Fiber/Composite/Nylon wheel warnings

[Machinehead]

I was going to buy a fiber wheel for a bench grinder and noticed it says on most its recommended for 1800-2800 rpm max 3000rpm right on the wheel. This is on Amazon. And that's for a 6" or 8" wheel. But sellers/manufacturers will also say in the notes max is 3500rpm???
Everybody Ive seen on Youtube and on the sellers websites are using Harbor Freight , Wen, Jen etc. which most run 3400-3600. Ive seen a few warn about it and were using HF units. Nobody I saw used a variable speed type.
Is this even a problem? If it broke apart would nylon hurt or just wear a face shield?

 

[Beerhippie]

Grinders generally come in low-and high-speed versions, with the low speed being around 1750 RPM. That's what those wheels are made for.

And, yes, any kind of wheel coming apart at 3,500+ RPM can cause serious bodily harm or death.

Hmm...let's see, 8 inches times pi times 3,500 rpm equal 87,965 inches per minute or 122 feet per second--unless I screwed that up badly. So archery/slingshot speeds, but still damned dangerous.

 

[PCustoms]

I bought a fiber cup brush last spring and used it on my variable speed polisher.

Plenty of destructive power at ~2400rpm

 

[natas2000]

Aww man I wanted to get on too, I should of never read this.

 

[nadogail]

Spinning Grinding Wheels are "Accidents Waiting to Happen". Stand to the side and allow them to run at speed before getting in line with their axis. inspect them frequently and watch to make sure someone did not load them up with Aluminum or other inappropriate metal.

Watch out for the possibility of their being struck by anything that might Crack them.

Never over speed a grinding wheel.

 

[Machinehead]

Well dang, i'd be under the max they say at 3450rpm but not by much.
Why do they say max is 3500 or 4000 on one brand but it then kind of says no that's still too much.

 

[Beerhippie]

Well dang, i'd be under the max they say at 3450rpm but not by much.
Why do they say max is 3500 or 4000 on one brand but it then kind of says no that's still too much.

I'd use the most conservative speed listed and forget the rest.

 

[L.Cheapo]

When I was a young man working in a shop I had a cutoff wheel break apart on a die grinder. A piece about the size of a dime embedded itself in my cheek.

It was a shop tool. It appeared someone dropped the tool and cracked the wheel before I picked it up and used it.

From that day on I only use my own disks/wheels, and only buy high quality name brand consumables appropriately rated for the tool.

And even then, I wear a face shield and eye protection.

 

[Machinehead]

I'll probably buy a 1x30 sander and use conditioning belt because they seem to get the same affect.
But I'm baffled by the markings like the rpm are in metric Then people who seem established use them and warn you while running it on a high rpm unit? Oh well.

 

[PCustoms]

But I'm baffled by the markings like the rpm are in metric

How is rpm listed in metric?

 

[Oregon Dave]

I was going to buy a fiber wheel for a bench grinder and noticed it says on most its recommended for 1800-2800 rpm max 3000rpm right on the wheel. This is on Amazon. And that's for a 6" or 8" wheel. But sellers/manufacturers will also say in the notes max is 3500rpm???
Everybody Ive seen on Youtube and on the sellers websites are using Harbor Freight , Wen, Jen etc. which most run 3400-3600. Ive seen a few warn about it and were using HF units. Nobody I saw used a variable speed type.
Is this even a problem? If it broke apart would nylon hurt or just wear a face shield?

As others have wisely advised; be conservative, wear proper safety gear and lose the stupid cells before operating power equipment.

Another 'watch-out for'; is under some conditions heat is generated, plastic melts, liquid plastic sticks, grabs; things launch - sometimes in very very short order. If a Machinehead you already know to go slow and easy with a new and unfamiliar product.