Best mechanism for this season? Flywheel, Catapult, or Puncher

Okay, so as of now im contemplating as to what mechanism would be best for this season. I’ve thought about the pros and con of each but can’t decide which would work the best for this year. Any feed back from any team would be valuable and deeply appreciated.

Thanks in advance, Team Shadow


A lot of teams have already posted videos on YouTube of their robots this season (or, a RI3D video, so some prototypes). I would recommend looking at some videos and compare and contrast some of these and how they work. They should spark a lot of inspiration for your team (and I can confirm because it’s inspired my robot design brainstorming).
Good luck this season!


Flywheel would probably be the best option because you can shoot non-stop and not have a reload time. Right now we are building a flywheel kinda like 79298C’s. However catapults and punchers are also very viable. I’ve seen a lot in the recent reveals. 24118E and 938X have catapults, and the 21S, 334B, 1469A collab had a puncher. But it all really depends on what your goal is. If you only want to shoot for matchloading, flywheel is probably best option. If you want more accurate shooting into the goals, a catpult or a puncher would be great.


It seems to be a confidence problem on your team. You might want to use different techniques for making decisions, it could be a pro - con table, or a decision matrix that weighs different factors to pick a pathway for your team to pursue. That is what engineering is all about!

Asking the forum for a particular pathway for your team really is not great.

Here is a better question “Hi, we are currently considering flywheel, catapult, or puncher - all which are within our expertise, available materials, and match for our season game strategy. We would love to hear about other approaches you are considering and drawbacks you have identified”

Back to your original post - what are you trying to accomplish with these implementations? What experience do you have? What materials available? The way this post is phrases really limits ideas and feedback…


Adding on to lacsap’s post, some things you will want to consider are these:
Shooting speed for match loads
Lighter weight will help elevation
Power, accuracy and roll/spin for shooting in the goal
Compatibility with the rest of the robot.
Personally, I think that punchers are the best because they:
Have a decently fast reload time
Are consistent enough to score in the goal
Are simple to build
Only use one motor, could be ratcheted to the intake
You may also want to consider that a human realistically can’t load faster than around .5 seconds. Maybe you could push it to .3 with training. This means that the essentially unlimited flywheel cycle time wont give a big advantage. Flywheels will also require an indexer, which is why I do not think they will be very good.


All shooting mechanisms have a “reload” time.
And I have not seen a flywheel that will allow you to shoot non-stop.

Flywheels work by transferring the flywheel’s momentum to the balls. And the flywheel will slow down every time the momentum is transferred. It will take time (however short it may be) for the flywheel to get back up to speed again.


What do you mean here? You can’t possess 2 Triballs, so there is some time, and it is harder to Match Load legally (see Q&A)

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I see everyone in this thread has given great answers, but have you guys considered any strategies that to not include throwing triballs over the barrier? I would recommend imagining what the robots in the dome might be like this season. Early season tournaments have shown teams that it is very easy to greatly impede a cata/flywheel/puncher by playing simple defense or just deploying a small shield. While I know teams will find a way around this, I recommend that you think a little deeper than just “what method of throwing gets best reload time”. Hope this helps!


We are a first time competing team and have no idea what we are doing I was wondering were we can get some easy info and starting point. great place to start - in particular

I would read post on VEXforum, get to know the rules really well, and if you need unofficial clarifications, ask here, or if official ones, ask the official Q&A…

While navigating the whole spectrum, there are many great teams offering their experiences, in particular a shoutout to 515R for their engineering documentation (look up on Youtube)

Do connect with your regional RECF Team Engagement Manager, and they may be able to put you in touch with teams local to your area.

Best of luck this season!


Vex forums is one great way, so welcome to the forums! Other ways include watching lots of vex robotics competitions, robot reveals, and robot explanations on YouTube. I would also recommend reading through the official game manual once or twice. If you have other questions, feel welcome to ask!

For game information, your team will want to watch the game video and read the game manual. For ideas, you can find lots on YouTube.

This was a reply I had to a different post but it might help:
In that case, some pointers I have for you are to:

  1. Learn more about the field and the game (Game Analysis)
  2. Study the Game Manual
  3. Maybe watch some previous tournaments/scrimmages so you can get an idea of what the actual competition looks like
  4. Learn more about the VEX parts/conduct research on them
  5. Learn more about improving your performance
  6. Work on Skills
  7. Review good examples of notebooks to get an idea, and actually do the notebook

After you do all of this, then ask your questions about what you want to know more about. Trust me, this will help you greatly for your season. Good luck with this season!

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Wallbot !!!
(20 char)


The top teams will find ways past this. For example, a catapult that can shoot such that it can clear a wallbot that is 20" (or some other arbitrary measurement) high. If you think about it, you HAVE TO go over or under the barrier, and the thing that will be variable is how that is done. There is also the factor that a wallbot stopping you from getting Triballs is a wallbot that is not scoring. Any cross-court shots are unlikely, so it might be the best strategy to just wait and play a game of chicken. Ultimately, I feel that, like TiP, once a team gains a slight advantage, like in Autonomous, it will be hard to overturn. Ultimately though, it is important to compensate for this. I don’t care that mechanism X can shoot 22 Triballs in 3 seconds if it is easy to intercept. It is easy to forget that driver control is 1:45. These are all design considerations that have to be evaluated in your notebook.


Why will a robot have to go over the barrier?

I half agree with this. As you mentioned earlier, a robot that is blocking the opponent from matchloading won’t be able to score. For this reason, we can assume that one robot will be shooting Triballs to the other side while the other robot will push them into the goal. Let’s say Team 123A&123B gets a 3 Triball advantage over 456A&456B. However, 456B has a faster shooting mechanism than 123A, so it gets all 22 Triballs over the barrier in the time that 456B only gets 18. Now the 456 alliance has a 1 Triball advantage. However, this advantage should increase, because 456B will essentially throw back every Triball that 123A shoots, and every few seconds it’ll get an extra Triball in. Thus, it is important to:

  1. Have a fast cycle time
    but even more importantly:
  2. Be able to navigate the field quickly.

That is why I feel like rather than rapidfiring 20 triballs, the defensive alliance partner will just have to look for openings in which to toss a couple over. Navigation and agility is soooo key. I would even argue that I might rather have a 6M drivetrain than a speedy flywheel.


IMO 6M drivetrain is necessary because there will likely be heavy defense on the goals. If you can’t push the opponent so that they can’t score triballs then it will be much worse than a slightly slower cycle time. This is one of the many reasons I think flywheel is completely unviable. We will see the meta develop though, so we can only guess for now.


Sorry for the ambiguity, I meant that the Triball has to go over the barrier. I was half asleep when writing that.
As for the second part, I agree with that assessment when there is no defence going on. What I would propose is to have two different types of shooting, one that is quick for these scenarios (quantity) and one for when there is heavy defence. Ultimately, there have been very few competitions so far, so I think we need to wait until a big competition like MoA before theorising about how games will play, because we have little to go off of.


Don’t forget human nature… What driver/shooter will watch the triball in the air, instead of reloading without caring? Catapult would always be airborne longer than puncher.
Seems teaming IS the answer, with a strong bot pusher… One clears the opponent from the goal. Two is Shooter, always designed for accuracy of punch delivery (and climbing). Also add an “assembly” for defensive blocking of goals while shooting.
Finally, I suspect several adults on this chain… Remember, brainstorm the FULL list of ideas, and the TEAM rules out all but one… Probably best evaluation by “scoring” (with probability) how many total points you could achieve with each… Remember, you need to LIFT a flywheel, which could cost you 20 points!