Flying Stick (oz1829)

About this Plan

Flying Stick. Free flight model.

This is a 'Mini-Vintage' model of the full size original Flying Stick by Frank Ehling which first appeared in the Frank Zaic 1937 yearbook. This here is a later half-size version, for CO2 or small electric power.

Quote: "THIS YEAR'S VISIT to Old Warden Scale Day reinforced my growing suspicions that my R/C flying there was likely to be several curtailed, and that I should arm myself with a suitable free-flight model ready for Vintage Weekend later in the year. As I am rather prone to rush into these things, I obtained a Telco Turbo 6000 at Woodvale which left all of a fortnight before the event - plenty of time to sort out and build a model.

After a week, I still had not settled on anything, and time was now running out. What I wanted was something simple, very quick to build - and Vintage. Whilst checking some other details in the 1937 Zaic Yearbook, my eye was taken by the Ehling Flying Stick. What a delightfully, attractively ugly beast! Then the penny dropped; here was my subject for CO2. Reduce it to half size and away we go - or so I thought.

A few preliminary and tentative pokes at the calculator next day suggested that 45% was about as big as I could make the model to avoid it being underpowered, so the lunch-hour was occupied with marking up a Xerox copy of the plan with the various dimensions. I couldn't waste time working overtime that night - it was now Monday 11th August, with just six days to go!

The plans were very roughly drawn (on the back of an instruction sheet - no envelope big enough!) and construction started. By the time the midnight oil ran low, the fuselage was standing on its undercarriage on the bench. Second night saw the completion of the airframe; third night had it covered.

A tale of trimming The night of Thursday 14th brought poor weather, but the Gods were kind on Friday and out we went for test flights. The previous evening I had spent some time fashioning an ounce of lead to fit in the nose to bring the CG to where I thought it should be. The first handlaunch resulted in a dive for Mother Earth that would have done credit to the second half of a ballistic missile's flight, so out with the lead. This time the glide angle improved considerably; it almost reached 45 degrees! Several more hand-glides proved that (a) Frank had definitely put the wheels in the right place and (b) the tail required some packing - this with the CG at 75% to 80% of the chord! Now I know that Aeromodeller readers are going to laugh at this R/C intruder trespassing into the magic realm of free flight, and tripping up in the process, but I had made these gadgets work in the dim and distant past, so I was well equipped with bits of 1/32 sheet, and in my case, my workshop was only through the gate; nice to have a field so handy! The slices of packing were inserted one at a time, and by the time I had 3/32 under the tail trailing edge I was beginning to think that the lemon-yellow tissue was an appropriate choice! More packing was inserted - this time under the wing leading edge and by now it did begin to show signs of behaving like an aero-plane instead of a misguided missile!

The field I fly in has a steep rise of some forty or fifty feet, so up to the top I went to try some gas charges. All these did was to very slightly extend the glide, so I now started to crank up the Telco's power. Finally, in sheer desperation, I wound the Telco up to full power, gave it a liquid charge and flipped the prop. Utter astonishment - she rose in a steep climb, daintily dipped the left wing in the merest hint of a stall - then continued in a gentle and steady climb, gradually levelling out into a cruise which almost took it out of the field. The tail was then re-adjusted to give a tight right turn; liquid charge and away again. This time the power-stall was almost non-existent and the flight was a joy to watch, confirming the dragonfly appearance as it quickly purred round in the calm evening air.

Building hints: Now, I don't need to tell you how to build a model like this but do keep it light. My first one weighed four ounces, which is heavy. By the time you read this, I shall have built another, aiming to get the weight down to no more than three ounces. Use Jap tissue with just one coat of dope. The fuselage booms should be given two coats of dope, sanding after each coat before building the fuselage. I have departed from the original design by incorporating the rigging angles into the pod and the tail-seat of the boom. I have also halved the number of ribs in the wing and tailplane.

The wingtips require a degree of explanation. The spar ends should be prepared as shown. The sheet tip rib and underside sheet are glued in place with packing between sheeting and board. The tips can then be laminated directly to the sheeting after all the ribs, leading edge and trailing edge are in place. If you use cyano, you can complete the tips within a very short space of time by soaking the 1/32 strips in hot water - I run them under the hot tap - and cyanoing in place whilst still hot and wet (the strips, that is). Run around the tips with a heatshrink iron when you lift them from the board to dry them out and sand to shape - ten minutes is all it takes.

You will find that due to the long tail moment trimming is easy - quite large adjustments can be made without getting into trouble. Ensure the CG is at not less than 70% of the wing-chord and you should be OK. I'm very pleased with mine and intend to build the full-size version and stuff two mini-servos into it; thinks; what about a twice-size version? Where's that calculator! "

Supplementary file notes

Article.

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