I've always wanted to try 3D printing an RC helicopter. It's a great design challenge to make the swashplate and transmission assemblies. I also wanted to make a small-scale model of the Mars Ingenuity helicopter, so why not combine these two project ideas? Oh, and why not build the Mars helicopter at 1:1 scale so I can have my own flying Mars helicopter copy here on Earth? So that's what I'm doing.
My goal is to 3D print as many parts as possible. The blades will be made of foamboard and I'll try to keep the assembly as light as possible to reduce power requirements and stresses on the blades. While not staying true to the real Mars helicopter design entirely (very complex rotor head design), I would still like to see a large, flybarless coaxial heli flying by the end of this project. Stay tuned...
Just when rotor testing was ramping up, the 5v regulator for servos and flight controller decided to die. But a new one is now installed and the blades have been shaped for better aerodynamics. Rotor testing and tuning can now commence as we push toward a test hop.
It's been a while since the last update... Final exams and projects ramped up--but at least now I've secured my Master's degree in rotorcraft!
The fuselage is just foamboard hot glued to the main fuselage mounting plate. I've got my flight controller (dRehmFlight VTOL: https://hackaday.io/project/174768-drehmflight-vtol) buried in there along with some 30a ESCs, 10a BEC for the huge servos, and a 1500mah 4s battery. The blades aren't done yet, but I was so excited to see this thing fully assembled. They still need beveling, taping, and balancing.
Next up is taking care of the blades, then other small issues like belt tension, then we'll try for a flight. Even if it doesn't work (I give it ~60% chance), I think I'm still going to give it a really nice paint job. Super cool having a 1:1 scale Ingenuity sitting in the living room!
I think I'll call this one "Scrappy", Ingenuity's little Earthling brother.
Hopefully we see a flight (of the real Ingenuity) tomorrow morning! I spent some time tonight getting the swashplate all setup and the 'blade grips' mounted to the main shafts. When I can find the time, the next step is hooking up electronics to see the proper swashplate actuation while the blades are rotating, and to make sure there's not too much resistance on the geared down motors. It feels fairly easy to rotate by hand, so fingers crossed it stays that way...
The fuselage consists of a single 3D printed mounting plate where the servos and motor directly mount to. I've got them all installed and the rotorshafts running through to the inside where they're driven by a belt and pulley. As you can see, we have thoroughly departed from the original Ingenuity design at this point:
Got to the shop to cut some shafts and size them up for the bearings. The skeleton is taking shape! Next up is motors installation and testing the drivetrain before securing parts (epoxy) to the shafts... Then blades...then electronics. Stay tuned.