These are the fully 3D printed T4 (quadcopter), Mini T4 (quadcopter), and T6 (coaxial hexacopter) designs I've posted on Thingiverse.com (aside: "T" is for Tubular). The comments section on Thingiverse doesn't provide a great place for discussing designs so I've created this topic here instead.
These designs are based on a tubular arm with a vertical "I" beam running down the centre. This design seems to be very strong and rigid and all of these designs are very stable in flight.
Other common features include:
- motor wiring is routed through the arms and down into an enclosed (ventilated) power and ESC tray.
- batteries are located in the centre of rotation (T6 is designed for dual batteries).
- bevelled cable "tunnels" provide a way to route cables between the power tray and top plate.
- Top plate is designed for Pixhawk or APM flight controllers with elevated GPS.
- Bottom tray has mounting points for a Tarot Gimbal.
- Optional long and short legs include "springy" feet. The legs are designed so the 3D printed threads "wrap around" the arms which makes them quite strong for their length.
- Sketchup files are included so folks can modify both designs to suit their needs.
I figure I've put hundreds of hours into these designs with prototypes and drawing time. I'd love to get feedback from anyone who makes one. Together we can improve these designs for everyone's benefit.