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Unread 07-01-2008, 21:50
Jonathan Norris Jonathan Norris is offline
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Re: controling extension on piston

Quote:
Originally Posted by Don Rotolo View Post
Of course, they also make double-solenoid valves that allow for mid-stroke stops, without the need for single and double solenoids controlling a single cylinder.

The truth, however, is that pneumatic pistons are really only good for all the way in and all the way out. It's possible to do mid-stroke positioning, but it doesn't work well, especially if the load on the piston is large (more than 5% of rated force) or variable.

Don
Don't dismiss multi positioning pneumatics system so quickly. After a unsuccessful arm system in '05 we rigged up our arm design with a multi positional pneumatics system and it worked surprisingly well with heavy use and only two tanks on board the compressor was strong enough to keep up with the load. For a game like this where you will only need two main positions for an arm system, a multi-positional pneumatics system for your arm is a very good option and far easier then implementing a beefy motor to handle the load. Of course there are negatives, the big one being bouncyness, but with a little creativity these problems can be solved.
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