The 3D printed parts are a frame and wheels for a balancing robot. This frame is designed for an Arduino Uno and NEMA 17 Stepper Motors. I included a parts list for the components I am using in my project.

I made a motor control sheild for two DRV8825 Stepper Motor drivers. This Thing can be found here: https://www.thingiverse.com/thing:2830191

This Thing is not ment to be a balancing robot instructional tutoral, but is provided as is for anyone looking for a test bed for a balancing robot. There are several very good tutorials with detailed construction and sketches out on the internet for some tried and tested balencers. If your like me, and want to figure it out your own, feel free to use or modify these files. I will include the Fusion 360 files of the design if you wish to make modifications to this design.

This is my second 3D printed version of a balencer body frame so I have incorperated some features in this version. I have room for one more shield on the Arduino stack for future radio control. The shelfs are removable for access to all components and easy motor removal. The distance to the centers of the wheels is aproximately 2X the diameter of the wheels. FYI, at the time of posting, this design will balance.

MP3DP

No

No

.2 mm

30%

Rotate parts to print with the largest flat side down. No supports will be needed.

3D Printed Parts List:
2 - Frame Side (1)_rev
1 – Frame Bottom
1 – Shelf
1 – Frame Top
2 - Wheel

2 – Stepping Motor NEMA 17 17HS16-2004S1 (https://www.omc-stepperonline.com/)
1- BNO055 IMU Breakout (https://www.adafruit.com/product/2472)
1 – Arduino UNO
1 – Motor Control – Info & Instructions (https://www.thingiverse.com/thing:2830191)
1- Mini Breadboard - (https://www.adafruit.com/product/65)
8 – Flat Head w/tapered countersink, Machine Screws & hex nuts - #8-32 x 5/8"
4 – M3 12mm Screws
4 – M3 8mm Screws
2 – M4 Set Screw
1 – Used Bicycle Innertube
Misc Wires, battery packs, mounting screw for Uno, velcro straps for batteries.

3D print parts per 3D Printed Parts List above.

Test fit all parts and make adjustments if necessary.

Attached stepper motors to sides with 2 M3 8mm screws per side only in the top two holes.

Attach bottom shelf to the frame sides. The dimples on the bottom shelf go through the holes on the bottom of the frame sides. Secure the bottom shelf to the frame sides with 2 M3 12mm screws in the bottom two holes of the motor.

Attach the Mini Breadboard on the center shelf with the adhesive on the bottom of the breadboard. Insert the IMU in the center of the breadboard.

Attach the center shelf with 4 Flat Head Machine Screws and secure with hex nuts below.

Attach the Arduino with 4 small screws in the holes provided. Affix the motor control shield to the Arduino. Note: Do not overtighten Arduino mounting screws as there are no supports directly below mounting holes. Use double nuts to act as a lock nut.

Run wires from stepper motors and IMU through the holes in the center self and terminate the wiring.

Attach top shelf to the frame sides with 4 Flat Head Machine Screws and secure with hex nuts below.

Cut two strips of used bicycle tube to create two 1/2 inch wide rubber bands. Turn these inside out if they are smoother on the inside surface. Wide rubber bands can be used. Pre Stretch the bands then stretch the bands over the wheels to create a rubber wheel surface.

Press on the wheels to the motor shafts. Test wheels to assure wheels do not turn on the shaft. If the wheels are not sung, remove the wheel and drill a 1/8" hole in the sleeve above the flat section of the inner motor shaft hole. Screw in a M4 set screw and tighten until the wheel is secured to the shaft.

Velcro Batteries to the top shelf.

It is important that the wheels fit snugly on the motor shafts. Each step of the motor needs to rotate the wheel, so any slippage will degrade the performance of your balancer. Due to differences in printers and settings, your results may be different than my results. When I printed my wheels, one was too tight requiring post printing filing and scraping inside the shaft hole that wasn't easy. The second wheel was too large requiring a layer of scotch tape and a set screw. After 5 test prints, I wasn't able to find the perfect fit. I provided the larger hole version in the STL files since this was the easiest solution. In the Fusion 360 design file, there is a test wheel along with a test sleave if you wish to have a go at finding that Cinderella fit.