Robot weight requirement

There has never been a robot weight requirement


If you can fit the mass of a star in an 18” x 18” x 18” cube, go for it. That being said, you’d probably be disqualified for unsafe warping of the planet’s orbit…


Generally speaking, making your robot as light as possible while not sacrificing structural stability is the move. Trying to run a 15lb robot on 4 200rpm motors is going to be safer on the motors than running an 30lb bot with the same setup.


Famously, or infamously if you had to play against it, there was a 50-60 pound robot that competed in Gateway. It was loaded up with 0.025 tons of steel plate to give it more traction than anything else fielded that year, and made itself an Immovable Object.

Unless you’re doing some super defensive strategy, though, usually less weight winds up better after you’ve passed the point where your motors can no longer burn out from a standing start.


Jon of 2158X built an 86lb robot in Turning Point.


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I suppose if the weight of your robot damaged the field tiles it would be illegal, otherwise, as others have said, no.

Would neutron stars count as non-functional decorations?


That robot was 2W from gateway

I have all the threads about it bookmarked XD


I mean I would personally go with a black hole but it’s a good idea


I think the police might have something to say about that way before you ever get to the inspection table


Doing some quick math, the maximum weight a robot could be is 1325.5 lbs, based on a 17.5x17.5x17.5 cube built entirely from vex metal plates. Weight could be increased if you shoved axles in all the holes. But to be legal, you’d have to remove some of the steel to make room for the V5 brain and battery (required by R1 subsystem 2), and that would reduce the weight a bit.


Way too much time on your hands :slight_smile:


To be honest, I dont even think the high strength axles could hold something of that weight.


From the Tower Takeover game manual:

<R32> Middle School team robot shall weight less than the total weight of the driving team members.


I expect the EP might have an issue with a team requiring a forklift to place their robot on the field. It might damage the tiles…:wink:


Fun facts from a science class: 18" column of steel is about 6 lbs (density is 0.28 lbs/in^3).

So its ground pressure is about 6 psi.

Adult human’s average ground pressure is between 8 and 16 psi.

So no field damage, if you can get the robot there. Gotta watch your toes tho.


@TherealKate as @Connor said there is no maximum robot weight requirement spelled out by the game manual.

However, your choice of the drivetrain type and gearing will generate a number that is practical.

For example, if you have four 4" omni wheels on your base directly driven by 200 rpm V5 motors they could generate about 18 lbf of the force, which is about the same as 19.5 lbf of the ground friction for 15 lb robot on those 4" omnis.

Lighter robot will not be able to take advantage of all the pushing force those motor provide and heavier robots will just waste more power on friction without giving you more pushing force at 200 rpm direct drive.

Most of the VRC robots naturally end up in the range of 13-17 lbs with a few exceptions lighter or heavier. (I didn’t do formal study, I just keep asking people what is the wight of their robot all the time :slight_smile:)

If anyone build such a robot they need to consider changing their drivetrain gearing or number of drive motors such that pushing force better matches the tractive friction and friction losses in the drivetrain.


Let’s not forget, there is no requirement that the robot move :). NbN was an example where you could significantly contribute to scoring without wheels…


The only weight constraint I can think of is R25:

This indicates that the team needs to be able to transport the robot to the field and place it on the field without requiring an adult to lift it (since the definition of Team does not include adults).

In general, if the students in a team cannot pick up their robot, it is probably too heavy. All other weight constraints should be related to drivetrain or structure…