Winner Trainer


Up / terug

A variation of the Record Trainer is the ENLARGED version – in this instance 115% of the original. Power is to come from the Webra Record's big brother, the 2,5 cc “Winner”. For comparison, the standard-sized model is placed over the enlarged one.

In the case of my big trainer the wing is no longer a simple sheet affair but a deep, hollow profile with flaps. The fuselage is not a balsa profile but made of redwood.

After re-reading Ron Moulton's iconic “Control Line Manual” it was decided to create a fuel tank that fits between the engine's backplate and the wing leading edge in order to keep the fuel line as short as possible. Reason for this is that my models often suffer from fuel starvation when performing stunts.

Instead of the usual wedge-shape this tank will be a simple box affair, the idea being to keep the fuel line close to the fuselage and cancel out as much centrifugal and gravitational force as possible. I find it helpful to make a card prototype first. The sheet metal is from a biscuit contaiiner. Good tin snips are a boon when it comes to following the score lines.

Sharp folds make for a better result. The tools are somewhat improvised but that makes modelling more fun.

Here the box tank starts to take shape. Holes for the various tubes are made prior to the folding process and the card prototype is especially reassuring in this step. Notice that the tank is made up from a single piece of sheet metal. There are pro's and con's to this, but I often struggle to keep loose side pieces in position while soldering.

All piping faces the front of the model where the motor is located and the airstream comes from. The two tubes on top of the tank are a filler vent (which can be blocked off before takeoff) and a pressure inlet (Uniflow principle).

My first flapdriver, soldered up from all sorts of leftovers. The U-shaped connector, that links the two flaps, hinges through a brass tube soldered to a saddle that in turn sits on the trailing edge of the wing (see next picture).

Wing trailing edge with flap driver mounted.

Christmas is upon us and the Winner Trainer is decorated too.

Just a few more coats of clear dope to go before the final assembly is taken to hand.

The Webra Winner 2,5 cc engine had spent decades in a shed after a hard life in combat models with its previous owner. In spite of all the nicks and the cut down needle, it runs beautifully.

If you look closely, you can see the piano wire tail skid. The original design does not have this feature, but the forward location of the wheels leads to the tail slamming down in hard landings and that can crack the slim fuselage if there is no shock absorption.

This is my first model with flaps. The secondary push-pull rod is a strip of bamboo with short pieces of wire at each end.

The primary push-pull rod is a piece of bicycle spoke that runs through the wing. The bell crank is tucked under the wing where it should be and the “up” arm is the rearward one, which is supposed to be good for yaw in aerobatics.

Once satisfied with the flying characteristics I will discard the rather complex adjustable guide for the leadouts.

Here the original 1,5 cc model is placed next to the 15% enlarged version.




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