PisaBot by BlinkMaker

Last crawled date: 3 years, 1 month ago

This is (probably a world-first) one-stepper motor self-balancing robot! I named it 'PisaBot' based on the popular Leaning Tower of Pisa since the robot has to constantly move (or lean) back and forth so as 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 in order to shrink the overall design and make it as compact as possible, to further reduce the robot’s height (minus the cover) to keep the centre of gravity as low as possible.
The code and smartphone app are from JJrobots’ B-ROBOT EVO 2 and unmodified: https://github.com/jjrobots/B-ROBOT_EVO2
But the PisaBot can currently only move forwards and backwards since there is no turning mechanism. In the app, the “PRO” mode also 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 on the front and back side of the robot) goes into the rubber bumper hole so that you can use an M3 screw to hold it tightly to the motor mounting plate extension that juts out in the front and back. The selected wheels allow the motor and chassis to stay above ground as high as possible without the outer diameter rubbing against the electronics plate. You could also use some other wheels but keep the outer diameter under 90 mm.
Notice: This project is not sponsored by JJrobots. I used their shield only because i had purchased it a while back when i first started to experiment and learn about balancing robots so it was easier and faster to test my one-stepper motor robot design. But it's a good learning resource as their work is fully opensource. 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