A 100% recycled mobile robotics platform, built (almost) entirely from an Ender 3 and some printed parts.
I was sitting around thinking about how I could get started in robotics, and how to do it as cheaply as possible. My poor old Ender 3 V2 in the corner stared at me longingly, looking for a purpose in life since I had bought a Creality K1C.
Thus, Steppy was born.
I'm not the best at writing readme files, especially when the project is still at its inception, but I'll share my progress here as I develop it, and hopefully other makers will build their own, re-using the obligatory Ender 3 in a closet that all makers end up with eventually.
- Reuse as many components as possible from the Ender 3 V2—like, seriously everything.
- Create a functional robot car platform that can be used for other projects, not something that gets in the way of its actual purpose.
- Demonstrate creative hardware repurposing.
- Printed Parts (you either have a working Ender 3, or another 3D printer)
- X, Y, Z, and E stepper motors for 4 wheel drive
- GT2 Pulleys and Belts (TBD if I’ll stick with belt drive, cutting and splicing these things is a nightmare…)
- All included M5 fasteners, bearings, and bushings
- WIP: Re-using the control board. Boards with STM32 work great; mine is a GD32F303 on the V4.2.2 and I haven't figured out how to replace it's bootloader. If you have tips, please reach out!
The current MVP for the drivetrain is pictured below—a 3:1 gear reduction from the motor to the wheels ensures we have enough torque to avoid stalling under load.
A concern with this design is the strength of spliced belts. While it would be super neat (and further the goals of this project) to re-use the GT2 belts from the X and Y axes, I'm not sure how well a glued splice would hold up over the long-term. I currently use the printable GT2 belt-splice tool from Thingiverse to cut up the X and Y belts to proper lengths.
Another concern is the ~7mm of axle that is actually supported in the frame, while the internal bearing design is solid, I think I'll end up reworking it some to give it more support while still re-using the M5 x 45mm included bolts.
Since I'm still working on the mechanical aspect of this, the electrical design is somewhat up in the air.
I intend to re-use the main Creality control board, connected via serial to an ESP32, Pico 2W, or similar for wi-fi, since having a 4 channel stepper motor driver already included for free is a great win. I'll also re-use the provided fan for ventilation.
The current prototype (what I'm testing with) is just a perf board with 4 A4899 Stepper Motor Driver breakout boards connected to a Pico 2W, but as soon as I finish either modifying a build of Marlin to add custom Gcode commands, or find a way to properly target the GD32F303 board when compiling in Arduino IDE, I'll switch to the Creality board and update this repo.
This project is very much in alpha, if you:
- Figure out how to reprogram the GD32F303 on the V4.2.2 WITHOUT needing to glue together custom bootloaders and solder debug headers to the board.
please open a PR or drop me an issue!
This project is open source under the MIT License. Seriously, do whatever you want—just don’t forget to give credit. Happy recycling!