Motor Pulley Diameter Question

[Dobroguy]

For those who use the Shop Fox buffer .............
What size motor pulley do I need to get an acceptable (safe) buffing speed?
My wheels are 12" diameter and I will be picking up a 1/3 HP motor tomorrow from a friend in the big city.
I hope to complete my buffer tomorrow.

S.F.Buffer.JPG

[MaineGeezer]

The thing you need to worry about is surface speed.
According to this article https://www.finewoodworking.com/forum/b ... revolution. you want about 3500 surface feet per minute (sfpm)

If those are 12" diameter wheels, you have 3.14 feet per revolution, so to get 3500 sfpm you want 3500/3.14 =1115 rpm. If your motor is the usual 1725 rpm, you'll need a motor pulley about 2/3 the diameter of the buffer pulley (1115/1725 = .65)

[Dobroguy]

I knew someone would know the answer and make it simple to understand.
The thing is, after reading your signature statements, should I believe everything you know? (wink).

There is precious little information about this in the instruction book.

Thank you!

[tippie53]

I use a 1 1/2 in on mine with the 3 pulleys you will be fine
I use 14 and 16 in wheels
https://www.youtube.com/watch?v=uhPyTyThacE

[tippie53]

here is my final results. I also use a hand deal action hand buffer. If you look close as you use the wheels, if you see the surface getting smearing you may be using too much material. You only need enough to do the job.
Here are the wheels I use . I can't say this enough , as the surface gets shiney you will see the smaller defects. Its a process. Take your time .
https://www.jescarguitar.com/buffing-wheels/
if you need to shim the arbor to fit the larger wheels. I use tape. Big A auto had pin strip tape. That does a perfect job or even some plastic pipe cut offs work.

[Dobroguy]

Looks great John & thanks. I'll pick up a 2 1/2" pulley while I'm in the city today.
I bought the 12" wheels that Bruce recommended from Caswell. The center holes were slightly too small on one side and wouldn't fit on the 3/4" shaft. So I borrowed a tapered punch from a neighbor to enlarge the holes. Just a couple of light taps and the wheels fit perfectly.

[tippie53]

1 1/2 in

[Dobroguy]

1 1/2" -
Phooey, I should learn to read more carefully. I just installed a 2 1/2"er yesterday.

[Bob Gleason]

Can you put that in an actual formula format to get from motor speed, pulley size on the motor and shaft, to the FPM of a buffing wheel of what ever size? I knew that stuff when I made my first buffer, but the info is buried somewhere in my filing system, which is actually no system at all! Much appreciated.-Bob

[tippie53]

PI X D = Circumference
so lets say you have a 12 in wheel 12 X 3.14 = 37.68 in
so this times the rpm so lets say your at 700 rpm
700X37.68 = 26320 in per min divide by 12 for feet per min 2193 ft per min

https://www.pfonline.com/articles/buffi ... -for-speed