Catapult Effectiveness

I was on the Discord server earlier and it seems that catapults aren’t really viable this year.
Claws (and apparently even pushbots) seem to be doing really well, but my team feels like with some extra tweaks and work, we can build a catapult that can counter both of these.
How can we go about doing something of this sort? How can a catapult grab clumps of stars to counter the clumping that claws can handle?

a catapult has several major problems,

  1. slow cycle times if it wishes to shoot both cubes and stars
    2)low capability in stars if it wishes to have very fast cycle time
  2. (both 1 and 2 can be overcome with lots of motors)
  3. repair-ability- catapults are hard to maintain, more repairs due to stoppers and strain on motors and such, more repairs are necessary
    5)unless you have more than one catapult part such as the one revealed here,( its hard to catapult both stars and cubes (i recommend a choo choo type system rather than this)
  4. driving is hard, if you use the standard standoff method, you cant drive backwards without stars falling off.
    those are a few things, however with some really clever engineering, you may be able to do it. if you do be able to overcome those, then dang, i want to see it

EDIT: idk whats up with the formatting

You might’ve forgotten a link on the word “here”

oh yeah sorry let me find it again

So after a competition, I have realized that a catapult may or may not be the best choice to win worlds… If you have an insanely turbo-ed up drive with a clawbot design, you will be the beast of all competitions… But how would we overcome them? Well… one of the issues with their design is time wasted turning. What you need to do is build a robot that can accumulate way more much faster AND be able to dump in an area that is harder for them to bring to your side. A catapult robot can do just that IF the opposing alliance uses a 4 or 6 bar instead of a 2 bar, and ALWAYS going to the far zone to make time wasted for them trying to drive to the fence and back…

In order to remain competitive, you’re going to need to be able to launch at least 3 stars over the fence at once, so if you also want to be able to launch singular stars you will need a system that can have multiple power modes. We built a choo-choo catapult that sometimes got 3 stars over the fence, we could have made it more powerful but that would have sacrificed our 1 star ability, which was one the fringes. (That robot)(And 3 stars)
I think it could have been faster as there wasn’t a heat problem, but we tripped the internal fuses a couple times. (I forgot to separate the ports)
(I should probably add that we finished this robot before the Gael Force reveal, so it is not a copy, although obviously it is inferior anyway. ;))
If you gave what Gael Force uses an extra 4 motors I bet it would be pretty fast. (With a different gear ratio)

Driving a catapult is a pain, but you can get around the reversing issue by simply lifting the catapult slightly before reversing or turning.

The key to this is choice. Have a bot that can choose between near and far zone, when at any position on the field… when facing forwards or backwards… and something like siderollers… and… well I don’t want to reveal our design too early.
Speaking of reveals, where’s yours @CATaclysm Delta_II ? I believe you said you would have it out soon. (monday)


5327C’s pincher thing design could help in pulling stars out of clumps.

I figure I’ll just post a kind of crude Paint drawing of things I thought of after our first competition.
In order to replicate the versatility of claws, intakes should be able to pick things up in several directions. And to beat claws in over-the-fence action, catapults should be able to launch in all directions, but that’s not really possible without some truly innovative design, so I figured forward and backwards would be enough.

The part I dislike most about catapults is that they break almost everything on the robot. Basically, the only thing we didn’t replace on our launcher at our first competition were the motors running it.

I’ll just add that we haven’t done any of these things. We won’t be launching our next competition.

So you’re switching to a claw now?

An adjustable angle on the fork would also enable multiply firing distances by giving objects more height rather that distance.

What launching mechanism were you using? We used a choo-choo and the only thing we had to do to it was tighten a couple screws once and a while.

What’s the advantage of a choo-choo over a slipgear?

I’ve never tried a slip-gear, but I know one advantage of the choo-choo is that it doesn’t have any rotational force pulling on it when its down, so no motor power is needed to hold it in place. It can be difficult to prevent it from bending upwards though.

Ohh ok. How does one go about building one?

This video was usefull for me: Choo-Choo Mechanism Explained
But vex parts can’t really handle that kind of stress on one side like that. We doubled the system and used high strength axles which worked quite well.
This is the system we used: Yes it has 8 motors, the actual version had 6.

I just remembered that the main reason everything we had was bending and had to be replaced was that we had two separate “hammers” much like xlr8, which wreaked havoc on a lot of things. And we didn’t own any high strength 84 tooth gears at the time, so the inside of the gear cracked and had to be replaced just in case for safety (and aesthetics partially :)). An improvement we would’ve made is to connect the hammer with the arm itself. There wasn’t too much of a need for the split usage (weak and strong launch), although it’s the simplest way to adjust distances.
I don’t really remember what I was thinking when I posted what I did. Catapults, when built well, are not horrible in terms of maintenance.

Yes. Launcher is nonexistent now.