Baldor Grinder 712 long time to stop

[Beaupr]

I picked up a Baldor 712 (1/2 hp 7" wheel) grinder today. Seems to run smooth, bearings aren't noisy.

My question is, do Baldor grinders normally take a very long time to wind down and come to a stop?

Mine took 2 mins and 35 seconds. That seems very long to me. Maybe it's a good sign, that the bearings are in good shape? Maybe a bad sign if there's something not working that's designed to stop/slow the motor.

Interested in your replies.

Thanks
Rob

 

[The Cobbler]

it's a good thing. that's what happens with precision stuff.

 

[kaymccampbell]

I wish my **** bench grinder took over two minutes to wind down. The longer it takes, better the machine.

 

[torqueman2002]

Fresh new well greased bearings will tend to slow down sooner, all other thing being equal, than older dry bearings.

I have rebuilt dozens of Craftsman 'Block' grinders and a few Baldor grinders; 2+ minuets is excessive.

I just timed the spin down on a 0.50 & 0.33 HP Model 7312B Baldor. It is about 17 seconds. There is no brake on this model.
(PM me for a link to it's restore.)




You have a top of the line grinder and replacing the bearings is straight forward. When doing that, I usually replace the other consumables:

• power cord
• capacitor, if fitted
• stones and wire wheels

 

[American Locomotive]

2.5 minutes sounds about right for a grinder with 7" wheels. A new grinder with freshly packed bearings will slow down a bit faster.

If a bench grinder came to a stop in 17 seconds with two stone wheels, I would assume something was wrong with it. That's way too fast. About normal if it has a wire wheel, though.

 

[torqueman2002]

I did some more timed spin-down measurements.

For my all original ~20 year old Dayton 1/3HP Model 4Z672D grinder with two 6" stones - 2 mins. 10 seconds.

For my restored (May 2011) CM 'Block' 3/4-HP grinder, Model 397.19350, with 7" wire wheels - 15.60 seconds.

The Baldor above (rebuild ~April 2020) has 1 wire wheel, and 1 stone. It has the lowest number of operational hours, and can run at 1/2-HP or 1/3-HP | 3,600 RPM or 1,800 RPM.

The Dayton has the highest number of operational hours,

The CM 'Block' grinder has somewhere between the two.

 

[Davefr]

I believe Baldors have a run capacitor that's always in circuit. Since there's no centrifical switch causing friction, they coast for a long time after being turned off.

 

[Beaupr]

I haven't decided if I'm going to replace the bearings just yet. They don't make any noise (that I can tell) and starting and stopping seems smooth. If it ain't broke, don't fix it.

2.5 minutes sounds about right for a grinder with 7" wheels.

It does have 2 stone wheels so thank you (and others) for confirming 2+ mins is not uncommon.

Since there's no centrifical switch causing friction, they coast for a long time after being turned off.

Thanks for confirming this. I wasn't sure if something internally wasn't working properly.

 

[finn]

I haven't decided if I'm going to replace the bearings just yet. They don't make any noise (that I can tell) and starting and stopping seems smooth. If it ain't broke, don't fix it.



It does have 2 stone wheels so thank you (and others) for confirming 2+ mins is not uncommon.



Thanks for confirming this. I wasn't sure if something internally wasn't working properly.

Bad bearings would lead to short spin down times, not long times.

 

[Steve_P]

I have a small scar on my knee from a stand mounted grinder that was still spinning forever after I turned it off. At that time it was a newer HF - that I still have This was 30+ years ago so I don't remember the details other than I used the grinder, and then needed to climb a ladder next to it for some reason. And then oops.... Maybe I was shortening something that I was screwing into the ceiling.

 

[micromind]

Having a wire wheel on it will make it slow down quicker than having grinding wheels.

Having 2 fairly new thick grinding wheels will make it take a long time to stop.

 

[cvairwerks]

I’ve seen Queen City grinders take close to 10 minutes to spool down. Granted, they were 12 inch wheels.

 

[1982fxr]

I've been on here a long time. Until about a year ago everyone touted long run downs as good.

Then guys started saying it was a bearing problem that needed to be addressed.