Catapult Release Mechanisms

Does anybody have any ideas about how to make a catapult that has a high fire rate (at least one star every two seconds) and can be held at the bottom position for an extended amount of time? I was thinking about a BNS type catapult, but it is pretty inefficient because you need a stroke up and a stroke down every time you shoot. Also, slip gear mechanisms are not easily held at the bottom position. A W&D catapult doesn’t seem like it would be strong enough, but I could be wrong.

Theres a forum for this already with over 160 posts, there are tons of ideas in there, have fun.

With a slip gear, if you find that the catapult rolls back, you can add a worm gear on the slip gear axle. Worm gears cannot be back driven, although they can be stripped. They also offer very low gear ratios, so you will probably want to gear the motors up before the worm gear.

Its not the rolling back, its the fact that you have to lower the catapult slightly more than the resting position to release it.

Oh. Well in that case, you can disengage the motors with pneumatics, but any passive release design will have that issue.

I would recommend something called the “Choo-Choo” linkage it’s used in FRC sometimes for catapults, and works well, again, you might find that the catapult slips back, but you should be able to resist it with motors. A quick google search for “FRC choo Choo” will give you what you want

I have no idea why everyone is focused on catapults when the objects need to only be thrown a few feet???

1.5lbs. going 5 feet needs about half a newton of force.
or 1/2 a meter per second^2

This will be meet with less extreme means than a catapult.

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This is the Choo-Choo hes talking about. It seems legit but the way this guy made it is making the robot jump.

Yes, but also in some other conversations we were talking about how the easier it is the easier it will be, well catapults arent the easiest but they are good and fairly easy.

that is vicious, seriously I dont think anyone will need that much power but some people may use the basic idea.

I think you’re right, but catapults are the most efficient idea we’ve come up with so far.

Not really, dumping will prove to be very efficient.

My team was thinking along those lines as well, but we thought that it might be slightly slower. Im not sure though because we haven’t prototyped yet


Dumping does seem easier and faster as you can just make a scoop and a lift to dump stars over, but consider the fact that getting the stars in the far zone doubles your points, basically making it more worth to get your stars there. Its the same as nothing but net. Though low goal was easy, all the high scoring team usually did high goal.

If it takes you twice as long to shoot the objects instead of dump them than it wont be worth it, but if you make a launcher without elevating than you could do it faster because you dont have to elevate your launcher.