Scratch-Built RC Plane
For the last year or so, I have been designing and building an RC plane from scratch. This project has involved designing it in CAD, picking and buying parts, and learning multiple new skills, including setting up an Ardupilot flight controller and working with foam. While a skilled builder could easily make a plane from scratch given a month or two, it has taken me much longer due to having to learn how to make one in addition to actually designing and building the plane. The vast majority of the time so far has been spent on prototyping and iterations, going from a twin boom plane with a folded wing made from foam board to a similar plane with a simpler, cut and creased wing, to the final iteration, a much simpler and more reliable design with the same wing as the previous design, but with the fuselage cut out of EPP foam rather than being folded from foam board in order to increase strength and impact resistance because crashes are a fact of life.
-7/1/2026
Entry 1 - 7/1/2026
Today, the CAD model for design iteration #3 was finished, taking what I learned from versions 1 and 2 and refining them to be more durable, simpler, and a more reliable design overall. This involved a redesign of the fuselage and tail in order to transition from a twin-boom design not unlike a P-38 or OV-10, to a more conventional, high-wing twin-engine design similar to the De Havilland Dash 8. A render of the design is included below.
Entry 2 - 7/13/2026
Today, I have finished picking the final piece of the aircraft I needed to select, the foam type for the fuselage. While I had planned to use Flitetest-style foam board for the wings and tail surfaces, I planned on cutting the fuselage from solid foam blocks using a hot wire. The foam to use, however, was a difficult question to answer. I had many different options, with many different material characteristics. Right away, I thought that a foam called expanded polypropylene, or EPP, would be perfect. EPP presents the perfect combination of being relatively lightweight, although there are slightly lighter alternatives and being almost indestructible and being able to bounce back after impacts that cause dents, leading to its use in cars and bike helmets. As I looked around online for it, however, I found that it is very difficult and expensive to obtain, and when you can, it is usually in thin sheets. This means that I had to look elsewhere in order to find a foam that can actually be obtained in a feasible and affordable manner. After researching many different foam types, I assembled a spreadsheet with 5 candidates and their characteristics and feasibility. After thinking about my choices, I eventually settled on a foam called Extruded Polystyrene (XPS), which, while more brittle than EPP, is much easier to obtain due to its main use for insulation foam. A screenshot of my data table is displayed below.
Entry 3 - 8/11/2026
Recently, I have taken a break from directly making parts for the plane in order to build a hot wire foam cutter for cutting the airframe. I have been doing this using an old brushed speed controller to control heat, a servo tester for inputs, and a AA battery bank for power. These work to heat a hot wire bow made of nichrome wire and a PVC pipe frame. In addition to assembling a hot wire bow, I have also bought a large sheet of XPS foam for making the plane. Some readers may have noticed a gap in my first two entries and this one, and that is due to several unrelated events as well as a fun fly event at my local RC club, West Coast RC Flyers.
Entry 4 - 9/3/2026
Since my last entry, I have assembled the bow almost completely, save for connecting in nichrome wire, for which I am currently waiting for the final few parts, and connecting the main electronics up to the frame itself. It may be a few weeks while I wait for the fial connectors to arrive and then finish the bow before I write another entry. In the meantime, I will be trying to update a brief tangent that I went on about redesigning the entire Amtrak network with an unlimited budget.