3 position cylinders from bimba, legal???

I found 3 position cylinders from bimbas website (See this PDF! {584kb}) and i would like to know if these are legal or not.

I believe not. According to the flowchart in the rules:

Is the part a safety hazard? >-no-> Is it a bumper? >-no-> Is it a decoration? >-no-> Is it a kit part? >-no-> Is it pneumatic? >-yes-> Is it ordered from the custom cylinder order form? >-no-> Is it a fitting or valve rated for 125psi? >-no-> Is it a previous year’s cylinder? >-no-> Is it identical to the ones on the custom order form? >-no-> It may not be used.

I could be wrong on the custom order form issue, but I think my statement is sound.

Good luck,

If you are looking for multi positioning on cylinders. There are old threads that have many ideas, search for multi positioning. Basically you need two things a way to sense where your mech is (a pot works well) and a way to stop air on all ports. SMC makes a legal valve body that does extend, retract and all ports closed. We used it on our 2004 bot and it works wonders. Good luck I searched for you this is what we did “What our local supplier has is a SY3340-6LOU The second three in the number is what tells you it’s a 3 position closed center valve, the 6 indicates 12volts. We got two and they bolt right on the body with the fittings on them, they are not pulsing and they only will “pull in” with the correct polarity, red to positive. This solved our problem, we were having trouble with our piston action not being to go from down to up, once started down you had to go all the way down. I think this is do to the nature of pilot valves. Any way, on our pretend-a-bot programming table this valve works great and we got them at about $60.00 dollars as we didn’t get the wires or the fitting body. We are also putting the flow control fittings on the ea and eb holes on the fitting body and can have different speeds for up and down.”

another way: use a clutch on the moving mechanism. When the piston is at the desired postion lock the clutch. This would allow you to stop a piston anywhere along its travel.

lots of stuff on this in older threads - search on: multi position pneumatics cylinders…


you can also use two of the kit valves for positioning, one to control the direction the cylinder moves, and a second to ‘vent the system’ to allow movement.

Or if you need 2 fixed positions, use 2 cylinders connected end to end, one for each position.


<R99> There is no limit to the number of solenoid valves, air cylinders, pressure regulators, and connecting
fittings you may use on your robot. They must, however, be “off the shelf” pneumatic devices rated by their
manufacturers for pressure of at least 125psi. Besides the “free” pneumatic components listed on the
Pneumatic Components Order form, you may purchase additional air cylinders or rotary actuators, however,
they must be identical to those listed on the Pneumatic Components Order form (i.e. same part numbers), and
obtained from a Bimba or Parker Hannifan distributor.

If its not on the “Pneumatics Components Order form” which its not, you can’t use it. Its a lame rule that stifles creativity

beliveit or not last year we had an off the shelf bimba cylinder controling our ball dropper and in toronto they let us us it but in atlanta they made u change it out for a bigger bore longer stoke so all iam saying is mke your bot so that it can accomadate other pistons

Rickertsen2 is correct. 3 position cylindes are not on the Order Form and thus are not legal. It is possible for these things to be missed in inspection, sometimes at muliple competitions. So you might get away with it, but do you really want to take that chance?

On the relative stupidity of the rule: I think it FOSTERS creativity. Look at the threads mentioned above and see how many creative ways were used to get three position functionality. There are other rules I think are relatively inane, but this is not one of them

Watch out guys be careful and check the dates of some threads you may be posting in. Like this one some can be from last year or even older.