Catapult Pneumatic Boosting Reservoir Question

Our team has been struggling to understand how to disengage our catapult’s pneumatics after the autonomous period using 2 connected tanks. We had it work with one reservoir attached to our expansion, and one connected to our catapult. We would release all the air out of the catapult’s reservoir to turn it off, but we were wondering it would be possible to use two reservoirs in one connected system instead. We want more air in our expansion. We tried using 3 solenoids and we are using 2 double action pistons.

This video by 606x should help

Vex Hex doesn’t detail how the pneumatic “disconnects” from their reservoirs. That’s been our biggest issue.

They’re using air pressure to push the pneumatic double acting piston back. Simply connect only valve A of a double acting solenoid into the retract end of the piston and valve B should just be blocked off or connected back into the air source using a T-valve. Then, when you withdraw air from the end that was connected to the boosting piston and open valve B, there will be no air pressure to the piston, and it will no longer create longer shots. Activating valve A again will activate the boosting system.

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Are you allowed to block off valve B using a motor screw? Or is there another part?

“allowed”…does it say you can’t in the Game Manual??? Will it work…no.

To plug a pneumatic port in the solenoid valve, you need to use or make a plug. Take a length of tubing, heat it carefully in a spot with a match or lighter, and as it softens/melts, pull and twists it to seal the tube. Now you have two plugs.

You are not allowed to melt a part like that, what you can do is fold it over itself and ziptie it down which if done right should keep air from escaping


Right, can’t melt tubing…we used to make plugs like that all the time when I was working for La-Z-Boy…so I didn’t think anything of it.


You can also block by feeding the tube out of valve B into a T-valve, where the other two ends connect to the reservoir and the solenoid input, respectively. I would recommend this, since we have had problems with leaking plugs using folded tubing.

A smarter way to do this would be to use a single acting solenoid, instead of a double acting solenoid, while still using the double acting piston. Then, no sort of blocking or extra tubing is necessary.

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