So I have been thinking about a double catapult, but I can’t seem to find a video with a robot that uses them. Does anyone have a link to a video? Thx.
It’s inside here…
Thank you meng
In honest opinion, I find it not useful to build a double catapult. The issue with it is the accuracy. Being a catapult, it may fire off centered if loaded incorrectly and not perfectly straight. It may also requires specifically non-damaged balls to launch since it might curve off-centered. Overall, I would not pick a catapult as a launching mechanism but rather would pick a pitching machine or something of that nature.
Hearthy–7517J
I agree a double catapult would not have that much accuracy. Therefor i would personally use a pitching machine to do the task at hand. Plus it would have more accuracy and easier to shoot.
Having just finished my double catapult I strongly disagree. When lined up properly a double catapult can be extremely accurate, we hit 83% in our test and the 17% was due to me accidentally bumping the bot and angling it. With a gyro to help align a double catapult would be almost 100% consistent.
I haven’t built any sort of catapult but all of these issues are fixable or also apply to every other shooter. I feel like catapults are actually very accurate (as @MasterCole said)
From the session we had with the balls over the summer, balls getting damaged is not something I would expect to see. I do expect to see the balls damage other things - wear your safety glasses every where… maybe even a catcher’s mask 
Alrighty, I just built a double catapult and I’ve learned a few things:
- Use high strength axles. It takes a lot of force to fire two balls, one 29 inches and one 42 inches. The rubber bands required to do this will bend your axles in seconds.
- Make sure your the catapult can go lower than the feeding mechanism. You need to be able to get balls from the feeding mechanism, then also be able to go lower so your slip gear will slip.
- Don’t try to use the chassis rail things. The chassis rails bend really easily under the force of the rubber bands, and your catapult will just go out of whack.
- Use antislip mat to stop the catapult. If you don’t you will break the metal lol.
- Use a ratchet. The ratchet will allow the catapult to stay stationary. (Also make sure it’s a good ratchet and don’t stick your hand in the way just because you think the ratchet will hold owww.)
Just my 2 cents
I am being selfish… but I am secretly hoping that I won’t see that many double-catapults when worlds comes around. lol…
I am with you - a lot of speculation without the first hand experience your teams have - a great competitive advantage.