shepeiro Posted January 29 Share Posted January 29 What’s the weight difference between the balsa spars with tow and just going for a square section carbon tube? Quote Link to comment Share on other sites More sharing options...
David Davis 2 Posted January 30 Share Posted January 30 10 hours ago, shepeiro said: What’s the weight difference between the balsa spars with tow and just going for a square section carbon tube? Dunno. Too late now anyway. Square section tube would have been an option. I have covered the leading edge in 1/16" (1.5 mm) balsa which has produced a very rigid wing which will not bend in the pylon race though perhaps its a bit heavy. I still need to build the tips and to add the cap strips. 1 Quote Link to comment Share on other sites More sharing options...
David Davis Posted January 30 Author Share Posted January 30 Talking of using carbon fibre in the wing structure of Barons, at the 2023 event there was a beautifully built Baron finished in transparent orange film so you could see the structure through the covering. The builder had made extensive use of carbon fibre rod or tube throughout the structure. However, when the model took off it was dangerously unstable and continued to perform all sorts of uncontrolled gyrations mostly over the crowd while drifting downwind. Eventually it crashed, fortunately without injuring anybody. I suspect that the centre of gravity was too far to the rear and perhaps the model had not been flown before in which case it's not good practice to fly a model for the first time in the heat of a competition. If the pilot was a member of a club, I'm surprised that no-one had advised him about the necessity of having the cg somewhere close to the recommended position. Perhaps the pilot was inexperienced and/or incompetent but I was very concerned at the time because quite a crowd had gathered behind the safety fence to watch the flying. Now I'm no Wolfgang Matt but I am reasonably competent. Mind you, the standard of piloting at La Coupe never ceases to amaze me, it varies from the experts who fly with metronomic precision to the downright dangerous. Fortunately the second category usually crash in the first round, so far without hurting anybody. Quote Link to comment Share on other sites More sharing options...
David Davis Posted February 1 Author Share Posted February 1 I have almost finished the Baron's new wing. It is very rigid and sure not to flex in the high G turns of the pylon race. It just requires the hard points for the dummy wing warping wires and a little more sheeting to be fitted as well as some filling and sanding, but Boris the pilot has not yet reported for duty. He has twenty-four hours to turn up otherwise he'll be replaced by an eager volunteer! Quote Link to comment Share on other sites More sharing options...
David Davis Posted February 3 Author Share Posted February 3 Boris reported at breakfast time this morning. He was full of tales of derring do whilst flying F16s over Ukraine. The Ukrainian Government has given him extended leave to fly in La Coupe Des Barons. However, he has lost his machine gun. I have sent a report up to the Wing Commander and given him the job of supervising the final stages of the construction of his aircraft's new wing. He will report to the Tall Fellah pictured on the right below, who would have flown in La Coupe if Boris had not returned. Picture of Boris in his aircraft shortly before the 2023 Coupe below. He crashed in practice and the Englishman had to fly. Quote Link to comment Share on other sites More sharing options...
David Davis Posted February 4 Author Share Posted February 4 Boris's wing is finished all but a little making good. It's very rigid. Quote Link to comment Share on other sites More sharing options...
David Davis Posted February 6 Author Share Posted February 6 I needed four sheets of 1/16" (1.5mm) balsa to cover the leading edges of the wing. Unfortunately I had none in stock so I bought some from the club. Each sheet was marked with the Solarbo logo. Unfortunately this wood proved to be rather brittle and I put my thumb through the wood when handling it. If you look closely at the last picture you'll see where I have repaired the sheeting with an off-cut near the centre section. This afternoon, while covering the port wing I did it again further out on the span. I have not seen Solarbo balsa wood for at least sixty years! Does anyone know whether balsa wood becomes more brittle as it ages? Quote Link to comment Share on other sites More sharing options...
Phil Green Posted February 6 Share Posted February 6 Quite a few of my models are old. One of my favourite nostalgia models is the Veron Impala, I have a few that range up to 50 years old. I would say balsa definitely does go brittle with extreme age, especially if the wood was chosen for lightness when first built 😉 2 Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted February 6 Share Posted February 6 53 minutes ago, David Davis said: I needed four sheets of 1/16" (1.5mm) balsa to cover the leading edges of the wing. Unfortunately I had none in stock so I bought some from the club. Each sheet was marked with the Solarbo logo. Unfortunately this wood proved to be rather brittle and I put my thumb through the wood when handling it. If you look closely at the last picture you'll see where I have repaired the sheeting with an off-cut near the centre section. This afternoon, while covering the port wing I did it again further out on the span. I have not seen Solarbo balsa wood for at least sixty years! Does anyone know whether balsa wood becomes more brittle as it ages? A good old name from the past - do you recall the Solarbo balsa bundles that were a whole week's pocket money of 2/6d or 12 1/2p in'new' money? The small town where we lived in the 60's had a toy and model shop that didn't sell balsa, but the fishing tackle shop did sell the Solarbo balsa bundles. Maybe for making floats? Always making chuck gliders and bits and pieces with them. IIRC, Solarbo were absorbed by one of the large distributors many years ago and then simply faded away. Yes, in my experience balsa deteriorates with age but mainly, I think, influenced by how it's stored. I have wood that's over twenty five years old and in excellent condition, but has been stored in an unused bedroom which neither gets hot or cold and certainly never damp. Garages and lofts used for balsa storage usually ruins it very quickly. 1 Quote Link to comment Share on other sites More sharing options...
