It is alloweda 3600 tpm motor cheat on Over under?

I recently found a video that shows how to cheat a motor and make it 3600 rpm. And i’m asking if this motor is allowed on vex Over Under competition.

Here is the follow video:

I would like to know. Thanks!

Please read the Game Manual about what is permitted in terms of modification to VEX electronics and requirements for motors.

It is pretty clear your answer is there.


Welcome to the forums.

For any question about the legality of something, we must turn to the game manual (or the Official Q&A). As you read the game manual ( ), keep in mind that the game manual tells you things that you must do, and things that you are prohibited from doing. It can’t tell you everything you might do, so if the game manual does not prohibit an action, then it is generally legal. The game manual does not generally discuss any particular game strategy or mechanisms you might use.

In regards to your question, it was not “cheating” in the previous season, however, for this season, you need to review the revised rule R14 (c) in the game manual. Feel free to post again after you have reviewed the game manual if you have additional questions about what is allowed.


The game manual says that this is illegal.
You are only allowed to use the cartridges vex sells.


Legality aside… I can’t see how 3600 rpm will be useful for this season.


You mean no one will try to convert the energy of spun up flywheel into elevating of the robot to the top after the final bell rings?

I am sure your short matter-of-factly comment was carefully crafted to achieve the counterintuitive effect of stimulating creative thinking among the readers to come up with crazy ideas to use 3600 in this game.

It certainly got me thinking that way.



Flywheel meta. (Faster then catapult or puncher at launching triballs)


The issue with flywheels is that they are dead after you shoot all of your match loads over. A cata can double as a climber very easily as seen in Purdue’s RI3D. On top of that, you will have to make an indexing mechanism because human players are not allowed to push the triball into the flywheel (Please correct me if I’m wrong there).

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You’re only wrong if the bot is contacting the loading station’s bar

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You got me there - I should have thought of this “helicopter” approach for elevation. Back to drawing board for me…


Refer to R14 of the game manual.

Specifically, C1, and D

Just build an intake. Marc is a prime example.

It depends on how fast you want to shoot, but I imagine you’d want atleast 11w on the catapult so it could be drawn back and fired quickly.

And the MARC bot being built in under 24 hours meant that we didn’t have time to tune it that well / try out different gearing ratios that could potentially work better with less motors. As a result the flywheel is way overpowered to brute force it’s way through friction / imperfect tuning and you can see it shooting some balls out of the field in the video.
Without the very short time constraint to design, build, and tune a whole bot that we had I think a good flywheel could be made with only 11w and be competitive with a catapult of the same power.


That is very true, never considered that. Though the one downside is the space a flywheel may possibly need. A catapult also requires some - but possibly less space.
Also, if a robot is in position for match loads from a human player - is the human player allowed to feed the tri-balls through?