]

I'll just wait for PM to have it in stock. The other options cost twice as much and need considerable modifications in order to fit.

 

[hman]

I had a 3 phase motor on hand when I bought my 835S, so I designed and built a mount out of aluminum. Here's a write-up, in case you decide to go that route:

Converting a knee mill to 3phase/VFD

I've recently bought a Precision Matthews PM-835S. Advertised as a "small" knee mill, it's still amazingly massive - and TALL. I've had to build a platform to stand on (re-using some of the the 2x4s and OSB the mill was crated with), just to be able to reach some of the controls and levers...

www.hobby-machinist.com