5/8 11 threaded grinding disc spinning off.

[PoorOwner]

hi I could use a little advise
Looking at this picture the grinding wheel spins on clockwise to the arbor

But the tool rotate counter clockwise when looking at this photo. So the wheel spins off sooner or later.


What am I doing wrong?

It comes with an arbor parts too but the wheel I can find have the nut on it already

 

[PoorOwner]

Here is the wheel flipped over.

It leaves no space for a locking collar.

It's a 7" grinder.

 

[dontlifttoshift]

It only spins off when the grinder is away from the work piece and you let off the trigger, right?

 

[PoorOwner]

I am not sure what happened. Just came off and walked across the pavement
Of course it was new and I was spinning it up and down a bit.
Maybe I just didn't tighten it enough then?

 

[INSP380]

You're missing the center lock screw. Is the center of the 5/8-11 shaft threaded? If so, a pan head screw goes in ther to lock the disc on. We have these on all of our IR grinders, and it's against safety policy to run without them.

Steve.

 

[zkling]

Not tight enough probably. I've had a few that would do that and they were missing a O ring type that cushioned the wheel nut to the spindle shoulder.

 

[PoorOwner]

Yes it is threaded. For a small machine screw type. The clamp arbor setup has it. But I don't see this in the parts diagram so what are my options? Would the head of this screw have a fairly big flange
The dewalt nut is hard to get to with an adjustable wrench and looks to need a 1" wrench which I don't have with me all the time!
thin access type would even be better

 

[INSP380]

Yes, large enough to lock the 5/8-11 thread.

Steve

 

[INSP380]

I can take a picture tomorrow..

Steve

 

[PoorOwner]

Darn. The grinder is awesome but not sure what to do except maybe find a bolt and washer that fits to lock.

I have hard time finding the 7" disc that clamp on without the nut built in too

I bought a flap disc with 7/8 hole but the clamp bottoms out before clamping the disc tight. So I need to find a washer to space it too.

 

[zkling]

Why did you go pneumatic over electric? Pneumatic grinders are air hogs.

 

[PoorOwner]

Got a pretty good deal..

Did not drain the 80 gallon that quickly. I set the pressure at 110 and when I pulled trigger it only dropped to 90 when running.

Which is a higher consumption tool but not too bad. It grinds things down quickly.

 

[INSP380]

A bolt and washer will do the trick. Not sure what RPM you run, ours turn at 7500. Scary when they come off.

Steve

 

[PoorOwner]

Thanks. I have some thread locker (vc3) that creates a nylon nut effect I think that might make it much safer since the disc cannot walk off the 5/8 thread in any sudden manner. Even without the little hex bolt for the center.

I was just a couple inches from the ground (didn't drop it) and the wheel came off skipped around spinning until it hit a curb.
Would I need to throw the disc away now in risk of shattering wasn't sure about safety protocol for things like that. I know dropped bench grinder wheel is not good to be installed again.

The grinder spins a 7800 rpm and the wheel rated 7900 or something like that

 

[metaleltr]

If it hit a curb I would trash it. The rotating mass of the disk likely was enough to overcome the torque you installed the wheel with when you let off the trigger. Locking the wheel down tighter should fix it without installing a lock bolt. If the grinder has an arbor lock use it and a wrench to torque the wheel down