pneumatic arm

[cipher510]

:confused: I am looking for an equation that will allow me to raise an arm using pneumatics to any given height by changing the duration of the time the valve is open. Unfortunately :( none of my teachers know the answer as it is beyond what they teach in HS physics and not something they learned recently. I thought someone on here might know how it could be done. help would be appreciated

[cipher510]

nvm i'l try yo figure it out on my own i guess...

[powerlabs]

Sorry, just saw your post. Could you be more specific? It sounds like all you need is to figure out the flow through the valve (http://www.engineeringtoolbox.com/flow-coefficients-d_277.html ) and the capacity of your cylinder; the duration of the time the valve is open will dictate how much air is in the cylinder, and that number divided by the volume of the cylinder will dictate pressure. It gets slightly more complex because you need to know how much pressure you need in the cylinder to get it to move the arm, but knowing that, the height becomes a simple issue of airflow vs displacement.