Friday 27th January - Multi-motor Electric Aircraft by Mick Prior
Mick gave us a very interesting talk, starting with a little history about his modelling career, which started at around the age of 10, missed a few years when cars, beer and girls came along, and then re-started in the 70s. Mick enjoys building as much as flying - if not more so - and encouraged anyone who hadn't tried building their own model to "have a go". His most important modelling tool is a pair of scales - and this led into his topic of weight versus strength. Mick gave many tips including; selection of balsa (he had brought along 3 sheets of 1/8 x 4 x 36, which ranged in weight from approx. 25gms to 65gms - if you used 10 of the lighter sheets in a model, you could save close on a pound in weight (sorry about the mixture of imperial and metric !). He compared the all-up weight of laser-cut ARTF models with similar-sized carefully-self-built models, and showed that equivalent weights can be achieved, but the self-built model can have greater strength. Other tips included using Lite-Ply instead of Birch Ply, smaller/lighter Servos where only a low torque was required, cutting off excess length from metal bolts, shifting Batteries and Radio Gear forward or backward to avoid having to add nose or tail weight to achieve a correct CofG, and so on. He also suggested that steerable nosewheels are perhaps not always necessary - they tend to require heavy-duty, and therefore heavy, servos to actuate them, when simple rudder control is probably just as effective, and also suggested that sprung undercarriages are useful in helping to avoid the shocks of a heavy landing. Mick had brought along 4 aircraft - a 72" Lancaster from the Tony Nijhuis / SLEC kit, a 50" Short Skyvan from an old RCM&E plan, a beautifully finished (in Chrome Yellow Profilm) Britten Norman Trislander, and a finished-but-not-covered Miles Aerovan. Mention was made of many different combinations of Motor / Speed Controller / Battery, but one or two important points emerged; leads between Battery and Speed Controller should be kept as short as reasonably possible, with any unavoidable lead length being between Speed Controller and Motor; a single Battery should be used to provide power to a pair of Motors, e.g. both inboard motors, or both outboard motors, so that, in the event of a battery failure, an assymetric situation, which could induce a left/right imbalance, and therefore possibly a powered spin, could not occur. All in all, I found this a most informative and interesting talk - thanks Mick ! Pictured below, left to right are: Lancaster, Miles Aerovan, Britten Norman Trislander, Mick, and Short Skyvan.
Friday 20th January - Vac Forming by Denis Pitcher
Awaiting report. I am sure this was good, as I have attended previous talks/demonstrations by Denis on this subject. Can anybody send me something please ?
Friday 13th January - Annual Dinner and Prizegiving for 2011
Was held at the Billing Mill Pub Restaurant, with approx. 50 guests - a really good turnout. We had a room to ourselves, and food was cheap and cheerful. John Fairs organised an excellent Quiz, which kept people busy during the early part of the evening. A super Raffle was organised by John Cross and Dave Parker, with some really great prizes (and I won one of them!). Our President Brian Baker, ably assisted by Bernard Schooley, presented the Trophies and Certificates for the Competition Winners and Runners-up (too many to mention here), and a Trophy for our overall winner, Graham Mills. Dick King was presented with his BMFA "A" Certificate, gained earlier in the year. Perhaps the highlight of the evening was the Magician, wowing everybody with close-up magic at the tables whilst we were eating, rounded off by a full audience show in which some of the guests were invited to take part.
Friday 6th January - Allan Ballard and Ladbroke Hobbies colleagues demonstrating the DS4 Petrol 4-stroke engine
Allan gave us an interesting talk about the DS4, its origins, development, manufacture and operation, accompanied by actual running of a sample engine in the backyard of the Centre. The DS4 is a hand made 50cc single cylinder design, fitted with a Tillotson carb, which seems to suit the characteristics of this engine better than the usual Walbro carb. It is slow-revving, and high torque, and therefore suits larger diameter props. Some versions of the engine have been fitted with Fuel Injection, particularly the 120cc version which can operate at 50,000 feet, and sub-zero temperatures (they also make engines for military UAVs). Allan also showed pictures of components for both a horizontally-opposed twin, and also a vee-twin.
Ladbroke's display pilot, Clive Grisold, then gave us a very enthusiastic talk about flying models with DS4 power, and how models that one might expect to be difficult to fly, were in fact easy to fly, due in part at least to the unique characteristics of this engine.
During and after the talk we were treated to several videos of the DS powered aircraft in flight, including a 1/3 scale Sopwith Pup fitted with a 120cc variant, and a hilarious video of a landing by a full-size aerobatic plane which lost half its wing in flight!
You can see some of the videos, engine pictures, and much more, on their website www.ladbrokehobbies.co.uk.