Catapult vs Wheeled Shooter

I’m curious on what went through your heads when you were deciding between a catapult and a wheeled shooter when designing your robot. Team 3072 went with the wheeled shooter so that an opposing robot couldn’t hit us hard enough, then dislodge our ball out of our shooter. I’ve noticed about an equal number of top level robots that have both designs.

Our decision was based on past experience with rebound rumble - that year, there was so much variability with the balls that wheeled shooters had a real tough time being consistent. We assumed it would be the same with these balls!

I think you mean Rebound Rumble :slight_smile:
Breakaway was 2010 and used soccer balls!

edit:: and although I’m not on a team and don’t have to build a bot, I would probably have gone towards a wheeled shooter design. Having seen both in competition that worked well, I think the wheeled design has more flexibility for shooting position, accuracy, and power.

Catapults are more reliable and accurate, and are also amazing at batter shots. However, wheeled shooters can swivel on a turret (254 style) and have more angles of release. With catapults usually you can just get 2 different angles of release. Plus you have to worry about the ball falling out of a catapult. That being said, I have seen extremely successful robots with both types of shooters.

We went with a wheeled shooter this year, and it worked well, but as the balls got abused it lost some of its range. As most years it was a learning experience.

My team went for a catapult, because

the loading time was not an issue, since we could only shoot one boulder at the time.
It is also faster to shoot, since you don’t have to get a flywheel to a certain speed before shooting.
It is more precise, especially with worn off boulders

I find it interesting how certain shooter designs this year seemed to vary heavily by region- for example, Texas has a bunch of amazing catapult robots (118, 148, 2848, 4587), but California, in contrast had no top-tier catapult bots (correct me if I’m wrong), with nearly all the top teams (254, 1678, 971, 973, etc) opting for flywheel shooters.

We went with a two wheeled shoot because of our experience with catapults in Ariel Assist. By the end of the competitions, the catapult was struggling to maintain accuracy. We also figured we could integrate more systems into a wheeled shooter system such as a collection system and a scaling system.

We had two main competing designs during the first week: a single wheel turreted shooter for batter/midrange shots, and a catapult for shots from the outerworks.

Initially the entire design team was leaning towards the turreted shooter, but we built prototypes of both concepts and weren’t happy with the ball to ball variance of the wheeled shooter. We were worried about aiming accuracy for the outerworks concept as well, but the catapult prototype showed good repeatability and was able to hit the target at that distance, so we settled on the catapult.

Then we wasted half of our build season on a drivetrain.

I would say 4 of the top 5 bots in MN are catapults, but the best robot, 5172, is a flywheel.

A very good team, given enough iteration and development time, can make almost any design competitive.

However, I think it’s pretty clear that catapults were the way to go this year, in retrospect, unless you really needed the packaging benefits of a wheeled shooter. Catapults could more easily shoot consistently and could more easily be built to shoot over a defender from the outer works.

Yes you are correct about CA. I can’t think of any consistent catapult shooters here. I think a big factor is the use of vision tracking (thanks to the assistance of 254 and 971). Wheeled shooters give a more consistent straight line shot that allows varying distance. Catapults appear to be more dependent on a set distance.

We pretty early on leaned away from a wheeled shooter since we were worrying about ball consistency and we didn’t think we would need very fast shooting times. We made a pretty consistent pneumatic catapult in 2014. We are pretty good with catapults so we decided to stay with it this year.

I think 401’s shooter was deadly, and pretty precise.

3072 had a couple positions of being able to shoot at different positions on the field, so we could make it from the outerworks, all the way to the batter. I’d be confident if we could shoot from the neutral zone on making it. Our prototypes for our shooter vs catapult were heavily on the shooter side. We just never got there with a catapult.

We know how to build, tune, and debug a wheeled shooter, and they’ve been good to us in the past. We don’t know how to build, tune, and debug a catapult. We could probably figure it out, but early prototyping showed that a wheeled shooter could get us the performance we wanted, so why do something else?

I am guessing that many of the Texas teams had the exact opposite experience.

I feel like 401 can agree that if you wanted to add a fourth adjective to their shooter, it would be “temperamental”. Wheeled shooters, unless nearly expertly honed in, can be temperamental. When they are on a roll though, watch out.

Citation needed?

If you look at the top 20 teleop high goal OPR teams, only 5 of them (195, 1024, 118, 148, 230) are catapults.

If anything, side-by-side dual wheel shooters a la 971, 987, and countless others were the way to go this year.

A few things that wheeled shooters have over catapults:
-Ball protection
-Ability to be on an arm
-Familiar (2012)

Catapults definitely have consistency among other benefits, but I disagree that it’s cut-and-dry catapults over wheels.

Catapults can definitely be on an arm :wink:

Cause we so fly in Cali

There are two really good catapults going to champs from California: 1836 and 5124.