Project: Rumble Bot Legs and Locomotion

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I have designed a project to explore the best legs for locomotion. Brush bots are an inspiration for this project, along with an article in Make Magazine Vol 52 - Rumblebots Raceway by Douglas Stith. In fact, these bots should be compatible with his raceway and power source, instead of using a rumble motor like I did in the video.https://youtu.be/W89t2H4k3gQ Print Settings Printer: Generic prusa i3 style Rafts: No Supports: No Resolution: 0.2mm Infill: 100% Notes: I had to use TPE to get the bots to run around with the rumble motor on top. The PLA bots might work if you are using a rumbling track. I had some move, some not move, besides the spirit of the project is to experiment and figure it out. How I Designed This I came up with a bot size, sketched the body and extruded it. Then I rotated up the plane and sketched 1 leg and extruded as a new body. Finally, I made an array to replicate the leg 5 more times. I picked 6 legs to be like an insect, you can pick anything for yours. Fusion 360 - Showing bot body with 1 leg extruded and my plan for the other 5 legs. Overview and Background Brush bots! I have built brushbots with children for years, they love them! I have thought for a while, what if you could design your own legs? What type of legs are best? Well, I have not figured it out yet. Locomotion is the idea we are trying to grasp with this project. How do you move from one place to another. How do these bots do it without having legs that move like we normally think of legs? This is a relatively low documentation area of engineering. Which is a great place for experimenting! Lesson Plan and Activity Step 1 - Background Knowledge Pre work: figure out a track and whether you intend to use motors or track vibration. Print a bot to use as a visual aid. Discuss locomotion. Discuss vibration. Define bot size parameters (to fit on the track) Have students do a creative thinking sketch on a bot idea with no joints, but can utilize vibration to move. **Note: Consider not explaining too much about the way the legs work as to not hamper creativity in design. Step 2 - Design / Build Have students design their bot creation in modeling software. Have students 3D print their design. Optional: Let students use non-3D printed legs if they have proper static connections. Assemble bots, if assembly is required. Step 3 - Practical Testing Hold a bot race or time trial ** Remember to race bots fairly in both lanes if you have a 2 lane track. Have students observe what happens and take some notes about each heat. Step 4 - Review Hold a class discussion about what leg design worked best. Why do those legs work the best? Would there be a way to improve the design further? What applications could this knowledge be useful for? Tips & Tricks TPE (thermoplastic elastomer) worked best for me when using an onboard rumble motor Extruding the circle leg along a path is how I was able to make hooked legs. That is the method I used for all the legs. A couple fridge pack boxes cut down carefully and taped together could be all you need for a track. With the addition of a rumble creator. Materials Needed Accessories The following materials and items can be helpful with this project. Optional - Motor Optional - Battery Optional - Vibrating track instead of motor and battery above (see references) Optional - Tape Optional - Motor holder Track measuring devices stop watch for time trials Skills Learned locomotion design vibration Rubric and Assessment What is locomotion? How does vibration create kinetic movement? What designs work better why? What factors tend to work against the designs? References Make Magazine Volume 52 page 84-85 http://makezine.com/go/rumblebot-races http://makezine.com/go/rumblebots-explainer https://en.wikipedia.org/wiki/Robot_locomotion https://en.wikipedia.org/wiki/Vibration