Champaign-Urbana Community Fab Lab
Illinois Informatics and School of Information Sciences
Champaign-Urbana Community Fab Lab

Pom Pom bot but by air.

Description.

For this assignment we are to use arduino and some 9g servo motors to creating a robot of some kind that can move at least an inch. Over the course of the assignment we are to: design a concept, design a prototype, make a 2nd prototype, and make a final bot that moves the inch. For the concept we are to put our ideas out on paper in a sketch or in words. For the prototypes, we are to describe what challenges we face and how we plan to combat these challenges. Same goes for the 2nd prototype except we have to talk about what improvements we made from the first prototype. I went about this project a little bit differently, my robot traveled by air. Air as in it traveled along two balance beams that were held up by two tables (you’ll see in the video). This project was a bit stressful, I’ll speak more about that in the reflection. 

 

Initial Design.

The initial design for was air travel robot was to have a single skewer hold the servo in the air and move each end a couple degrees at a time. Basically my robot was going to look like have of the thing constructed below.

 

My robot would use: pipe cleaners, skewer, pom poms, Popsicle sticks, servo, and a bent paperclip. Pipe cleaners were used to hold everything in place. Skewer was used to hold the servo in the air. Pom poms would act as anchor points, these would ideally move down the balance beams. Popsicle sticks would be used to construct the beams it would balance on. Servo for movement. Finally, the bent paperclip would be weaved through the servo fin to hold the pipe cleaner skewer in place when moving. 

 

Initial prototype.

This video shows my first prototype and the biggest issue that I would spend many hours trying to solve. That issue being the fact that the skewer and servo motor are separate entities. Since these two are independent from each other they will not move in unison. Either the servo moves or the skewer moves. If I were to pinch the servo motor with my hands the robot would travel that inch no problem. So, I started to think how I can unify these two parts. I will not change the base of my design but, I could add a couple things to the servo to hold it all together. I thought of using rubber bands and an extra pipe cleaner to hold everything more tightly together.  

2nd prototype

Here is what the 2nd version looked like. The new pink pipe cleaner is wrapped around the center of the skewer and motor. This pipe cleaner actually did a nice job of holding it all together! Next I would take two rubber band and quadruple bind both side of the skewer. The servo motor has these little notches on the side that made for great rubber band sockets. Overall the 2nd prototype was far more secure that the first one. 

I don’t have footage of the testing but the same thing happened, it didn’t move. The servo was still acting as an independent body. This is where I discovered that force was not my solution so I began to look elsewhere (not force) for my final design. 

I began to think back to my initial design, about why it didn’t work. I said that, if the servo didn’t move the skewer would, thus I should try to find a way to hold the servo still. I tried to work against the separate bodies when I should have been working with them. Once I thought of this, I finished the project in the next 20 min. 

Final Bot.

https://www.dropbox.com/s/90vp1q8sacqmz94/20190408_181624.mp4?dl=0

Side note: I will never get over hearing myself in recordings, yuck.

So, here is the final design! Like is said the problem was not the force but of holding only the servo in place. The way I did this was by putting two large Popsicle sticks right next to the motor. These Popsicle sticks would be held in place by the force of two tables pushing on them. These forcefully held Popsicle sticks would act as walls for the servo to stay in place. In the video, one of the Popsicle sticks fell. This reduced my robots movement speed to a shimmy but still got the job done. Instead of being held still the whole time, it would only stay still for a small about of time, thus the shimmy.In this assignment (I’d imagine) one would have three key components: Means of travel, motor, and a core. For the bulk of this assignment I only had the motor and core. Not until I found my means of travel, did I complete this assignment. These side sticks seem odd, but think of it like they are feet. They are a means to move not directly connect to the main body. Would a robot with just toothpick legs be able to move? That is how I justify this addition. 

Reflection

Once again, I made this projects leagues harder then it really needed to be. Traveling by air proved to be a bigger challenge than I initially thought. Physics and stubbornness were my biggest issues for this project.

The issue of physics was the initial problem that made this assignment harder than it needed to be. To start off, the wacky physics I had to deal with we solely because my robot was in the air. Where most would have a robot that would exude a force back on the table, keeping everything together, my robot exudes a force downward, pulling on the sticks. I do not have the physics expertise to competently explain this, but this pulling down force seems to have made the two bodies separate. Moving on, stubbornness forces me to not give up fast enough to pursue alternative solutions. I usually get so fixated on a route to the point where I end up forcing it to work. This is more of just a personality trait that gets in the way more than a specific assignment issue.  Overall, stubbornness and ignorance do what they do and delay progress. 

As you have noticed my robot only had one motor and not the required two. This was due to be just assuming details instead of actually reading them. I figured we just had to make a robot move, and that the two motor robot was only for class. Since learning this error, I have thought about about a couple designs that I felt I should throw in, for what it’s worth. first design would look something like this -> \_🔲|🔲_/ The boxes are the servo motors and the lines are the Popsicle sticks. This robot would employ a climbing movement along the Popsicle sticks. I would have to put notches on the outer side of the popsicle sticks and something on the ends of the arms so that the arms would have something to hook onto. Almost a sliding lock. The other model would be like the initial two motor design at the top of the post. The design would be a cross that would spin continually on top of two layers of Popsicle sticks. Once one half of the wheel crossed into the middle (where it would fall) the other half would be holding it up. Ideally, in a perfect world, this design would act like a wheel as it spins down the lines of sticks. 

 

 

 

 

 

 

 

 

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