Belt Grinder Variable Speed Upgrade

When I built my belt grinder i used a 2 hp single phase motor I had on hand. I wasn’t exactly sure how much I’d use the grinder, and I wasn’t sure how necessary variable speed would be. I since discovered it is one of the most used pieces of equipment in my shop, and almost invaluable for making knives. I also found myself wishing I could slow the belt down quit often.

So I decided to upgrade. I purchased these two items.

IronHorse premium efficiency AC induction motor, general purpose and inverter duty, 2hp, 3-phase, 208-230/460 VAC, 3600rpm, TEFC, 56C/HC frame, rolled steel, rigid base/C-face mount

KB Electronics, 9520, KBAC-27D (Gray), 1.5;2HP, 1-Phase, 110-120V;200-240V (Input), Nema 4X Enclosure, Variable Frequency Drives

Unfortunately for me, I did’t order the VFD from Amazon. It came and I hooked it up and it didn’t work. The status light was doing a slow red blink. A search on the internet suggested a bad unit. I called KB and sure enough, they said the unit was shorted. I could return it to them, they would assess it, and fix it or send a new one. I was not a happy camper and did not want to wait that long.

I called State Motor and Control Solutions where i had ordered it online and they immediately sent out a new VFD, but I had to pay the $30 return shipping on the bad one (I would have had to pay this anyway). Not ideal, and not perfect customer service, but better than the manufacturer. I should have ordered from Amazon I guess.

My motor came wired for 220.

I’m not sure what the U,V, and W stand for but they get connected to the 3 lines on the motor. When i connected mine, the motor was running backwards for my grinder. Another quick search and I discovered changing two wires on the motor changes direction. It worked like a charm.

Switching two lines coming into the motor got it running in the correct direction.

Being able to control the belt is a big help, especially grinding bevels. It’s also helpful for sanding wood that’s prone to burn. I’m finding the variable speed a huge help and use it almost every time i use the grinder now. It’s well worth the extra effort if you’re thinking of building a grinder.



As an Amazon associate, we earn income from qualifying purchases when you click on a link. Your link clicks help us fund our website.



Leave a Reply