Stability of autonomous flying vehicles is particularly hard indoors due to lack of GPS as well as tight corridors they must navigate. A coworker mentioned angled motor mounts being used across the UAV industry for larger vehicles to help improve stability. Having some spare time a project was created to investigate.

Working with the existing drone we had deployed in a production was a key factor. We could not alter the frame in any way so a new mount would have to fit these constraints. After finding the maximum possible angle that could fit into this frame, we then worked backwards to see what other angles might be beneficial.

Four different angles including our current design of zero angle were decided upon so the design process began. The hardest part was finding angles that would allow for mounting hardware to pass threw the new mount and frame while also allowing for the motor itself to be attached to the new mount. We quickly found out the mounting hardware would collided if the angle wasn't just right. Another issue we ran across is that we were using 3D printed mounts for testing. While a part looks great on the screen when using Fusion 360, it does not equate to a real world part. Thin walls and 3D printing while trying to avoid using support quickly became an issue. After several revisions and angle tweaks we ended up with 4 working prototypes.

After completely the prototypes, flight testing began. Each set of angled mounts were testing across several categories that included stability, noise introduced due to the new angles and control near objects such as walls and the ground as well. After completing all flights we analyzed all of the data. It was clear at the end which angled mount showed the most promise.

The chosen mount was then taken back into Fusion 360 and cleaned up to help manufacturing when it came time to retrofit the current fleet of drones with the new motor mounts. This included putting indicators for where each mount should be installed on the drone, updating the bill of materials for the vehicle and showing the manufacturing team how to properly install the new mounts.