I was first introduced to the world of 3D printing at the Greengineering lab of my high school. My friend was printing out chess pieces to replace the previous ones he lost. I was excited at first, it was as if something was coming together out of thin air. After a while, my excitement died down, seeing as people only printed static parts, mostly models for display purposes only. I skipped out on learning how to use it because I thought, why go through the complex learning process when I have no use for it? Or so I thought I had no use for it.
I soon got into the hobby of building and flying multirotors, more specifically tricopters. The term ‘tricopter’ is derived from the fact that the aircraft utilizes 3 motors to control pitch, roll, and altitude and a servo to control yaw. This is only one of many motor configurations, but I won’t digress into the specifics. I’ve experienced a great deal of success using standard building materials such as wood and metal but found the building process quite tedious, especially after multiple crashes. During my search for a more efficient building process, I came across the idea of using the 3D printer to fabricate a frame for the tricopter, and various other parts such as the landing gear and camera tray. I was quite skeptical at first, since I was unsure of how ABS plastic would perform under all the stress encountered during flight. Fortunately, I soon discovered an online database of printable parts, enabling people to share their various 3D printed projects, and even allowing users to download the STL files: the model fed into the printer. I saw people experimenting with 3D printed multirotors, with a great deal of success. I was ecstatic, determined to integrate 3D printing in the construction process of my drones.
My first iteration of the 3D printed tricopter was almost completely self contained. The only non-3D printed parts were the wooden dowels used as the arms. Everything from the frame, down to the motor mounts came out of my schools 3D printer. It was amazing how strong the parts turned out, and how accurate the tolerances were. The bolt holes didn’t even need any widening, the bolts just fit right in. The parts fit together like a puzzle, with no slack whatsoever. Even the mechanical linkages such as the thrust vectoring mechanism in the tail worked with no slop or friction issues. I was in awe how easy the build process was, it turned hours of cutting and sanding wood into a press of a button. I was glad the airframe came together nicely, but the real question was how would it fly?
The maiden flight didn’t go so well, but this wasn’t due to the parts. It was due to programming errors, since the flight controller wasn’t set up correctly. The copter ended up taking a hard landing, snapping one of the motor mounts. Fortunately, I printed out spares of every part but the frame, so I was up and running after a quick fix. Once I set the control board correctly, the copter took off and began to hold a steady hover. Once I was confident that it was airworthy, I took it for a few laps around the field. Up in the air, I couldnt’ tell the difference between the 3D printed and the wooden version. They essentially had the same flight characteristics. There was a little bit of flex where the wooden arms secured to the frame, but this was only noticeable during hard aerobatic maneuvers. I was so confident in the airframe that I decided to put all my FPV gear on it. FPV stands for first person view, which is essentially being able to fly the tricopter as if you were actually in it. A camera is connected to a transmitter which relays the signal to video goggles on the ground. I also added a gps and autopilot functionality, it was now fully functional 3D printed drone. I loved the frame so much it became my main FPV aircraft.
Unfortunately, this tricopter is no longer around due to a signal cutout which resulted in a bad crash. However, I am working on revision 2 which is designed to be even more efficient in terms of build time. I also addressed the issue of frame flex at the boom contact points. Although the design process is still not complete, I already see the potential of 3D printing as a cost effective manufacturing method for my tricopters. This is just the beginning, and I am looking forward to what lies ahead!