A "chuck glider" RC conversion

[Quorneng]

Al though my posts so far seem to have concentrated of home designed lightweight EDFs I have converted a couple of RTF foamy chuck gliders.
The first was the ubiquitous LIDL which is very cheap for its size with an 830mm span.

All foam with no reinforcement.
My biggest grumble was the 5mm thick wing, tail plane and rudder trailing edges. suitably robust for a chuck glider but not ideal for a good gliding performance which was what I was after with my RC conversion.
I decided to add trailing edge extensions to bring the edge down to 1mm. It would also increase the area slightly.
For strength and simplicity I printed them in LW-PLA (the heat of printing causes the bead to foam to twice its size)
In the case of the elevator the printed extension was the elevator as it was for the ailerons.

In keeping with aerodynamic efficiency a relatively small motor was used completely covered with by streamlined cowling as well as a folding prop.
The cockpit and canopy were hollowed out enough to add a ESC, Rx and battery.

Small 3.7g servo are used for the elevator and ailerons. The rudder is fixed.

The finished conversion.

The wing trailing edge extensions are obvious.
It weighs just 229g ready to go. Flies well enough but despite the attention to aerodynamics the rather thick wings gives only a moderate glide performance.

I was on the lookout for something better!

 

[Quorneng]

Just in case you might be wondering about using no rudder note the aileron servo arms are canted forward almost 45 degrees.

This gives a strong aileron differential (more up than down). This means there is more drag on the up going aileron causing the plane to yaw in that direction giving a similar input to that of the rudder. Overall it is not quite as effective or controllable as a rudder but it does save the weight & space of the elevator servo in what is likely to be a rather restricted fuselage volume in a chuck glider RC conversion.
The next ia a conversion of the rather bigger (1.200mm span) FX707s chuck glider.

Twice the price but beautifully molded in EPPO but still with rather thick trailing edges although 3mm rather than 5mm of the LIDL Perhaps more important carbon tube reinforcement was included to stiffen the wing, tail plane and rear fuselage.
The wings tail and fin are intended to be removable held in by bolts. To save weight at the tail I removed the fittings and glued the tail plane and fin in permanently. I also glued the halves of the wing together so it was a single item but retained the 3 holding down bolts.
As before the cockpit, canopy and the under wing area were hollowed out to create suitable space.

The ailerons were added to just the outermost portion of the polyhedral wing but when the tailing edge extension is added to match of the rest of the wing it added about 12% to their area.

The complete and suitably painted with a folding prop.

An usual feature is the small 10A ESC is mounted on the outside wall of the cockpit to ensure it gets adequate cooling.
It flies very nicely and quite fast and it does glide better than the LIDL.

Whilst speed is useful when slope soaring for thermal flying it can be a disadvantage particularly in the UK where thermals tend to limited and small.
So I bought another FX707s and to be converted to have flaps to allow slow circling in thermals.

The flaps have 3 position 0,15 & 50 degrees. The ailerons are also larger to maintain roll control when flying very slowly with full flap,
The flap work very well and there is automatic elevator compensation programmed into the transmitter.

I just now need the summer and some thermals.