Motorless Robot reveal!

A couple of weeks ago, I challenged myself to see just how much I could do with building a robot that uses 0 motors, and 0 pneumatics. This was a fun project, but it was very challenging.

Here is the motorless robot!
This video is of the robot doing it’s “autonomous”:

And here is a video of me explaining how it works:

From now on when I refer to motorless mechanisms, I mean motorless and pneumatic-less mechanisms.
First, several things I learned from this project:
-Motorless mechanisms are only useful for one-time actuations (this should be obvious)
-It takes a LOT of elastics to drive a robot
-Rubber bands/elastics are much better than gravity for powering most motorless mechanisms
-Motorless mechanisms aren’t very consistent without a large amount of fine-tuning (this is what took the majority of my time)
-If you want to have a sequence of motorless mechanisms, create “triggers” that the previous mechanism will trigger to start the next sequence/mechanism
-More complicated motorless mechanisms take a very long time to set up before each use; if you use a motorless mechanism on your robot make sure you have ample time to set it up before each match.

Due to running out of time before worlds, I decided to upload the video of this robot before tuning was complete. As a result, the robot doesn’t complete the autonomous in the video.

The robot that I ended up with uses lots of rubber bands, but it can (kind of) score a mobile goal in the 5 point zone with the preload on it in “autonomous”. A couple things:
-I realize it is not fully autonomous. I have to hold it still and let go when I want to start the “autonomous”
-I realize the robot is not competition legal. My goal was not to build a competition legal robot, the robot is a little too tall and much too long. I could have added a motor/pneumatic brake to make it fully autonomous, and I also could have made it inside size requirements, but that was not the point of this project.
-I realize that in the video, the “autonomous” doesn’t completely work. I wanted to get this thing finished before worlds, and it ended up taking more time than expected. Rather than spending more time on getting a video of it working perfectly, I opted to take a video of it not working, just to show the concepts I used (and the first part of the “autonomous” still works too).
-The robot I built is NOT consistent: Before you go getting the idea to make a motorless robot for an actual competition (for the memes of course), keep in mind that with several motorless mechanisms, each relying on the previous mechanism to execute perfectly, there is a lot of room for error to accumulate. It takes a LARGE amount of time spent tuning to get rid of this inconsistency with this many motorless mechanisms, which is why mine isn’t consistent as I ran out of time.
TL;DR If you’re wondering why I built this robot, it was to see how far motorless mechanisms could go. I know the robot doesn’t work super well, but it is a good demonstration of the limits of motorless mechanisms. With more time, it could have worked much better. I think motorless mechanisms will be useful in the coming years with the motor limit decreasing to 8, and especially if the game has any one-time actions (think high-hanging).
0 motor drive
0 motor mobile goal lift
0 motor cone dropper
I am happy to answer any questions about the “passive robot”.




Antichamber, im honestly astounded it works as well as it does, make it score that in the 20 point zone, and you have a legitmate robot on your hands!

Cool! I’m impressed. You may have established a new off-season challenge!


@9065_Parker You know that’s not antichamber, right?

This is interesting…

I saw this and expected another troll thread.
I was greatly impressed by this and far from disappointing.

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It’s to bad that it is not legal to use due to not having an electronics system.

Well done. This is a great exercise in understanding potential energy, elastics and hookes law, as well as mechanism design. I would definitely recommend others to try the same challenge, because it challenges you to come up with passive mechanisms that you can possibly use in future designs. Team 8000 had a highly passive system in last year’s game and did quite well. A passive subsystem allows your robot to do more without sacrificing motors, which will be even more necessary for next years 8 motor limit on V5.

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Is it confirmed that V5 users only get 8 motors. There was a lot of talk but I haven’t heard anything official yet.

So Paul guessed that the GDC would decide to allow 8 v5 motors. The ruling would be part of the new game and he did not want to put words in the GDC’s mouth.

This is really cool.

Thanks guys! I suspect a motorless robot will be much harder for the new game though…

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Very cool. I’m impressed.

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Yes, this is fabulous!

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Innovation that excites


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