A self-balancing robot with a single stepper motor. This is a novelty (according to my research) for a self-balancing robot which uses a single stepper motor with dual shaft. Its name is a nod to the popular Leaning Tower of Pisa in Italy.
I designed the chassis in Autodesk Inventor Pro (except for the Pisa Tower cover which i modified from utechlab in Tinkercad) and then 3D printed all the parts. This is the final version after more than a dozen prototypes with the objective to shrink the overall design and especially reduce the robot’s height (minus the cover) to keep the centre of gravity as low as possible.
The Arduino code together with the controller smartphone app are from JJrobots’ B-ROBOT EVO 2 and both are completely unmodified. The “PRO” mode also works to give more power.
Delimitation:
The PisaBot can only move forwards and backwards since there is no turning mechanism. I plan to implement it when i have some free time and then i will update the repository with the design changes.
List of parts used:
- 1 x Double Shaft Stepper Motor 42mm Nema 17 1.7A 17HS4401B
- 2 x LiitoKala 18650 3400mAh rechargeable battery 3.7V Li-ion
- 1 x 18650 battery case with 2 slots
- 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
- 1 x JJrobots 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
Download the chassis parts in STL format to 3D print:
https://www.thingiverse.com/thing:3045793
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.