Felix (oz14195)

About this Plan

Felix. Radio control slope soarer model, for 2 channels.

Quote: "Felix. More than nine lives with this sweet little pussy cat.

The Felix was designed around 1986 as a do it all trainer and in fact pictures were first published shortly after that. It had been intended to be a possible kit to introduce folk to radio gliding from first principles and take them through to aileron aerobatics and maybe even into powered flight.

The prototypes did just that and a few are still in regular use, the slope aerobatic machine being particularly useful since it will perform most aerobatics quite nicely indeed.

Decide where you want to start. The rudder/elevator model will fly off the line. Full height tows and bungee launches are possible but it has to be some extra special sort of lift to keep it up beyond two minutes or so. Still. you get plenty of practice at launching and landing - if extended thermalling is what you want, don't build a Felix.

The aileron/elevator model is much more fun. It has a good performance either way up and can be 'put through the book' without too much difficulty. Not that I would expect you to out-score a dedicated aerobatic machine. You can, however, have as much challenge at a fraction of the work and expense.

The wings: The original models used veneer covered, expanded polystyrene foam cores. Simply add a leading edge, angle the tips off, sand to dihedral angle and epoxy together with a cover strip of veneer to reinforce the joint. The aileron wing has no dihedral and the trailing edge is cut back to make the ailerons. Clad the exposed surfaces with veneer and hinge with suitable tape.

The built up wing is not much more difficult and the drawing shows how it goes together.

Get gluing: We state 3/16 balsa for the sides but you could probably manage quite nicely with 3/32. 3/16 medium will be adequate for the tailplane and the bowden cable is bent to make a suitable connection to the elevator.

1/16 sheeting top and bottom is adequate though you will need some reinforcement where the tow hook would go.

The fin post supports the 'T' tail and is 1/ 16 balsa sheet onto a 1/4 x 1/8 frame. This fits neatly between the sides as shown and houses the elevator cable.

One delightful little shortcut that I use is the neat 'Radio Active' plastic clevis which has a brass ferrule in there to give adjustment. These are usable for most things you can think of.

Where a rudder is fitted, make this from soft 1/4 in sheet and if it is decided to convert to ailerons later, this can be glued up solid.

The aileron linkage is easy enough, the rudder installation is simply converted by the addition of a couple of cranked links coming through a slot in the fuselage sides. You could of course bury the aileron servo in the wing and use torque arms if you prefer.

The drawing shows the built up and foam wings. I would be very surprised if anyone has trouble cutting a set of ribs and most clubs have a wing cutter. The standards are not that demanding and it would be good experience to cut a few cores.

It's all on the drawing: No, you don't need much guidance from me. You can use plenty of rudder or aileron movement but keep the elevator movement small. Small even by sports standards, a Tx with rates on is useful here. We suggest 5/16 up and down but that's probably too much - one way to find out of course. If the model screws itself in knots at the top of a loop, the chances are that you have too much movement. Installing radio gear and covering the model will not cause any problems. Not much to go wrong is there?

The drawings are intended to be a guide, make changes if you must but do get the centre of gravity right. Makes all the difference.

Flying: Bungee launches will tend to be a bit like a catapult to start as the small model will accelerate quickly away. A hand tow will also benefit from a bit of tension before release. Just keep it moving and haul back on the stick.

Like many other models, it can be flown in light lift but it is much more fun when there is a bit of a blow. The aerobatic version is well capable of doing the early achievement schemes, keep trying something new, eh?"

Direct submission to Outerzone.

Quote: "Hi Mary & Steve, Please find attached plan and article for Felix, designed by Chas Gardiner. Details as follows:

Name: Felix
Span: 46" (1168mm)
Designer: Chas Gardiner
Publisher: Silent Flight (No. 17)
Date: Aug/Sep 1994
Description: 2 Channel Slope Soarer Trainer

Thank you again for your continuing and massive contribution to the hobby. I'll be sure to send you some more as I come across them. Kind regards, Ian Salmon."

Supplementary file notes

ARticle.

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