Pretty sure Nick Muller already did this and has the dimensions on
his web site...maybe Don Foreman will post link....

Thanks, found it...
http://www.metalworking.com/DropBox/
http://www.metalworking.com/DropBox/...ri_sketch2.jpg
http://www.metalworking.com/DropBox/venturi.txt

I just wanted something quick and cheap, but I'll look into
the fridge compressor if I get my hands on one.

Thanks,
Tom.
http://www.TomEberhard.com