Awl --
First, thanks for the replies to the earlier thread. The calcs were very inneresting, and indeed, power calcs are really just applications of newton's laws, F x d, and F x v, as I now see.
The Q is basically this:
Given a standard manually operated bottle jack/cylinder, is it straighforward to add air power, or a hydraulic pump? It seems that the air bottle jacks in the previous link I supplied, as well as one carried by HF ($79) are pretty simple, or they wouldn't be so cheap.
In fact, in those air units, you can use air or manual hydraulic operation.
I have the pumps from a car lift, and a nice 50 ton bottle jack, and it would be nice to be able to hook those up.
Also, in this type of conversion, what are the pros/cons to using air vs a hydraulic pump on a manual hydraulic bottle jack?
Is one better ito of fashioning a "quick return" or an automatic return (upon hitting a stop or sumpn)?
Any DIY sites that show this, and some of the hardware req'd?