Pneumatics Resources

[TimCraig]

Originally Posted by DavidGitz

Also, I was wondering if anyone had developd a system for controlling the position of the extension of the piston on a cylinder. I found one idea on CD but it used 2 solenoid's, has anyone implemented this concept with just one solenoid?

Here's a recent artice I ran across on the topic about new valves coming on the market to do just that.
http://machinedesign.com/ContentItem...actuators.aspx

As Daniel points out, the compressibility of air is a problem in holding the position. The air in the cylinder acts like a spring and the piston moves as the external forces change. To counter this, you need a feedback mechanism so the valve can rapidly adjust the pressure in the cylinder. Being able to integrate the control electronics into the valve makes it a reasonably priced commodity.