The way every one is rating HP these days are very misleading. I have a 2HP that will keep up with most of my air tools. It's rated at 8.8cfm@40psi, 6.3cfm@90psi. Most air tools use between 2-5cfm@90psi. But it's a true 2 hp, pulls 15 amps on 110, or 7.2 amps on 220 (what I use). I bought this compressor 30 yrs ago for painting. Back then most paint guns only used around 6-8cfm at 30psi. Lacquers are light thin material and easy to spray. The HP use to be a valid rating. Now there measuring the overload peak as HP rating. It's next to impossiable to run a 5hp motor on 110v. Amperage would be in the neighbor hood of 40+amps. Your not going to run in on a 16ga power cord. Shop Vacs are another one that are not rated correctly.bearandoldman wrote:Very good description Smokey, the 5 HP compressor we had would not keep up, maybe a 10 HP rotary compressor would, but they sure do work nice. With the reinforced disc they are great for cutting off screw without leaving a burr so they will start easily as if new.
I have been looking at new compressors, its very hard to get any valid specs from most. You definately can not go by HP. Years back you could use 3cfm/hp. I think you can still use that formula if you go by amperage to calculate actual HP. With my HVLP gun use 18-24cfm@10psi, 50psi to the gun I may just rent one. But you are not spraying 100% of the time, more like 70% if your covering a large surface.
Now back to the Dremel grinders. The best ones I have used was a Foredom cable drive systems. You have several hand pieces that allows you to go very small for those hard to reach places, or you can use the std chuck hand piece. They have the collets hand pieces too, but the miniture check sure is nice.
I currently use a small 54k mini air die grinder, only uses 5 cfm with max rpm. But in most cases I do not use it at full speed, close to 25%.
Which every way you go opt for the variable speed model. Gives you a lot more options, particurely if your going to use any diamond cutting tools.