When you say "radial", I take it to mean that you want a piston compressor
with a number of cylinders radial to the crankshaft. The rest of the group
appear to think "centrifugal". You can probably build a "radial " machine,
but a fractional horsepower centrifugal compressor is not a practical
machine. Commercially made centrifugals tend to be 500 HP and above. Screw
compressors are now becoming available in smaller sizes,but, again, there
are few under 10 or 20 HP. You can probably buy a Chinese made compressor
for far less than you can build it for even if you already own the motor.

"Littleberry" wrote in message
om...
I would like to make a small homemade radial compressor in my amertuer
machine shop. I have a 3/4 hp electric motor (12 amps, 110v, 3600
rpm) with a 5/8" shaft that I would like to use to drive it. I don't
know where to start - can I expect a 3:1 compression ratis? I wonder
what kind of cfm at 45-50 psi I could expect.
I also wonder what kind of profile I should use for the fins, and how
many fins I should configure. Is there public data as to various fin
profiles verses efficiency and compression ratios? I am gueessing
that the compressor should probably wind up being about 6-8 inches in
diameter and maybe 4-6 inches in lenght. If there were plans (already
checked out and proven) I would certainly prefer to just buy the plans
instead of having to work all this out on my own. Any ideas would be
very much appreciated. littleberry