rpm's ? (sfpm)

[mercsvt]

Is it ok to use a 10000 rpm motor, with a 5" wheel to polish aluminum, the problem is I keep burning motors on hand held polishers, and the guy at sears knows me by my first name. the original polisher I was using was like a 4.6 amp 2600 rpm 1/2 horse. I have burned out 3. so I went and bought a 12 amp 10000 rpm hand held grinder. is this going to hurt anything but myself? I am polishing various bike parts, some have sand cast, and i am knocking them down with 120, 180, 240, then black, and brown

[mcaswell]

Re: rpm's ? (sfpm)

It's not hurting anything, but a motor that powerful could handle a much bigger wheel and would get the job done much faster.

[mtlplshr]

Re: rpm's ? (sfpm)

very good question.i have used a 2600 rpm with mixed results.it has a lot of hours on it and i am shopping for a new buffer myself.i have just about decided on a 4600 rpm craftsman sander,and am going to make a mandril so i can mount 4 8 inch wheels side by side(will give me about a 3 inch wide wheel)and do some serious buffin.i have met guys who say they use a 10000 rpm grinder but have never seen one used.i have used my buddies 5000 rpm with a cutter wheel and tripoli and it definitely did a faster job than my 2600 did,without worry about catching an edge and pulling my arm off.its a craftsman too but no longer avail.from sears.the 4600 i'm lookin at is like $109 at sears and looks to be heavy duty(it weighs 12 lbs.!)let us know what you end up getting.thanks

[mercsvt]

Re: rpm's ? (sfpm)

i tried the 10000 rpm toll way to fast, powerful but to fast, i ended up getting the sander you are refering to the sears 1 3/4 horse 4600 rpm it has ball bearings on motor shaft not bushings, hasnt burt after 5 hours of polishing, so far so good on average the cheaper sears polisher before was lasting an hour went thru 3 of them.

[binarius]

Re: rpm's ? (sfpm)

mercsvt wrote:
Is it ok to use a 10000 rpm motor, with a 5" wheel to polish aluminum, the problem is I keep burning motors on hand held polishers, and the guy at sears knows me by my first name. the original polisher I was using was like a 4.6 amp 2600 rpm 1/2 horse. I have burned out 3. so I went and bought a 12 amp 10000 rpm hand held grinder. is this going to hurt anything but myself? I am polishing various bike parts, some have sand cast, and i am knocking them down with 120, 180, 240, then black, and brown

Years ago, when I made jewelery, I used an old 1/2 hp washing machine motor with pulleys to increase the speed. If you set it up for multi-sheave pulleys, you can get several speed ratios. Also, some of these motors are multi-speed. Induction motors are quite indestructable compared to the brush-type universal motors, and you can often get them really cheap/free if you ask around. Of course, the pieces I worked were pretty small, so a fixed buffing wheel on a bench was okay. If you have large parts, or need to be mobile, this may not be an option for you.

fwiw