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).
Specs:
0 motor drive
0 motor mobile goal lift
0 motor cone dropper
I am happy to answer any questions about the “passive robot”.