Saturday, April 4, 2015

The Process of Building R/C Aircraft

Fleet Finch, a WW II trainer aircraft.

Zach Neal

The ability to focus on a project is a wonderful thing. When I built a 56” wingspan Fleet Finch for radio control, it was sheer luxury to be able to pin a wing or a stabilizer down to a board and just leave it. I owned a small house. I did not have a dog, a wife or any kids. If I left something on the workbench, it would be there a few days later when I went back to work on the model.

When building from plans for the very first time, the best thing is to read the instructions and study the plans. It probably is better to begin with Step One in the instructions. However, with a little experience, a builder might build small components quickly, without a lot of reference to the manual. 

It’s easy enough to build the stabilizer, the vertical fin, the elevator and rudder components and just set them aside.

Wings are often built in halves and a biplane has an upper and lower wing. Before fitting the bottom wing, it’s necessary to have the fuselage in some advanced stage of framework completion. Yet the motor mount and cowling don’t necessarily have to be complete to dry-fit the fuselage to the bottom wing.

The top wing can be mounted and properly fitted to the fuselage struts in parasol fashion, the N struts on the outer wings can be built and fitted carefully later.

The wings and fuselage can be covered later, when the builder is sure everything is installed correctly, everything works, and nothing has been forgotten.

In short, it’s a process. It’s a process that benefits from some experience.

When it’s time to make the engine mount, the front bulkhead is drilled. You need holes in the proper place for mounting bolts, a control cable or pushrod, holes for fuel delivery and the pressure/vent nipple hook-up. A smart builder would have all that ready before beginning assembly of the basic fuselage framework.

At about the hallway point, all of the framework, the landing gear, flying surfaces, control systems, fuel tank, everything can be fitted, bolted and slipped together. The aircraft is a fully-assembled skeleton sitting on the workbench. The builder can turn on the radio switch, plug in the battery and test all systems. If it’s electric, you can run the motor because you don’t have to worry about castor oil getting all over it. Even then there can still be hundreds of hours of labour before the flying model is completed. The Finch had been designed for an electric motor and gearbox with eighteen cells. 

Never mind that everything shown was ten or fifteen years out of date and every aspect of electric flight had changed. I wanted to run it on hot fuel, alcohol, castor-oil and nitromethane. I didn’t have any big problems modifying the kit and the parts available or making my own. It merely took time, visualization of a required part, some drawing ability, and a few tools. Over the course of seventeen years, I built many kits, bought a couple of used planes and designed about four dozen of my own. 

The last plane I designed was a million times better than the first one. The funny thing was the first one actually flew pretty well.

My old man wanted to get into radio control, but he didn’t know anything about the hook-ups—the radio system, the servos and pushrods. Someone suggested he get a kit or two and build them. Join the club and learn how to fly them. After a couple of R/C kits the old bugger was back to designing his own planes. He liked the idea of electric flight and the kits of the day were all shit, no ailerons, no power, basically clunky stuff designed by enthusiastic amateurs. My old man’s woodwork and covering were as good as anyone’s and better than ninety percent of the club fliers, admittedly kit-builders and sport-flyers, around here.

My old man taught me a lot. I watched that man, and after building hundreds of rubber band models, he really was a craftsman in the sense of miniature carpentry, with knife, sanding block, small saws, grinders, files and drills.

Virtually all of the skills required to build a flying radio control model are relevant, in fact highly-useful in building and flying a full-sized aircraft. It’s just a lot more expensive. The stakes are higher and the price of a mistake goes up drastically. But basically it is the exact same set of skills.

One of those skills is the ability to focus, to look ahead a few steps and see what is required. One of the skills is analysis. The ability to look at he plans and to realize that they can’t possibly tell you every little thing that you need to know.

A certain level of skill is presumed with every kit bought and sold. If a radio-control model aircraft kit is intended for beginners, it will be advertised as such.

My Fleet Finch was a scale model, the kit was intended for experts. My skills were such that it was well-built and well-engineered. The designer of the kit, made some serious errors and I would have done quite a few things differently. The design was idiosyncratic, and drew heavily on some techniques that the designer clearly didn’t invent. He was unduly influenced.

My heat-shrink Mylar covering job was very good without being professional—nine year old kids in China do a fantastic job of covering some of the new park flyers for example.

As far as professional scale competition, my plane would have been the most amateurish thing there. 

That really wasn’t my focus with that particular airplane.

All I really wanted, (and I bought that kit for $60.00 at a buddy’s fire sale, from a guy called Ray Duzek), was a big and colourful biplane to fly. It had adequate power with an O.S. 40 FP and it was fully aerobatic.

It flew just like the real thing, which is to say it took a light touch, and coordinating rudder with ailerons, elevator, throttle, etc. It took a year and a half to build that plane.

Even my old man was impressed.

I don’t know if I’ll ever get back into flying or not.

It’s a question of time, money and commitment.

I still have a Fokker D-VII and all the equipment to fly it.

I think it’s a question of wanting it badly enough.

Maybe I just don’t have time for it anymore.


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