Low Robot vs High Robot for Infinite Recharge Challenge


Clearly I am stuck in the past


An arguably key one is that in 2016 being able to go under the low bar made it easier to gain an RP during the match. In 2020, its just a passable area with a safe zone.


I think the biggest challenge that will come with building a low-robot will be running out of space to store 5 balls. Building to be under that height lowers your max-volume by 38% (28in height vs. 45in height). I think this will make the challenge of storing 5 7in diameter balls at once in addition to a feeder and a shooter into the space much more challenging.

Aside from this however, I think all teams are already going to have a mechanism which lifts above their standard height for the purpose of climbing. Incorporating the manipulator for the control pizza onto this would probably be trivial.

Also I definitely disagree that only 1 robot on an alliance can benefit from trench cycles. If the alliance incorporated the simple rule of only use it driving towards the goal, you’re still getting free passage on half the trips, so 2 or 3 robots doing this will benefit as much or more than only 1 robot doing it.

The only thing a defender has to do in this game is camp the rendezvous point and/or the area between the opponent trench and the target zone. The highest scoring matches will be from teams which are able to dart from their loading zone to their trench and score all 5 balls in the high goals.

Of course, the even higher scoring matches will be from tall robots who are able to score all 5 balls from the other end of the trench on their own side across the entire field, ultimate ascent style.


Interesting I did this exact same poll here and it came out 50/50. Scary results IMO.

I think a lot of teams are overestimating themselves if they think they are going to hold 5 cells, have a high shooter, and climb all in a robot less than 28". Not saying it can’t be done, but by 50% of CD population…no


I agree. The feel and flow of the game is likely to be more like 2012, but from an engineering standpoint, 2016 - this is certainly the greatest active robot interaction with field elements since 2016. Looking farther back, there was little between 2008 and 2015, but four of the games from 2001 to 2007 had goals that moved.

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I think the last time we had a low vs. high decision like this was stronghold, I have been thinking about the robots from that year and considering the challenges that a low robot posed which a high robot didn’t.

Some pros of low robots regardless of the game are the low center of gravity and relatively high density but also have cons like not having room to package mechanisms or requiring more complex mechanisms.

There were plenty of highly successful “tall bots” in 2016.

My advice after a full night of sleep is to look at the off-season convergence of the robots for the 2017 game. The ultimate robots were tiny, almost FTC sized.

Like 2020, 2017 was a cycling game and smaller lighter robots are faster by default. The same wattage will accelerate a 100 pound robot significantly faster than a 150 pound robot. An 80" frame perimeter will allow a robot to navigate through a tight field quicker than a robot with a 120" frame perimeter. Finally a 100 pound robot will climb faster and more reliably.

Look at the minimum size/weight you can get away with to hold whatever you need for an intake, shooter, power cell storage, control panel manipulator, and climber.

If you make it light enough, you can have a high terminal speed without needing a gearbox which just makes it lighter.

(This advice does not apply to anyone who is now saying "But what if I want to get into a pushing match!!! They don’t care about cycle time anyway.)

I think that with the proper wheels/suspension, you should be able to just power over the small terrain inside the switch mechanism, driver skill and center of gravity permitting.

With all the elevator development the past two seasons, I really want to see elevators used for more than a simple hang this year. An elevator is not needed to hang, and it’s a really complex way to perform an easy task.

But…what about having most of your mechanism on an elevator, so you go from short to tall robot? Then you can drive under the pizza, and shoot from just under 45", and easily spin the pizza, too. The elevator could also then go up a bit more and be used for the hang.

I have no plans to suggest this to our team, since our elevator last year was rather flaky. But I know there are quite a few teams who could pull this off, and I’d sure like to see it in action.


But that means your elevator (aka entire robot height) would need to be under 28"? Also were you suggesting combining the climber mechanism, shooter (low goal and/or high goal), and CP mechanism all in one elevator? It just seems to me trying to pack so much in so less space (plus storing a max of 5 power cells) seems like a bit too much. I also think it should be taken into consideration by how much this will influence/increase the weight of the robot will affect the speed, which directly influences cycle time.

Additionally, are there any specific examples like this (using an elevator for multiple tasks/having most your mechanisms on it) from the past? I just want to be able to visualize. Thanks!

Personally, I’m thinking that rotating arm(s) will work better apart from a climbing winch, but if you are thinking elevator: Given the difference in power needed for the “short to tall” vs the climb, it might make sense to put a low-speed-high-force elevator (climber) on top of a faster (get tall) elevator.

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I mentioned the idea of using the elevator for the hang as well as the other mechanisms, because when I searched for the word “elevator” in use here on cd in the past two days, that’s where it showed up.

My take on High vs Low


  • Better trajectory to high goal
  • Harder to defend against
  • More storage for balls so less jams
  • Easier to do Color Wheel (aka Wheel of Fortune
  • Easier to store climber


  • Go under trench slightly reducing cycle time
  • More compact and lower CG


  • Bigger and Heavier
  • Can’t go under trench


  • Easily blockable
  • Less area to work with
  • Harder to package mechanisms

By no means is this true. Keep in mind, nobody can get taller in the shooting areas.

A robot shooting from a 20-24 inch release point just needs the ball to be 38 or more inches in the air by the time it leaves the volume of the robot. A robot shooter in the “back” of the robot buys it plenty of distance to get this height.

This isn’t 2016. Don’t box yourself into a corner where you can’t move around the field freely because you were afraid of blocking that you could easily have designed around.


Actually, about five or six inches before that (allowing 6-7" for two pair of bumpers). I don’t recall any rules which prohibit the opposing robot from reaching into your frame perimeter above your robot volume. If it’s above, there won’t be any contact (much less damaging or impairing contact) so G25 does not apply.

If you are shooting with an opposing robot, bumper to bumper, directly in front of you, that’s your problem. Multiple zones on the field exist where such an interaction is an automatic penalty - perhaps shoot near those areas.


And low robots have a longer cycle time than high robots.



The high bot can shoot from half court. I don’t think your low bot will be able to…