Hi John,
I ordered my cylinder and it should be here next week.? ?I just wanted to provide a part number for those who are contemplating purchasing a cylinder.? ?I don't think $64 is bad for a new cylinder.
I agree, if you have access to an excess cylinder, use it.? ?I like the Parker cylinder for it has two ports on the shaft side of the cylinder.? ?This is exactly like the one used (I'm pretty sure) by SawCyl which allows you to have the gas accumulate on the non shaft side of the piston (which makes for a very uniform descent of the saw).? ?The stroke required is something like 2.75 inches (if I recall correctly) and the displaced volume of the shaft is equivalent to 1" of piston travel.? ?A 4" cylinder is a nice size for getting the proper displacement and a 1.25" diameter piston is a nice compromise for keeping your pressures down for the insertion fittings and check valve.
I think you are correct though, if you use ATF, most cylinders should be seals compatible with most the fluid.? ?ATF is not compatible with a lot of the plastics on the john gust insertion fittings though.? ?I am not going to use copper tubing, but I would like to use plastic tubing, have a gage, a ball valve, check valve, and needle valve.? ?The elbows, Tee's, needle valve, and ball valve should be metal.? ?The check valve can be nylon (which is compatible with ATF).
Dave
