This is something DBlue135 and I built this summer for the XtremeSystems Autocascade Competition.
We used a 1/2 hp rotary compressor, R22, a fairly standard condenser, a home-built water-cooled condenser/phase seperator, etc.
Both stages return through a slhx to help the second stage condense.
The first thing we did was build the main heat exchanger.
http://www.baughman-eshbach.com/autocascade/1.jpg
Then we made the coils for our water-cooled condenser. These are 3/8" copper pipe and DBlue tells me it was not very fun to bend these:
http://www.baughman-eshbach.com/autocascade/2.jpg
We then put the coils together and added their inlet:
http://www.baughman-eshbach.com/autocascade/4.jpg
Then came the first version of our main seperator, which looked like this:
http://www.baughman-eshbach.com/autocascade/5.jpg
We decided the volume was too low so we rebuilt it. We also constructed the housing for the water-cooled section:
http://www.baughman-eshbach.com/autocascade/9.jpg
We picked up a cheap base board and gave a it a coat of blue spray paint. It's big enough that we don't have to be too careful with our layout, there's a lot of space. We mounted the board on casters and mounted the first few components to the board:
http://www.baughman-eshbach.com/autocascade/10.jpg
http://www.baughman-eshbach.com/autocascade/11.jpg
And we mounted our water cooled condenser and base to the board.
http://www.baughman-eshbach.com/autocascade/16.jpg
