Hello, dear hobbyists!

Just like many guys viewing this site, I’m here because of helicopters, and I want a bigger and bolder thing. I mean – I want a RC airplane. Sadly, Ukraine is still going through an economic crisis, which won’t let me buy everything I want, so I have to rely on the good old do-it-yourself tactics. This is my first airplane ever, so feel free to criticize and share pieces of advice. I wanted to get just a little bit of RC aircraft building experience. You’ll probably say that I’ve gone the wrong way and I should have chosen aerobatics.

Yes, that’s right, but... I’m a Russian guy, and Russians never learn from someone else’s mistakes.

Well, I found a draft of a balsa plane with a 1.5m wingspan. I decided not to draw, because I was too lazy to, and I’d otherwise have to do tons of drawing and drafting. Balsa is great but expensive, and I’d never use it, so I dumped the idea. I knew I had insulator material in my garage, so I decided to use them.

Extruded polystyrene foam (XPS) is a strong and lightweight, but the sheets that I had were quite thick, so I had to cut them. Building a foam-cutter didn’t take long – a piece of wood laminate, two pieces of fabric-based laminate and two meters of nichrome. I fixed the wire with collers from a burring machine - I had bought at a local market. The device was powered by a charger featuring a foam cutter mode. The nichrome wire: 0.5x350mm; amperage - 2.8-3.2A





Well, I made 3-8mm plates. There is also a problem – the fluff, which differs according to the type of material. BASF polystyrene (the green one) has less fluff, and the material is stronger and more flexible. Water and a sponge are the solutions to the fluff problem.


After a little finger-testing, I decided to use 5mm-thick cover and 8mm-thick formers and ribs. That was when I realized the uselessness of the draft, which provided nothing but contours. I had to study Compass and Corel Draw.

I chose the good old ceiling tile glue, as it wouldn’t destroy polystyrene and would bind even wooden parts quite well.

My first attempt to glue a stabilizer failed. The edges wouldn’t join properly, and I couldn’t angle it. I didn’t want to rebuild the foam cutter, so I had to add a device. I used my old pyrographer as a power supply unit, and the power it provided made only 5cm of the nichrome wire.


Now the stabilizer. I inserted plastic hinges into the planks.

I cut wingtips out of an alder plank.

Next come the fuselage and the wing.


The wing-fixing pin.

Servo-bearing rib carrier rod.

Aileron hinges


Covering the fuselage and the wing

Fitting the tail

Although I felt quite worried about the cowl, it turned out to be easy game. The whole thing took but one night. I had to move to garage, because there was too much dust. Briefly, I took a package of 20mm-thick plates, bolted them together, cut off prominences and polished it. I chose 20mm-thick plates, because they were easy to cut.



Now the plane is almost ready
Now it’s time to fix landing gear. I couldn’t find the all so good duraluminum and used a 50x3mm oak stick instead. Then I steam-bent it using my old coffee pot and a metal bow. Please, note the resilience of the materials and see the difference in the picture below.




I had a tape printer in my office. Thank you, dear colleagues, for my not having to beg of you to let me use it! However, they needed a Corel file, so I had rack my brain over Corel Draw a little.

I made two files with different color patterns and finally had to choose the more suitable one. The two colors took an 8m piece of tape. After a little comparative study, I gave to the yellow one.

I taped whatever I could. By the way, the tape won’t stick well to polystyrene, not even after polishing. You can solve the issue by painting the skin with water-based lacquer such as this:

That was my first taping experience, and I used the stabilizer as a training facility.
No problem. Move on.

The wing posed a little more trouble. I cut out the top, the bottom and the leading edge as a single piece. I should have cut them out separately, I guess.
I made a cutter using a piece of razor blade.
Protruding servos had always driven me nuts, so I decided to place them into the cockpit. For this reason, I had to use much longer pull rods. I tried a carbon pipe. I took a piece of 2mm wire (see the nail and the stud on the picture) and a tube-shaped piece of receiver antenna. Then I threaded the nail and glued it into the pipe using cyanoacrylate.

I concealed aileron servos in the wing.
Then I bolted the ailerons’ and rudders’ hinges with M2 screws, so that they could be removed when necessary.

The wing rested on two M6 nylon bolts.

Now it’s time for the motor frame. Draft it in Compass and view it in 3D. Then cut it out of a piece of plywood and glue it.

Now, my observations of how much the tape influenced the stabilizer’s weight.

The weight increased by 37g. Now the fuselage.

The fuselage’s weight increased by 35 g. I hadn’t weighed the wing before taping it, so I guess it would have weighed 70-80g.

And a few more pics just for conclusion.
I decided not to fix the canopy, because I didn’t like the shape and I’m intent on making another one.

Now, let me draw a little conclusion. I liked foam polystyrene because it was quite available and cheap. Later, I guess, I’ll build a few more airplanes and cover them with balsa. The wings and the fuselage are really tough, and I can safely use thinner planks next time. I didn’t have to use many tools while building – just a couple of cutters, a ruler, a scalpel, adhesive tape, clamps, two packs of erasers.


Parameters:
length 1340mm
wingspan 1500mm
central rib 360mm
end rib 180mm

The whole thing not equipped with a motor and a battery weighed 1670g.

I can’t boast a good theory background, so I’d be happy to use a little help from experienced hobbyists in choosing a propeller and a motor.

Thank you for your patience!
This is the translated version. You can read the original Russian article here.