Hobby shops with specialised equipment

I had a hobby shop run the other day and would recommend the following for electrical and small parts and support.

1. Dion Liebenberg in Benoni (Sarel CIlliers 105, Reinfield, 0825701053. He is the SA Graupner agent (Look at www.graupner.com) and can help with many small parts like clevis, special horns, carbon push rods, etc. (German) and electric setups.

2. Mad Models (www.madmodels.co.za) (Jonathan) the best hobby shop I know of for electric models but also have many other parts and materials for building etc. From the Pomona offramp close to Kemptonpark.

3. Radio Control Repair Centre (Dave Armatage) for any custom battery packs, JR equipment and some small parts like servo plugs and wire. Garsfontein, Pta.

4. In Cape Town the only shop I will recommend is the Hobby Warehouse who is a true hobby shop. Sad to say Clowns is not what it was.

Most of the other shops are toyshops nowadays, but if you know your prices you may find a bargain.

Cheers Gert

Choosing a model Glider (Part 2)

The normal hobby shop does not have experience in advising you on gliders or stock models that can be used successful for gliding competitions. There are how ever a few knowledgeable shops and fellow glider pilots who can assist. The trusty old Gentle Lady has been used by many to learn the basics of RC aero modelling. I have seen a few available as ARF kits. Another model is the Spirit which comes in 2m RES (Rudder Elevator Spoiler) or aileron versions. Another alternative is to scratch build a model from plans. There is many plans available for sale from RCM, Traplet, etc. or freeware on the internet. The construction methods can vary from balsa and film covered models, foam and veneer to composite materials (consult a glider pilot before choosing a plan). A combination of these construction methods is normally used to achieve the best results nowadays. There are some gliders available from the local cottage industry which are built by fellow glider pilots or building groups. The Thotsi is one such example of a composite 2m glider (Foam /fibre glass wings and Fibreglass fuz) which takes most of the local competition places. Some kits are available from over seas which are worth exploring. (try ArtHobby.com)

There are many classes of gliders each with its own purpose or flying conditions. On the thermal side you will find the small 1m to 1.5m wingspan models which is launched by hand (Discuss side arm or javelin style). The larger 2m span models would be a wise choice to start with. These models can be launched by bungee or winch. The construction of the model should be carefully designed for the method of launching. In South Africa we have the RES/100 class which allow you to use larger wingspan models. These models can be constructed relatively inexpensive and can compete on a fair basis with the open class models. To be able to fly well in all conditions (wind or calm) you may have to chose a model which has a better wing section. This is not always possible with built-up models (balsa wing ribs). This is how model glides have developed from the 70’s where mostly built-up models were available up to today where the most competitive model is made of composite materials which have been moulded. The composite models are mostly imported. There is a few local designs available like the Eish!, Shongololo, Makulu and Inkwasi which all fly very well and is about half the price of the imported models. Open class gliders with full house control can be scratch built from plans as I and many others have done (even up to World Cup standard pilots do this). These models is just as competitive if built correctly and cost a fraction of the imported models, but come at a price on time.

Depending on your proficiency and available budget you will be able to find a model which suits you best. Ask for help if you are interested to take the step.

Introduction to Gliding (part1)

You may ask yourself the question why would someone be interested in flying a glider? Probably every glider pilot will have his own story, but here is mine. I started flying RC with a Gentle Lady (still have it!) and launched it with a bungee. The friend who taught me how to fly RC was a full-size glider pilot himself except for being an exceptional RC pilot. So I was lucky to learn from him to read the air and be able to catch thermals. I built several power models after that, but had not have much luck in learning to fly them and the damage was always very expensive. At that time I started to follow the SA glider community news. The Goodrums produced a kit of a 2m glider which had better performance than the GL I was flying and I acquired one. This model had a fibreglass fuz and veneer covered foam wings but still only Rudder/Elevator control. I also built several larger gliders like a Sagita (2,5m) and others with basic wood building material from plans. By this time I discovered the slope at Volksrust and built many models which could be flown off the slope. Slope flying is still one of the most amazing experiences for me. Flying at the slope also improved my flying skills. Back to Thermal flying, at some stage I visited one of the Highveld Thermal league competitions as a spectator and saw this is what I want to do. The gliders were mostly moulded high-tech models. I started taking part in an entry level thermal competition for 2m gliders which was called G2K. This helped me improve by leaps in air reading and precision flying. As with any competitive environment, I soon realised I need a better model to do better. To improve my model I had to understand some aerodynamic principals and lots of time was spent on research and discussions on the internet. I also took part in the National postal competition which can be done at your own club and is flown 4 times per year. Gliding (slope and thermal) kept me busy for the biggest part of the year or is it all the time I had available.

I later built a Bubble Dancer from freeware plans designed by Dr Mark Drela which was my first high-tech glider (but still only Rudder Elevator Spoiler) for competitions. I used this model to enter in the Highveldt Thermal league successfully for a few years and Nationals. My first ”full-house” glider was also a scratch built of the Supra designed by Dr Mark Drela. I am currently busy to build (very slowly) another Supra and I now own a moulded Supra which was manufactured in Eastern Europe. I have built many other gliders from, discus hand launch, Scale, electric, to many to mention.

I believe one of the aspects that draw me to gliders is the technical aspect in the design and construction of the models. Model gliders are at this stage at the forefront of development in RC. The state of art glider is manufactured in negative moulds from composite materials like Fibre glass, Kevlar and Carbon fibre. The empty model cost in the area of R10000-R15000. The wing profiles have been developed and tested in wind tunnels. The construction techniques have improved drastically in the past decade alone. As an example, the wing thickness of a modern glider at the root is about 20mm for a cord of 250mm and span of 3,4m (Supra). The wing spar which carry most of the load during launch have to be designed to fit in this thin wing. The pull load on the wing is in the order of 50-80 kg during a launch. Another aspect which I find interesting is the programming and set up of the models. With 4 servos in the wing and up to 5 flight modes (Launch, Speed, Thermal, Cruse and Land) which are used to change the camber of the wing and the modern computer radio you are able to take full advantage of all the aerodynamics for better control of your flight path. The best part however is the gliding community. If you are flying a GL or a state of the art model, all are welcome to fly and test your abilities even if it is only to measure your own improvement. It is mostly like minded people who like to share their knowledge and passion for models. I have made so many glider friends over the years due to the fact that they made time to help me, and it taught me to do the same. As you saw from my story above, it is not necessary to have the best and latest equipment in order to enjoy and take part in model gliding.

Cheers

Gert

Sunday flying.

Well, the weather on Sunday was absolutely beautiful for flying, and quite a lot of the guys turned up at the field to take advantage of the fine day. Henk se Edge 540. -- from hyper7pro - (?) My Skybolt coming in for a "touch and go". -- from hyper7pro - (?)

-- from hyper7pro - (?) Marius Burger built this absolutely beautiful little plane. The trim flight was a little rough because of elevator over sensitivity. After landing, he cut about 1 cm off the elevator, and the next three flights was awesome! The little engine runs full blast until the tank is empty, and then you do a few slow graceful gliding circuits, and then the landing. This is probably the last post for 2007, so seasons greetings, and a prosperous 2008 to everybody! Last but certainly not least, I would like to congratulate Dirk and Juanita on the birth of their daughter.