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Unread 29-03-2011, 23:20
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Re: Solution: Variable position of cylinder in compliance with <R74>

Quote:
Originally Posted by Roboman01 View Post
Are you sure it's a center pressure valve? Also, when you were moving the cylinder, did you need to adjust the regulator to change the position of the rod, when it was not at either extreme?
The requirement to hold the piston in place doesn't change as the piston moves along the cylinder, stopping it half way is the same as stopping it one third of the way out. The sum of the forces must be 0 to maintain constant motion or to stay at rest. If the regulator is set at a constant setting that balances the forces resulting from the pressure pushing against the 2 surfaces of the piston, which have different areas, then friction will quickly bring the cylinder to a stop and keep it there. The accuracy of such a system decreases with momentum.

You seem to be confusing volume or surface area of the inside of the cylinder with force exerted on the piston. The force exerted on the piston is what matters, the other two are irrelevant.
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