Martin & Sue HARDY

Dale, I absolutely believe your problem is caused by thermal expansion of the snake inner. Why do I say that? Last week during the hot weather my new Viscount was left in the sun upside down after being assembled while I flew other models. It was then placed in the pits ready to fly. Control checks prior to taxiing out showed the elevator movement which should have been 50% up and down was about 80% up 20% down The rudder was also out of alignment. The flight was cancelled and advice sought from the several very experienced modellers present. After investigations and tests the consensus was that the elevator and rudder snake inners had expanded in the heat. Most of us had used snakes for years on various models and this was the first any of us had seen such an extreme occurrence. The model was placed in the shade and left to cool off. As the model cooled off over a couple of hours the the control surfaces gradually returned to near normal positions. The snakes are just under 1m long, properly fitted and secured. The underside of the fuselage which was in full sun is dark blue in colour and the dark colour extends the whole length of the fuselage. Control surfaces have quite a large cord (scaled from the full size aircraft) with a relatively small angular movement required to give the required control. This probably amplified the effect of the expansion in the snake core. What to do about it? It was too large an error to deal with using trims, so short of regularly checking and resetting the transmitter settings on hot days a more permanent answer was required. This looked like involving replacing the snake core with a different material. Carbon rod was considered but would probably have been too stiff to follow the curvature of the fuselage - the reason for using snakes in the first place. The answer came in the form of Bowden cables sourced from Modelfixings, together with solder adapters for the ends. The cable and its sheath fitted easily inside the snake outer, with the sheath being cut to the length of the snake outer. It involved an afternoon of keyhole surgery to fit these into the model and the results seemed promising. The model was assembled at the patch again yesterday and left in the sun for several hours to warm up. There was no movement of elevator or rudder from their centre positions. Control checks were normal and the model was flown without incident or requiring any change of trim from earlier flights. Will I use this method again? Probably, if long snakes are the best solution for the model in question. Better to eliminate a possible problem rather than have to fix it later. Will I take extra care during pre-flight control checks - absolutely. I doubt that the model would have survived had I flown without spotting the problem.

Just found this! A flyer in my own right (although not as good as Martin!). The first female member of the first club we joined that gained an A Test in any medium (A SFE). So far as aware, still only female member of existing club. Slightly a 'fair weather' pilot, but enjoy the trips with the water models (Twotter, Sealand, Piaggio and large FunCub). Just need to get confidence to have a go. The twin engine models more easy to handle than the FunCub as they have differential throttles which helps with the taxying. I was the full size gliding 'crew chief' for a number of years, became quite adept at towing! Generally the trailer while Martin towed the caravan. HWMBO has Diamond C and over 2000 hours. He retired from full size in 2009 to go back to modelling. For 26 years, I owned the tail plane and release hook of the SHK - after all he couldn't fly without them! Mind you I am not the best of cooks, and hate shopping/shoes! Sue

Ian, I am the owner and builder of the Anson shown in the video. I also designed and built the retracts used. I have sent you a message with my e-mail, should you want pics or details I would be happy to help. Cheers