PisaBot

thingiverse

This is a world-first, one-stepper motor self-balancing robot! I named it 'PisaBot' after the famous Leaning Tower of Pisa because the robot has to constantly move back and forth to keep its balance. I designed the chassis in Autodesk Inventor (except for the Pisa Tower cover which I edited in Tinkercad from utechlab's design: https://www.thingiverse.com/thing:1129396) and 3D printed all the parts. This is the final version after more than a dozen prototypes to make it as compact as possible, reduce its height, and keep the center of gravity low. The code and smartphone app are from JJrobots' B-ROBOT EVO 2 and unmodified: https://github.com/jjrobots/B-ROBOT_EVO2. However, the PisaBot can only move forward and backward since there is no turning mechanism. In the app, the "PRO" mode works to give more power when controlling the robot. Here is a video of my prototype: https://youtu.be/m9uo7Uep0QY List of parts used: 1 x Double Shaft Stepper Motor 42mm Nema 17 1.7A 17HS4401B https://www.aliexpress.com/item/Double-Shaft-Stepper-Motors-42mm-Motors-Nema-17-Motor-1-7A-17HS4401B/32849735638.html 2 x LiitoKala 18650 3400mAh rechargeable battery 3.7V Li-ion 1 x 18650 battery case with 2 slots https://www.aliexpress.com/item/Black-Plastic-1x-2x-3x-4x-18650-Battery-Storage-Box-Case-1-2-3-4-Slot/32847696147.html 2 x Hex coupling, 30 mm length, 5 mm hole diameter. 2 x RC wheels 1/10 Off Road Hex 12mm. Tires Outside Diameter: 85mm and Rim Width: 34mm. 2 x Rubber Bumpers Pads https://www.aliexpress.com/item/Practical-10Pcs-21mm-x-12mm-Black-Conical-Recessed-Rubber-Feet-Bumpers-Pads/32702629332.html 1 x JJrobots Electronic Brain Shield https://www.jjrobots.com/product/b-robot-electronic-brain-shield/ 1 x MPU-6050 (gyroscope and accelerometer) 2 x A4988 stepper motor drivers 1 x Arduino Leonardo M3 stainless steel button head screws The washer for each bumper goes into the rubber bumper hole so that you can use an M3 screw to hold it tightly to the motor mounting plate extension. The selected wheels allow the motor and chassis to stay above ground as high as possible without rubbing against the electronics plate. You could also use other wheels but keep the outer diameter under 90 mm. Notice: This project is not sponsored by JJrobots. I used their shield because I had purchased it a while back when I first started experimenting with balancing robots, so it was easier and faster to test my one-stepper motor robot design. However, it's a good learning resource as their work is fully open-source. You could also try making your own compatible shield with MPU-6050 and ESP8266. The shield schematic is available at: https://github.com/jjrobots/B-ROBOT_EVO2/tree/master/Hardware/electronics