That is not a 5 HP compressor at the hardware store as you state. It
also
indeed DOES NOT state it's 5 HP. It most likely states 5 HP "peak" or
"max", or "instantaneous" or something to that tune. This is very
different from 5 HP continuous. I have a 6 HP "peak" shop vac that
plugs into a 110 V outlet. You can do the math. It is not 6 HP
continuous and it does not state this. The interesting part is that
the instantaneous HP rating is usually in very large easy to read font
were the term "peak is usually in small print next to it.

As for air tools. I've used both cheap and quality tools. The better
tools usually do use less air to do the same work. Other benefits
that I find
are that quality tools run smoother with less vibration, are better
balanced, have more power, and in some instances, can be much much
quieter. Some production grade tools have built in mufflers making
use of the tool
much more tolerable for long periods of time. Take a look at Dotco
tools if you
are looking for top of the line. Ebay or second hand shops can yield
used ones
at more attainable prices.

"william_b_noble" wrote in message ...
aaah, guys.... 15 cfm at 90 psi is well within the range of a 3 to 5 hp
compressor - I have a 5 hp quincy that is rated at 19.5 cfm at 160 psi (If I
recall correctly) - on the other hand, I've seen hardware store type
compressors with "5 hp" ratings putting out as little as 3.5 cfm at 40 psi -
the thing to watch out for is that cheap motors don't cost very much (to
coin a phrase), so these "homeowner" compressors use a small compressor
(because compressors are expensive) and a too-big motor - Lots of these
units (see the ones at harbor freight, or home depot, etc) that have 5 hp
motors would put out almost the same amount of air with a 3/4 hp motor. So,
ignore the horsepower and look only at CFM/pressure to get a true picture.
(and, I have my compressor on a 20 amp/220 circiut - you certainly don't
need 30 amps)


"GTO69RA4" wrote in mes sage
...
I realize this is a valid point, but I'm always surprised that folks
concentrate on CFM so much. I built my own compressor from dumped parts.
Probably about 4 CFM into a 20 gallon tank.

I just grind for a minute then go get a drink of water and beat the dust
out of
my pants as it charges again.

GTO(John)

I'm more worried about the air supply you will need. The die
grinders vary from about 7cfm to more than 15 cfm. Cheaper ones
seem to take more air. And 15 cfm at 90 psi is a LOT of air.
Think 30 amp/240 volt circuit.