Tom Gaskin 1 Posted February 6 Share Posted February 6 Solarbo 'morphed' into Amerang, who then iirc, bought Ripmax. Tom 1 Quote Link to comment Share on other sites More sharing options...
Cuban8 Posted February 7 Share Posted February 7 I seem to recall another old brand of Balsa that was called 'Premier' - had a blue stamped on logo if memory serves. Wonder who they were and what happened to them? Quote Link to comment Share on other sites More sharing options...
David Davis Posted February 13 Author Share Posted February 13 I finished covering the wing yesterday, I still have to fit the dummy wing warping wires and the Lewis gun. I took a leaf out of the RAF's 1940 playbook by covering the underside of the port wing in black film and the underside of the starboard wing in white! I had three flights with the British Baron yesterday with no issues. I'll decide which one to take to La Coupe once I've found out which is the best flyer. Quote Link to comment Share on other sites More sharing options...
David Davis Posted February 17 Author Share Posted February 17 (edited) I flew both Boris and Bertie this afternoon. These are my Ukrainian and British Barons respectively. It was the first outing for Boris's new wing. Both models flew well but I found that the Ukrainian model turned far more easily to the right than to the left. I brought it into land to discover that a joint had failed in the built up rudder in flight. I will repair it and reinforce the joint with thin plywood. The Ukrainian one was more easily visible owing the large areas of flourescent yellow and orange. I need to buy some Ukrainian roundels but money is a bit tight at the moment. Edited February 17 by David Davis Quote Link to comment Share on other sites More sharing options...
John Wagg Posted February 17 Share Posted February 17 Could you make some out of Solarfilm ? Yellow and Blue circles. https://commons.wikimedia.org/wiki/File:Roundel_of_Ukraine.svg Quote Link to comment Share on other sites More sharing options...
David Davis Posted February 18 Author Share Posted February 18 If I were to cut out a yellow and a blue circle from Solarfilm, using a blade in a compass, how would I attach them to the exising covering without using heat? I expect that the extra heat from the iron would distort the existing covering. Quote Link to comment Share on other sites More sharing options...
john davidson 1 Posted February 18 Share Posted February 18 glue such as por? Quote Link to comment Share on other sites More sharing options...
John Wagg Posted February 18 Share Posted February 18 2 hours ago, David Davis said: If I were to cut out a yellow and a blue circle from Solarfilm, using a blade in a compass, how would I attach them to the existing covering without using heat? I expect that the extra heat from the iron would distort the existing covering. Sorry, I haven't done Solarfilm roundels but have done stars. Probably a lot easier but did use heat and an iron. On my Morane I painted the roundels following Cliff Harvey's method :- https://www.youtube.com/watch?v=lnVcT90G2ls I didn't have Frog tape so used electricians tape cut into strips. I used acrylic paints from a local shop which are quite cheap but did a good job. https://www.theworks.co.uk/p/acrylic-paint/crawford-and-black-yellow-acrylic-paint-200ml/5052089334250.html (Other makes available but not sure about availability in France.) 1 Quote Link to comment Share on other sites More sharing options...
John Wagg Posted February 18 Share Posted February 18 P.S. To late for an edit. - The side roundels I cheated and bought stick on ones from Ebay. The rudder stripes I did paint but they were easy. Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted February 18 Share Posted February 18 Compass and tape for me,,, Quote Link to comment Share on other sites More sharing options...
David Davis Posted March 7 Author Share Posted March 7 (edited) While practising for La Coupe Des Barons last week one of the wheels fell off and disappeared into the plough. I managed to get the model down onto our 10 metre wide tarmac runway. Picture of your humble servant and the Ukrainian Baron below. Note the very small wheels. Given the cost of WW1 replica wheels I'm planning to make my own out of balsa and ply with a neoprene tyre. Any tips? Edited March 7 by David Davis Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted March 7 Share Posted March 7 I use these,, Quote Link to comment Share on other sites More sharing options...
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