Endgame string expansion

Right now we have a 2-motor shooter, intake, roller, and 4-motor drivetrain. This does mean that we have used up all 8 of our motors. However, we do have access to string and pneumatics. We were just wondering if anybody had an idea on how to build a good string endgame powered by pneumatics.

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I’m not an expert on building, but for coding, it depends on if they are single or double action pneumatics.

Single-Action: First, add an LED (under the 3-wire category) in your devices section. Make a forever loop and if/else within it, (I.E. if [Button] pressing)
make it so that IF, your LED turns off, because off = valve or something releases, firing pneumatic, and on = the opposite.
Make the else turn on the LED.
Double-Action: The same, except use DigitalOut (also under 3-wire) in your devices section instead of LEDs. Also, instead of off and on, it is “set false” and “set true”
False = off, true = on, same “reverse” dynamic.

(This is a C++ guide, not sure how well it would do in blocks because of the lack of Pressing and only Pressed.)

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What I have seen are catapult launchers using pneumatic to release the mechanism.

Should be plenty of YouTube videos.

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Ok thanks I will be sure to look into it.

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Thank you for all of the advice I will, try to translate it into block code.

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I highly, HIGHLY encourage you to switch to C++. It is more reliable, and will later be your only choice when switching to VEX PRO. It is much more versatile, and easier than it seems, and not too hard to learn with enough backing. I learned it myself, and it is my first year.

However, in the meantime, for a blocks code, this should be the closest you could get, will probably work, but don’t quote me on it.

I may or may not have the digitalOut “low” and “high” reversed, as it is different from true and false.

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Thank you so much me and my team our very grateful.


Go to the three wire and do digitalOut since that’s whats meant for pneumatics. If you’re in vex code pro you can use true and false boolean values or if you’re in block code I’m pretty sure there’s a high and low value that you can use instead

Yeah, I figured that out after this post, it’s better to do digitalOut for both rather than digitalOut and LED @Robo_Raiders_85403A

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This is a great string expansion by 67101C centrifuge: 67101C Vex Spin Up Endgame Expansion Explanation - YouTube. However, it uses yarn instead of the required 1/8" string. Another great one by 21417A gets almost every tile, but requires several pneumatic piston: 21417A 2 Cylinder Endgame Explanation #spinup #vexrobotics - YouTube. Hope this helps!


STRONGLY recommend putting a lockout in the code so it CANNOT trigger before the final 10 seconds in the match. Otherwise… you’re looking at anything from a penalty, entanglement, or DQ.


Thank you everyone for everything we think this will greatly help us at our competition.

How does one do that?

I would use a waitUntil ()or some other timer wait system to wait until the under the 10 seconds for the button press to be able to do anything.

You need to delay the ability to deploy until the final 10 seconds, which is 95 seconds after the ‘driver control’ starts. Looks like you need a simple ‘if’ statement tied to your deployment control.

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