NOTE: This is still a work in progress, but the basic design works and there is some web enabled remote control. Some work still to do to make it capable of being autonomous.
I've had an idea to build a robot for a while. I wanted something that can be built upon over time and that can grow in size as I develop it. Ultimately, I want to make it a re-useable platform that can be re-purposed easily.
This is how the robot currently looks in action: https://youtu.be/3RZjhjSIZLE
Still to do:
- Improve and print on the battery shelf (Batteries are currently held on with velcro strips).
- Design or find an STL for an ultrasonic range finder
- Add Raspberry Pi camera or webcam.
- Some basic documentation on assembly
The uploaded OBJ file isn't for printing - it's just to show the overall design in one file.
Things you'll need if you want to make one of these:
- Raspberry Pi Zero W (or just a zero if you don't want wifi)
- PCA9685 16 Channel Servo driver board
- Some 2020 Aluminium Profile (alternatively, you can print this).
- Some M2.5 standoffs, nuts and bolts.
- Some M3, M4 & M5 screws and t-slot nuts (the nuts can be printed).
- At least 2 Servo motors (FS5106R or similar will fit).
- USB powerbank for the Pi
- At least 4xAA for the motors.
For the code, I'm using http://johnny-five.io/ and Node.js.
What you'll need to print:
- 2 or more servo mounts
- 1 Pi_Zero_16_PWM_Base
- as many wheels as you need
Note that I'm using Lego technic tracks and lego wheels for the idler wheels. You can pick up these fairly cheaply. I know I could have printed treads and idler wheels, but just seemed easier not to re-invent the wheel (sorry), Some links below to help you find these if you need them. For the idler wheels, and M3 bolt fits perfectly through these while allowing them to spin freely.
Idler wheels: https://www.brickowl.com/catalog/lego-wheel-rim-30-x-20-with-no-pinholes-with-reinforced-rim-56145
All design files and code will be on github at https://github.com/stuartmunn/Pi-Zero-Robot
I welcome any suggestions, improvements that you make on this.
29/08/2018 - redesigned servo mounts + github
The orginal servo mount was a bit delicate. Now split in two to make it easier to print.
Project files are now on GitHub where there should also be some basic test code soon.
03/09/2018 - Idler wheel supports
Like it says on the tin, added idler wheel supports for tracks. I've designed the servo wheels for lego technics tracks.
05/09/2018 - Test Drive
There's now a basic program on GitHub to allow basic control from an SSH shell. Uploaded a video showing the robot moving about.
Also uploaded a PDF file with some general instructions.
13/09/2018 - Web based control
No design updates, but there's now web enabled control over on github. Requires diet & diet-static npm module to run.
Added some big wheels to use instead of the robot being tracked. Using the lego tracks as a 'tyre' to give the wheels a good grip. It performs better with the big wheels, both in it's ability to get over obstacles and (not surprisingly) for speed.