Finding a cheap base plane
One famous base plane for cheap R/C conversions is the Lidl Glider. Unfortunately, this model has become quite rare and it’s hard to get one. But the idea of using a cheap toy plane to learn RC flight is certainly a good one.
I finally settled on this floam glider toy from Aliexpress. This is an incredible foam plane for $2 ! I bought a few to have spare wings or fuselage for my next crashes.
I later discovered this foam plane is everywhere. Here it is at a local shop, same price.
This toy is a very simple design, and you will notice it already flies very well by itself. The horizontal stabilizer can has two mounting slots : one for straight flight and one for acro / loops. We will use the straight flight slot for the stabilizer, but don’t fill the acro slot just yet, we will push the elevator servo inside :
The plane surprisingly retains good flight characteristics after adding the R/C gear, as you will see.
RC setup
I tried 2 different RC setups :
- flaperons + elevator servo
- ailerons on shared servo + elevator servo
The setup that I liked the most was the one with ailerons on a shared servo. The flaps made the aircraft unstable when deployed, and made little difference in approach speed. Also, it is simpler and lighter with just one servo.
Mechanical
The wing is glued on the fuselage, and there are slots under the fuselage for the electronics. The single servo for the ailerons is mounted in the center of the wing, and the elevator servo is just pushed in the “acro” slot of the tail.
The motor mount is a set of 2 3D printed parts : a foam-side support and a motor plate. This setup allows the motor and its mount to be easily removed and replaced. The motor mounts on the plate with its own M2 screws, and the motor plate mounts on the fuselage with self-tapping M2 screws.
and the motor is screwed on the plate with M2 screws.
Electronics and BOM
Here’s the BOM :
- 2x or 3x LiPo batteries with their charger (3 are plenty, as you will see in Flying the plane)
- 2x 2G Servos
- 1x mini ESC
- 1x Control horns
- 1x Piano wire of the right diameter
- 1x Props
For the ESC, be very careful not to buy the long red/blue ones ! I made the mistake of buying one, and while they claim to work at 2s, they don’t. They do not work above 7.4V, and when they do, they are very noisy.
Transmitter - Receiver
If you have a transmitter and receiver, just use them :)
if not, the RadioMaster Pocket Crush is a great complement as it is feature-rich (ELRS + EdgeTX !) and pocket-sized. This is what I use and I love it ! Another solid option is the Tx16s, the bigger brother of the Pocket Crush, which also runs EdgeTX but also features a color touch screen for easy configuration.
Serial or PWM receiver
If you have a PWM receiver, you can use it directly and plug the servo / ESC wires directly to the receiver. If you have a serial receiver, you will need to use a demultiplxer to connect the receiver to the ESC / servo wires. I am using a custom-built demux based on ESP32. I may share details of the project on this blog if it gets to a publishable state. But there are off-the-shelf demuxes available on the market, so you can probably get away with a cheaper one.
Flying
Ready to fly ? Read on : Flying the plane