FTB Flying Test Bed (oz14287)

About this Plan

FTB - Flying Test Bed. Radio control sport model.

Quote: "This flying test bed model (FTB) was built several years ago specifically for test-flying a variety of small engines, generally in the.5cc -1cc range from my modest collection of mostly diesel engines. It has done that well and I`m delighted that has proved to be a particularly nice handling sport r/c model as a spinoff.

The one slightly different feature of this model is the engine mounting arrangement. The idea was to use variety of simple interchangeable mounts, made practical using the 3D print process that became readily available some years ago. I am no techno wizard and still know next to nothing about the process, but following discussion with a modelling mate who has a printer, I produced a sketch for what I considered to be a simple and practical unit which might work. A recently prepared drawing for this mount is attached here [see supplement file]. Dave produced about half a dozen samples using several different filaments and I used have several of them on this model, each with a different engine, hence the model name.

There is nothing particularly unusual about the rest of the model. It is a simple design and quite straightforward to build. Construction follows regular time-honoured techniques.

The fuselage is a simple box assembled from 3/16" sq balsa sticks. The wing carrying pylon is simply built from three laminations of 3/32" balsa and the wing and flying tailplane are built from a variety of balsa sticks and 1/16" ribs. I generally use 'Titebond' aliphatic glue for most of the woodwork - the red label brew which sands well. The prototype is covered with HK plastic film.

Anyone who has built a basic 2 or 3 function r/c trainer along the lines of the iconic 'Tomboy' or similar will have no trouble with this one. If the 3D printed mount is of no interest it would be quite easy to build in a pair of wooden beam mounts or simply bolt an electric motor or radial-mount Cox .049 type engine to the front former.

Flying the model is quite straightforward. All flights to date have used small free-flight engines with no throttle control and have thus been hand-launched. Depending on the engine used, it can be mildly aerobatic. Engines used to date have been Mills .75, DC Merlin, MP Jet .040, PAW .06, Redfin SAM 50, and it has handled all with no incidents. It seemed to struggle a little with the Mills .75 and was most agile with the DC Merlin.

I was playing with this model when the 'Roving Redfin' SAM 50 passed through Australia about 2 years ago and I was able to intercept that and make several flights with it on the front. It was a nice match with result I have since purchased one of these little gems with r/c carb and am currently in the process of modifying the model, inclusion of throttle servo etc, and looking forward to more flights with it in the future. Alan W"

Direct submission to Outerzone.

Quote: "Hi Mary and Steve, Season`s greetings to you both. Please find attached herewith one A1 size PDF drawing recently prepared for this model and a separate A3 drawing for the 3D printed engine mount specifically designed to go with it. I built this model several years ago. It has had plenty of use during that time and it still graces my hangar. I recently withdrew it from the airworthy list and am currently refurbishing it and modifying it to include throttle control for the Redfin SAM 50 engine. It has proved to be a nice little flier and I submit the details here for your consideration to share via your website... This will be my last submission for the year. Please confirm whether it is of interest. I'll look forward to more building in the New Year....
Merry Xmas, Alan W"

Supplementary file notes

3D Engine mount drawing.

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