How do you control the length a piston will extention/retraction?

[Daniel_LaFleur]

Originally Posted by squirrel

You cannot accurately control the length a piston will extend, if there is a load on it, because the air in the cylinder acts like a spring. You're better off using a motor instead of pneumatics if you need to have good control over how far something moves.

The neat thing about this year's game is that for the most part there is no need to have good control over how far something moves...I mean, the game piece is 40" across, and it just has to go over or under the overpass, it doesn't have to be any specific height. We're using pneumatics that are either up or down for our 3 ball manipulator mechanisms.

With the current KoP parts, this is correct, However, Both Bimba and Parker have cylinders with potentiometers built into the cylinder that give positional feedback. Either of these, used with a pressure controller, could be used to control the stroke of a cylinder even under load.

And this is why I don't like the pneumatics setup that FIRST requires us to use, as it really limits creative pneumatics.

[MrForbes]

Originally Posted by Daniel_LaFleur

And this is why I don't like the pneumatics setup that FIRST requires us to use, as it really limits creative pneumatics.

I look at it the other way...it forces you to be more creative in your use of pneumatics!

And the limited compressor/storage capacity makes you have to think even more

.

[Daniel_LaFleur]

Originally Posted by squirrel

I look at it the other way...it forces you to be more creative in your use of pneumatics!

And the limited compressor/storage capacity makes you have to think even more

.

LOL.

Oh, we can be as creative as the next guy ... No doubt about that. It's just tough because i do work for Parker and I know what is commonly (an uncommonly) available, and I see the restrictions on pneumatics that the students dont even know exist.

I guess my point is First should only limit the amout of power available to pneumatics (limit the working and storage pressures, and the overall maximum volume). That way we could see the real power of pneumatics without having to re-invent the wheel each time.

JM(NS)HO