Shopsmith Forums

Well I have needed a bigger compressor for a while. I have a 3 hp Craftsman that I have used for many years and it still works perfectly but it has never had the power to run most of my air tools from my dealership days. So I have been on the look out for a replacement. I have been constantly keeping my eye on Craigslist and finally I found one. It is a Craftsman Professional 7 hp 60 gallon vertical tank and has a max PSI rating of 175. The CFM rating is 10 at 90 psi and has a max of 12.35. The guy I bought it from said he ran all of his tools with it and had no problems with it keeping up as well as a sand blast cabinet with no issues. So I am pretty excited to get it hooked up. It is 220V so I have to add a 220 circuit in the garage this week to be able to run it. I upgraded the electrical in the garage a while back ago to 100 amp service and have enough room in the box to add the 220 breaker so it should be pretty straight forward and i should have it running in a couple of days. A compressor is something I just could not live without in the garage and I use it all the time so this should be a really nice addition to my dungeon. Oh I only paid $300 for the compressor and from what I could gather that was a pretty nice deal considering the prices of the other used machines and what the new ones go for.

Keep in mind that the 7hp rating isn't true horsepower. It is peak horsepower which doesn't mean anything in the real world. It is a sales gimmick. The 10cfm @90psi tells you that it is really about a 3hp compressor.

My shop compressor is a true 5hp compressor, and it makes 18.5cfm @ 100psi.


In the real world, you get 3-3.5 cfm per horsepower of motor.

But, at $300, it is a great deal.

I snagged a craftsman pro 6hp 30gal 150psi unit from a guy at work for $160...now just need to get some air tools

Gee, I feel deprived now. I have a 1.5hp, 4 gal that has been with me almost as long as the 1st Mark V and I thought it was doing great.

garys wrote:Keep in mind that the 7hp rating isn't true horsepower. It is peak horsepower which doesn't mean anything in the real world. It is a sales gimmick. The 10cfm @90psi tells you that it is really about a 3hp compressor.

My shop compressor is a true 5hp compressor, and it makes 18.5cfm @ 100psi.


In the real world, you get 3-3.5 cfm per horsepower of motor.

But, at $300, it is a great deal.

Thanks Gary I knew all of that prior to purchasing this unit. I figured it would be a heck of a lot better than my 30 ga. 3 hp. 8 scfm/6scfm little compressor that would not keep up with the demand of the air tools I have. I got it all wired up tonight to a new 240 v. outlet I installed next to the main 100 amp. breaker box. It ran without issue and kept up with the demand although it did run constantly once the air was depleted to a certain psi. It is very loud compared to my smaller unit but it does have th oomph to run my tools now. I would have much preffered a unit like the one you have with 18-20 cfm but could not put that kind of dough together right now and this was a smokin' deal as far as I am concerned looking at what was available new/used. I am pretty happy with it and it will make things much more efficient when utilizing my air tools now.