14" pedestal grinder

Ignoramus

This is a big grinder as things so. But I can't figure out how the wheel size relates to the power. Or possibly how wheel size changes power. Of course size cvan be a factor in safety but a friend in a blacksmith shop has three grinders ove 10 HP and has no problems. He knows how to handle things like this.

Do you have the proper power for this? Probably 3 phase 220 or more.

Bob AZ

Maybe a wider wheel can remove more material per minute.

OK, so, how do they use these grinders? Why do they need to much power? Maybe I can learn something.

Not a problem AT ALL.

If you buy it..I have brand new wheels Ill give you simply for the shipping

Gunner

"IMHO, some people here give Jeff far more attention than he deserves, but obviously craves. The most appropriate response, and perhaps the cruelest, IMO, is to simply killfile and ignore him. An alternative, if you must, would be to post the same standard reply to his every post, listing the manifold reasons why he ought to be ignored. Just my $0.02 worth."

I've never seen a bench mounted grinder that size , but have used a few that have been made as floor mounted models . The 14" wheels rotate slower that say an 8 ' bench model . They are used for rough fettling of castings and large pieces of steel etc, they will take a fair bit of pressure and will remove large amounts of material quickly..

I've never seen a bench mounted grinder that size , but have used a few that have been made as floor mounted models . The 14" wheels rotate slower that say an 8" bench model . They are used for rough fettling of castings and large pieces of steel etc, they will take a fair bit of pressure and will remove large amounts of material quickly..

They are no more dangerous than any other grinder of the type ,ceratainly less dangerous that a hand held angle grinder. If I had 3 phase power in my workshop I would certainly have one.

As far as the size-related hazards, don't take the guards off. Even small stones can kill when they fail - big ones are better at it. And watch that loose clothing - you might stall a 1 hp grinder and get your hand dragged into a 5hp unit from the same sleeve snag.

You can obviously spin any size stone up with as small a motor as you like, if you don't manage to fry the motor while bringing the stone up to speed from inertia - but the point of a grinder is to remove material, and being able to shove material into the stone and have it ground away is what they are for - not needing a long-ramp VFD to start the thing is a side benefit of using a "large enough" motor. That said, plenty of home shops would likely be fine with 1-1.5 hp driving (but that's hard to do on a grinder of that design, rather than one with a belt drive where swapping the motor is easy) since one rarely reefs on the equipment as hard as in a production shop. You'd still get the benefit of a larger radius on the grind, and the downside of how much the stones cost, but the upside of how far you can grind them down without being too small.

Of course, less inertia, less hazard from failure and less media cost (for home-type use) with large (or no) radius can be had with a belt sander, where you can use the contact wheel the same as a grinder, or the flat platen. Cue horrified gasps, since there are slight differences between grinding on a belt sander and grinding on a stone, but with a properly tensioned belt sander they are pretty minor. I'll let someone else dissect them at length.

This is awesome. If I win it, I will take you up on your offer. I can prepay a label, it will be cheaper for me.

Thanks Gunner.

So... Have you seen people use those beasts? How are they used?

Power is directly related to the moment of inertia, the bigger that is for the object being spun, the more power required. Generally, you're going on the basis of surface feet per minute, so you don't have to spin a large wheel as fast as a small one to get the same sfm. Power required goes up as the square of the rpm, if the wheel moment of inertia stays the same. Just some of the variables to play with.

Stan

Besides "carefully"?

You simply use them like any other grinder. They dont spin all that fast ..but because of the size of the wheel..it keeps up the SFM.

Shrug...they work good, and its really really really hard to stall one.

As someone said..dont get your sleeve snagged in one. Other than that..use em like you would a regular grinder.

Gunner

"IMHO, some people here give Jeff far more attention than he deserves, but obviously craves. The most appropriate response, and perhaps the cruelest, IMO, is to simply killfile and ignore him. An alternative, if you must, would be to post the same standard reply to his every post, listing the manifold reasons why he ought to be ignored. Just my $0.02 worth."

The moment of inertia only affects how long it takes the wheel to get up to speed. That energy comes from the motor and is stored in the wheel(s) (it is lost to friction etc. when you turn the motor off).

Steady-state power is related to the drag on the surface of the wheel

• sfm (work = force * distance, and power is work per unit time).