Here is the latest revision of my folding drone! Feel free to check out my previous revisions and pages related to all my previous work related to this design.
Ok, more about Folding Drone V3 below…
- New design
- Snap joint enclosure considerations
- Custom arduino flight controller
- GPS, ultrasonic sensors, lidar, barometer, gyroscope, compass
- Packaging improvements (battery, power distribution board, cameras)
Two drones deep… the third one had to look more compelling. To accomplish this, I committed to re-designing the main body. This meant giving the drone a more angular look, and more personality by adding eyes to the nose. Personality, though most important in humans, doesn’t do much good for a mechanical object. I plan on using its personality (eyes) to house ultrasonic sensors in the future. This will be used to prevent the drone from crashing into things from the front. Side, bottom, and rear sensors would also be great for full 2∏ awareness. In addition, I also shortened the body a bit for a more compact design, and slimmed down the arms. Lastly, I designed a new battery cover to get away from the switch mechanism to reduce parts count as well as make it easier and fancier to use.
Below is a concept for how I may store extra electronics such as an FPV transmitter. In addition, the shelled space gives routings space for the eye mounted ultrasonic sensors.
Snap Joint Battery Cover
My inspiration for this design came from the snap joint that you see on common TV battery remote covers. This design feature takes advantage of a plastic materials deformation in the elastic region of its stress strain curve. This means that if the snap joint is designed properly, it will snap back to its original position rather than remain or fail. My design is based around a cantilever snap joint and was designed with calculations based on key cantilever snap joint geometry. Below is an image of the geometry that was key to this design.
I wanted to take these principles of snap joint design and apply them to my unique case. In my design, I had to add extra geometry for the joint to properly slot into the drone body. In addition, I wanted buttons to allow for intuitive assembly/ dissasembly of the battery cover. This lead to the cross section as seen below. You can see the similarities it shares with the cantilever snap joint above adapted to my battery cover design constraints.
To test my design, I performed an FEA to get an idea of what its deflection would look like. Based off simulation alone, the design would deflect the proper distance to disassemble from the drone body.
Every square millimeter of space in the drone is used to house some sort of electrical component. The flight controller for instance mounts on the bottom cover while leaving just enough space for the receiver to mount in its designated spot. The arms of the drone were used to conveniently store the speed controller boards.