Saturday, August 25, 2007

Composite F3B Glider Building group

At the beginning of 2007 I started a building group at my house on the West Rand to provide people with the opportunity to build the all composite F3B Shongololo Glider. (Designed by Craig Goodrum.) The response has been overwhelming with places booked into next year already. It seems that there is a big demand for F3B gliders.
Because imported model are expensive, with the cheapest being around R6000.00, many people that would like an F3B model simple cannot afford them. So having the opportunity to build your own at R2500.00 is very attractive. The Shongololo is a very good design, with lovely lines and smooth flying characteristics. Although the wing profile isn't as thin as the modern F3B gliders of today it is still competitive enough to use in the F3B League that will be running next year. (You can read more about this in earlier post on this Blog)

There is nothing new about building groups. This article is just to provide you with an idea of how it works. Basically there are 4 people involved, 3 working for 10 consecutive sessions, plus myself making up the 4th person. Four people building, is essential, as each will work on one wing panel. This facilitates a quick turnaround and because of it a model can be completed every 3rd week. The group meets once a week in the evenings from 18h00 until around 22h00 (4 hours). Sometimes this does extend depending on what we are busy with or how much fun we are having at the time. There have been evenings when I get into bed after midnight.
Each model takes only three sessions to complete and by the forth, everything is done and the persons whose model it is can take his components and bid us farewell so we can start the next model. There is an overlap on the 4th evening. Sounds complicated, but it isn't really! See table below.

When someone joins the group he will first be helping to build two other peoples models while gaining experience in the techniques of composite building. Because we build the wings first they are ready for de-molding by the third session. This gives me a week to clean up the molds and prepare them for the following session. There is some homework to be done before a person can start his model. The wing skins are a sandwich construction and the Herrex used in this has to be cut and sanded at home by the person whose model will be built. Templates and instruction are provided. Each session is divided into different tasks as per below.

Week 1 - Lay up wing skins & bag them. Make joiner box.
Week 2 - Lay up the first layers of the Fuselage. Join wings. Lay up stab skins & bag them.
Week 3 - Lay up carbon tows and joining layer of fuselage. Insert sheer web and joiner tubes and join the stab. Lay up canopy, servo tray & make wing joiner. Join fuselage. De-mould wing.
Week 4 & 1 - De-mould Fuselage, Stabilizer, Canopy, Servo Tray and Wing Joiner. Start new model. See 1 above.

This building group was started on the 14 February 2007 and in 6 months we have been able to produced 8 Shongololo’s.
The evenings are very relaxed and those that have built models so far have enjoyed the experience tremendously. All report that the 10 weeks goes by very quickly and they come away with a new understanding and experience on how to build composite models, plus of course, there very own model which they have built with their own hands. This, on its own gives one a great sense of achievement. Not only do you own a lovely model, but you have made it yourself!
To help, I also offer assistance on Saturdays with the little fiddly bits, like the hinging, servo mounting, wiring etc. Basically fitting out of the model and getting it ready to fly.

Below is the photo gallery of the models that have been produced in this building group to date.

01 Tony

02 Hannes

03 Gordon

04 Heinrich

05 Henk

06 Mark

07 Robert

08 Len

As mentioned earlier, the cost per glider is around R2500.00 each. This model is ideal for someone entering into F3B for the first time. Strong and robust and at a price that is unbeatable. If you’re not interested in F3B or competitive flying, it’s also a great general purpose thermal glider, with clean crisp responses and yet docile enough for anyone wanting a full house modern glider to just enjoy on a Sunday’s social flying.

The wing lay-up is a Hybrid, Carbon/Kevlar skin as can be seen in the photo on the left, where the wing is painted with a clear coat so the hybrid cloth is visible underneath. (Click on the image to get the bigger picture) The dark strip is the carbon spar-cap. Made up of 50 x 12K carbon tows. The hinges for the flaps and ailerons are live. In other words the Kevlar strands in the skin lay-up acts as the hinge.

The fuselage is Glass and Kevlar with Carbon reinforcing. This model has a cruciform tail with all flying stabilizer. The aluminum joiner tube is built into the stabilizer when the molds are closed. The fuselage is one piece with a canopy and a carbon servo tray is provided as well as carbon end ribs. The wing joiner is a hollow core unidirectional rectangle carbon rod.

Because of the way the group is structure, anyone can build one of these fancy composite models. You don’t need any special skills as there is plenty of help and guidance during the building process. All the specialized equipment and materials are provided for you. All you do is come and build.

So if you would like a Shongololo and you would like to get involved with the building of your very own F3B glider, please contact me on 083 254 1809 or email me at . Book your place today.
Evan Shaw.

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