Common fixes for near near, broken bench grinder

[bofe954]

Common fixes for near new, broken bench grinder

Bought a new Jet JB6A bench grinder. It is out of warranty and it might have 1 hour of actual use on it.

Now when I turn it on it just hums. I can spin the wheels by hand when it is off, they spin freely.

Any really common things that can go on a basically brand new bench grinder?

 

[Davefr]

Bought a new Jet JB6A bench grinder. It is out of warranty and it might have 1 hour of actual use on it.

Now when I turn it on it just hums. I can spin the wheels by hand when it is off, they spin freely.

Any really common things that can go on a basically brand new bench grinder?

Turn it on and give it a spin by hand. Will it then come up to speed?

If so, the problem is likely the starting circuit. The starting circuit generally involves a capacitor or start relay and these would be the most common components to fail. It could also be a dirty or damaged centrifical switch if this model has one. The least likely would be the actual start windings. It could also be something as simple as a loose connector in the base.

Don't leave it on for more then a few seconds if it doesn't start. That can overheat and damage the windings.

You need to do some research and get the schematic or wiring diagram for this model grinder and then just start narrowing down the problem.

 

[Fretters]

Like Dave says, just give the wheel a quick flick by hand when you turn it on and see if it runs fine from there, which it likely will. Capacitor, or wiring of, is the general cause.

 

[frankush]

Be real careful giving it that initial spin. If it starts, it could get nasty if you're not.

 

[CNGsaves]

OP . . . gotta ask . .
. . . . .
. . . . . . . . What is a . . . . . "near, near " . . . . bench grinder ??

PICS ??

 

[dutchgray]

Get it spinning first by hand and then hit the power, less risk of grinding your fingers.

 

[bofe954]

meant "near new" not "near near", I edited, thanks

 

[CNGsaves]

meant "near new" not "near near", I edited, thanks

That's what I was guessing.

Didn't find much on JBG-6A with quick Google research. Based on info I did find on JBG-8A then I'd assume you have 6 inch Jet grinder ??

Is yours also 1 HP like the 8" Jet that I found below at Northern Tool ?? That 8" looks like very nice grinder. Here's YouTube on the 8" model:

OP, your grinder is keeper so hope you find the problem. Update your GJ Profile with location as GJer may be able to suggest a local motor repair shop near you, or call Northern Tool and see if they can provide help. Good luck.

 

[bofe954]

Yeah it's the 6 inch version of what you saw. They do have it at Northern. Just annoying because I felt like I went out of my way to actually buy something decent.
It does get going if I get it spinning. Can't spin and then start, have to start it and spin it a few times.

I am going to search for grinder rebuilds and try and fix it myself. I'll look at the wiring and maybe replace the capacitor.

 

[G_P]

It is more than likely a bad start capacitor.

 

[drivesitfar]

once you do get it right again Jet grinders are usually a good brand and work well.

did you buy it from a Craigslist person or an estate or garage sale?

 

[bofe954]

I bought it brand new. Just don't really use it much. The warranty is 2 years and I am trying to track down when I bought it to see if I am in that window, but I don't think I am. It looks brand new, and I don't think it has an hour of actual use on it.