Any 2-ball catapult design

Does anyone have an instructional video or directions on how to create a 2-ball catapult? I have a small group that would like to know how to create it. Using version V5 motors. Thank you in advance!!

This is a vex IQ discussion but I assume you mean edr.

Thank you…EDR yes

I was searching and found this video that I think might be of some use to you.

That explains the mechanism, but modifying it to have it hold two balls shouldn’t be too hard.

Hope this helps.

Honestly… asking for instructional video or step by step guide is generally frown upon.

Just few days ago there was a team from UK that messaged me to ask for some tips to finetune the catapult.
Now that is perfectly fine, in fact the forum will be a lot more helpful if you can highlight the problem you are facing, etc.


Honestly…you sound like a for profit individual. Reaching out to individuals that have already been successful in what they do builds more excitement in kids because it is proven to work and see the end results. Thank you for your opinion.

Sharing ideas is what this forum is all about. I’d start by searching the forum for “2-ball catapult” or “double catapult.” There has been a lot posted on this, especially early in the season. Good luck.

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Thank you Rick. Will have my kids search the web.

Honestly… Meng is one of the most senior and respected members of this forum, and he is not a “for profit individual.” But he is right.

Screw for screw copying another design both defeats the purpose of vex and is arguably unethical. If your kids think it’s fun to follow instruction manuals, tell them to switch to Legos.

If your kids have specific issues with their catapult (can’t hit both flags, too big, not enough torque, etc.) we’d be happy to pitch in our two cents, but you can’t expect people to give you instructional guides.


There’s quite a bit that goes into a 2BC (as it’s been called sometimes for shorthand reference). Once we know more about the goal and final design, it’ll be easier to help. Until then, see if you can get your kids to come up with some stuff on their own. Personally, I learn more from figuring stuff out myself than from instruction manuals.


For example, I’ve never even actually built a screw-for-screw clawbot. I had to build one for a camp last summer, but I threw in my own ideas and improvements, the most significant being a much better battery holder and more stable base.

I’ve also never actually copied an exact design save for being required to for a class. I always change something, whether it be aesthetic or functional. I suggest the same to others. It’s a part of the Engineering Process.

I expect to see more reveals as we get closer to Worlds of top tier 2BCs, among a plethora of other designs. You’ll see lots of variations on the design as the season is right now. (Front-loading, back-loading, size, angle, etc.)

For profit?
That’s strange… last that I checked, nobody pays me anything for my comments in the forum, and nobody pay my kids anything for sharing their designs.

I was giving you suggestion on how to get the best out of the forum, ultimately it is up to you to take it, but don’t go around and accuse me of doing all these for profit.

PS… if you search the net or the forum for 2bc, most likely you will see videos from my kids, feel free to take a look, and yes, we don’t charge.

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