Ordering the wings next week!!!

RG 15A 8.9% 160mm cord…. that should cut the air nicely no?
http://www.ae.illinois.edu/m-selig/ads/afplots/rg15.gif
thick enough to fit in some 8g servos. If one servos per aileron was not strong enough, could always put a second one.

That should make it a nice slope soarer… UK is the right place for that 🙂

Finding a used fuselage from a high performance glider could minimise the work…

Conversation with Bruno Gaboriaux – Colab Systems

I had a long conversation with Bruno who is a model plane builder with long experience with this concept of wings. (Sounds like he’s been involved in building Lucien’s prototypes from when Lucien invented the concept)

At first we discussed about the air-foil profile of the wings.  His opinion was the RG-15 profile was just for performances.  It would fly fast, but he prefers using a FX-62k profile that has been design for better handling flaps.
Perhaps we should build the prototype using the RG-15 and see how it goes, knowing Bruno has the experience of the FX 62-K-153/20, we could always fall back to this if ever RG-15 was giving us issues and that we needed more brake power.

He then explained me the proportions to respect.  They are very simple: the back wing has to be 2 cords further back and 2 cords further down.  The tail of the plain being 3 cords away.

Side view (corrections / suggestions by Bruno)

Something he mentioned is to use balsa leading and trailing edges that we can by from a local model shop.  It helps making strong solid wings saving us using fibre glass or carbon rods.

He prefers to use tricycle landing gear.

He send me two documents.

One is just pictures of an existing model converted to the COLAB System

WAYFERER COLAB (pdf)

The second document in French who describes more in detail the COLAB.

Initiation_au_COLAB

A bit of math

Starting on the bases of a total of 3m of wings with a cord of 16cm, that gives us a surface of 300cm x 16cm = 4 800cm²
If we aim for a plane of about 1kg and that we add 4l, that gives us around 5000g/48dm² ≈ 104g/dm² (commonly acceptable values for the wing load can go up to 150g/dm²)

The wings

Information on how wings fly: http://www.cfse.ch/site/topics-wings.htm

Links:

Notes:

All the experienced modellers I’ve met, each time I mentioned heavy lift, would always come up with the RG-15 profile… must be something about it 🙂

profile RG15 A ?? 150~160mm cord, wingspan 1.5m
Ailerons of about 20% on all the lengths

The wings would be cut into a block of foam using a hot wire.

The wing will be reinforced by a carbon tube (8~10mm?)

A layer of grade 160 fibre glass and a thin layer of balsa is added around the foam core (sounds solid to me).  Covered with solar film, the wings will have a nice gloss finish. (Is it a sandwiched wing?)

rg15a213

This is a Rolf Girsberger RG 15A 2.5/13.0 air-foil

rg15a111

Rolf Girsberger RG 15A-1.8/11.0 air-foil

FX 62-K-153/20

FX 62-K-153/20