VFD for 120v bench grinder

[mike johnston]

I have a 1hp jet bench grinder (3450 rpm’s). Is there such a thing as a VFD to slow it down? If so recommendations. I’ve looked online, just would like a little knowledge before I call and order something. Or get talked into something.

thank you

[Dan Friedrichs]

The issue will be that your existing single-phase motor likely has a centrifugal switch which depends on motor speed.

You definitely could do it with a 3-phase motor.

[Bill Dufour]

Only if it is a shaded pole motor with no centrifugal switch, unlikely. If it is save money and just use a scr control.
Bill D

[ray grundhoefer]

You cannot use a vfd on a single phase motor. 3 phase only

[Richard Coers]

You cannot use a vfd on a single phase motor. 3 phase only
False. You can buy VFDs with single phase in and out. https://www.amazon.com/Single-Output-Variable-Frequency-Control/dp/B0897B6CRR/ref=sr_1_5?crid=INKYK4W19A47&keywords=vfd%2Bsingle%2Bphase%2Bto%2Bsingle%2Bphas e%2B110v%2B1hp&qid=1702525246&sprefix=vfd%2Bsin%2Caps%2C94&sr=8-5&ufe=app_do%3Aamzn1.fos.17d9e15d-4e43-4581-b373-0e5c1a776d5d&th=1

[roger wiegand]

It's probably cheaper and easier to buy a low or variable speed grinder. Your existing motor may well not be inverter rated even if it is the right kind of motor (I'm not wise in these things). Or put a smaller diameter grinding wheel on it to achieve lower ft/sec at the same rotational speed.

[Curt Harms]

It's probably cheaper and easier to buy a low or variable speed grinder. Your existing motor may well not be inverter rated even if it is the right kind of motor (I'm not wise in these things). Or put a smaller diameter grinding wheel on it to achieve lower ft/sec at the same rotational speed.

That seems like it would be easiest and cheapest if you can find stones with suitable bores. Would rests and jigs fit?

[Bill Howatt]

Likely little financial advantage, if any, going the single-phase VFD route and a good chance of burning up the motor since they weren't designed for this type of service. Big difference fooling with VFDs compared to just having to plug the power cord into the wall!

[George Yetka]

Look for a 120v rheostat. Match the amp draw of your grinder. Luckily these are far cheaper then VFDs

[John Lanciani]

Look for a 120v rheostat. Match the amp draw of your grinder. Luckily these are far cheaper then VFDs

That's a good way to burn up the grinder and the rheostat. Induction motors don't take kindly to low voltage.

[Jim Becker]

Look for a 120v rheostat. Match the amp draw of your grinder. Luckily these are far cheaper then VFDs
This cannot be used with induction motors. Only "universal" (screamer) type motors.

[George Yetka]

This cannot be used with induction motors. Only "universal" (screamer) type motors.

Are bench grinders ususally induction? Mine is a variable speed with a built in rheostat

[Bill Dufour]

I put an SCR speed control on my whole house fan. Works fine. Of course this is a no starting load shaded pole motor. It would not work if it was a capacitor motor.
I suppose a VFD would run a single phase motor as long as rpm was above switching speed or higher. Most want to slow down a grinder not speed it up
Bill D

[Jim Becker]

Are bench grinders ususally induction? Mine is a variable speed with a built in rheostat
Most are indeed induction motors...variable speed isn't a common thing you'll find on most grinders.

[mike johnston]

Thank you all. Think I will use it the way it is. I bought it to reshape some scrapers. Although I thought it was los speed to begin with. I will be extra careful, and tread lightly

[ray grundhoefer]

False. You can buy VFDs with single phase in and out. https://www.amazon.com/Single-Output-Variable-Frequency-Control/dp/B0897B6CRR/ref=sr_1_5?crid=INKYK4W19A47&keywords=vfd%2Bsingle%2Bphase%2Bto%2Bsingle%2Bphas e%2B110v%2B1hp&qid=1702525246&sprefix=vfd%2Bsin%2Caps%2C94&sr=8-5&ufe=app_do%3Aamzn1.fos.17d9e15d-4e43-4581-b373-0e5c1a776d5d&th=1
You are right you can apparently. However only on certain motors and it does not work very well

[Dave Sabo]

Why don’t ya just get this :

https://www.harborfreight.com/power-tools/grinders/bench-grinders/8-in-variable-speed-bench-grinder-with-led-work-light-59300.html