Official Luthiers Forum!

I was in Harbor Freight (tools) today and saw a 3/4 hp grinder/polisher (8"). I was thinking of taking the grinding wheel off and replacing with another polishing wheel. This is a big, heavy duty, long axle device. $69. But I want a 10" wheel(s). Can this motor handle (for this kind of work) the 10" wheels?

Mike

It turns too fast, and will burn the finish. You want 700-900 RPM.

Al

to fast and you would get into other problems. If not able or want to get arbor, motor and materials to do a buffing thing now, Use a drill with the attachment to do it. As good as a wheel no, will it do the job for now and make a decent finish you bet

Oh, I want an arbor now! Thats why I am asking. That rpm thing is GOOD info. Got a reccomendation?

Mike

caswell plating has an excellent all in one buffing machine which operates at the appropriate speed and are offering in kit form including 6 buffs, several compounds, wheel rake, etc, at a very good price. well worth a look.

I think I`ll stick to Robbie`s car polish and a rag.Real cheap set up and looks pretty good to me.
             James W B

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James W Bolan
Nashville Tennessee

I have a friend that is an HVAC replairman, he can get me 1/2 hp motors that do 1725 rpm. Anytime furnaces are replaced, the motors can be scavanged. I use one to buff my pistol grips, but thats raw wood--I imagine its too much for buffing a finish?

OK, been doing a little research. Turns out that motor speed is based on a simple equation: 7200/# of poles in the motor. 2 poles are very common resulting in unloaded rpm of 3600 (loaded is 3450)...4 poles is 1800 or 1725 loaded. And so on. Question I am having now is would a Variac be usefull here? I am guessing not since motor speed is a function of AC frequency...

Any EEs in here?

Mike

Here is the buffer I made copying one I saw on www.frets.com a tour of CFox Guitars years back. His buffs were sixteen I'd say, mine are only 12.

I recommend the softest buffs you can find. I tried some airway buffs and prefer the concentric sewn. I want to change out to a loose buff and see if I like those better than airways.

Here is a link to the JIGS area on OLF where you can find this buffer and much more:

http://luthiersforum.3element.com/pages/jig_tools_tech/jigs_ tools_tech.htm

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http://www.dickeyguitars.com

variac won't help you. easiest method of speed adjustment is to use a 1725 rpm motor and reduce using 2:1 pulley ratio. combined with 12 in wheels give the appropriate buffing speed at the wheel rim.

Thats what I thought... Bruce, nice pics... Thanks!

Mike

Mike,

Caswell has an 1100 rpm buffer...is that OK? Seems like the desired speed is less than 1000 rpm... But if 1100 rpm is ok, I'm gonna get that. Is that what you use? (space is at a premium for me now... so a speed reduction pulley system may not work)

Mike

no, i built mine years ago, a go kart axle, bearing blocks and a wooden frame, scrap 1/4 hp motor. i just had to replace the motor a few months ago. i was lucky and found a 1/4 hp explosion proof on ebay for less than $10.00. explosion proof is not necessay by any means, but if you decide to go for a separate motor style drive arrangement i would recommend using a tefc motor. buffing generates gummy dust, particularly if you use waterbourne finish.

if i were starting out i would probably go with the caswell outfit. it is a good deal.

there are several folks on the forum who have the machine and speak very highly of it. it is on the upper end of the "good" speed range, and given its power you have to be careful not to push the stock too hard or you will burn it.

aside from low cost, that is just about the only advantage of a small motor/pulley drive. it can be set up so it will stall if you push too hard.