Over the past few posts I’ve been describing goals and motivations for future Sawppy evolution. Mostly in terms of my own efforts, but with a few notes reminding me to leave options open for others working on neat stuff like Ardupilot adaptation. This post will be a summary, grouped by common themes with links to individual items. Most of these goals for improvement are the result of feedback from people who have liked my Sawppy design enough to spend their own time and money to build their own rover. I am thankful for every one who have reached out to me with questions, suggestions, and my favorite part: pictures and videos of their rovers roaming about. I always love seeing other Sawppy rovers running around.
Fix Mechanical Shortcomings
I’m thankful this section is much shorter than I had originally expected. I’m not a mechanical engineer and I honestly expected more fundamental mechanical issues than what has cropped up to date.
- Increase robustness of differential bar so a brace would not be required.
- Limit range of motion of bogie attachment point in order to prevent over-rotation.
Make Construction Easier
Everything here can be traced back to feedback from one or more rover builders.
- Change how 3D printed parts are fastened to metal structural beams in order to reduce number of fasteners used, and avoid specialty fasteners.
- Reduce need for precision specialty tools such as 8mm reamers.
- Reduce metalworking steps such as cutting E-clip slots.
- Help keep track of 3D-printed parts by stamping identifiers into STL.
- Help make 3D printing easier by rotating parts for print bed layout.
Improve World Friendliness
I’ve learned there’s more to designing a world-friendly rover than just working in metric.
- Move away from using LX-16A serial bus servos due to poor worldwide availability and evaluate use of more commonly available hardware components.
- Reduce (or eliminate) use of heat-set inserts due to wide variation of sizes and availability.
- Change from 15mm aluminum extrusion beams and use 20mm beams instead. The latter is far more commonly available worldwide, especially in maker circles as they are commonly used for 3D printer chassis. Reducing fasteners and avoiding specialty fasteners (as stated above) should also make parts easier to procure worldwide.
Smoother Rover Operations
In contrast, most of this section were derived from my own experience taking Sawppy around.
- Give Sawppy a faster way to adjust steering trim.
- Make it easier to carry Sawppy around.
- Design to simplify troubleshooting and repair.
That is a pretty long list of things I want to change! And on the way there, I also need to keep in mind of what I would rather not change.
[Title image: Sawppy and I at Sparklecon 2020]