Thread: Optimizing Precharged Cylinders
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Unread 26-01-2010, 01:41
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Re: Optimizing Precharged Cylinders
Quote:
Originally Posted by PerpetualMotion View Post
Assuming you are using air tanks, the pressure will stay constant throughout the extension of the piston and as such, there would be no need to "pre-charge". This significantly decreases the size of the piston (by .368).

However, the math is absolutely correct, and very insightful. If you do not plan on using air tanks for whatever reason, pre-charge your piston 1/3 of the way.
This is not correct because the Solenoid valves are a bottle neck in the system. With a CV* of .32 (max) the rate at which air reaches the cylinders it not enough to make up for the Boyle's law decrease in pressure. Precharged cylinders almost always have more "power" than regular cylinders for this reason.


*the flow of water through a valve at 60 oF in US gallon/minute at a pressure drop of 1 lb/in^2
Definition taken from http://www.engineeringtoolbox.com/fl...tor-d_238.html