Converting Double-action to Single-action

I am new to the VRC and also new to pneumatics on Vex. Quick question, is there a legal way to convert a double-acting solenoid to single acting by plugging the second air output?
I know you can buy plugs for the solenoids, but not from vex, so I imagine that would illegal.

For the cylinders you can just leave off the valve from the side you do not wish to power.
For the solenoids, you can plug one of the valves by putting a small piece of pneumatic tubing in it, bend it over into a kink and ziptie it tightly.

“Convert”? You can’t add a spring return to the inside of a cylinder legally, no.

But you can just use a double acting cylinder as a single by only plumbing air to one side and allowing gravity / external surgical tubing / etc to actuate your mechanism in the other direction. Just leave the unpowered end open so air can freely escape. This may even work better for some mechanisms than a single acting spring return system.

Sorry, I should have been more clear about what I meant by convert. I was thinking of how to block the second solenoid output. I will edit my post to be more clear.

This is what I was asking. Is there any other way, or is this what other teams are using?

1 Like

That’s the easiest and probably best method, aside from proper plugs, but those aren’t VEX parts. It’s like bending a garden hose to stop the water flow, which is generally quite effective.

Alternatively, you could use a t-fitting and create a loop with tubing, but that’s just more tubing that you will lose air in.

Actually, those plugs are competition legal. The old pneumatics kits used to come with them, and discontinued parts are still legal. I’m having trouble finding the part number, maybe someone still has the old contents list, but I think it’s this one.

Yep we still have competition legal plugs from the older pneumatics kits. They can come in really helpful when building more complex pneumatic circuits. Can post a picture of one when I get back to school if you need, but I think the one Kevin linked is correct and as its an identical part, it should be legal.

Great, thanks everyone!