David Davis Posted November 12, 2024 Share Posted November 12, 2024 Good Day Gentlemen, I am starting to think about about the Coupe Des Barons 2025. I currently have two Barons, one finished in British markings which I've called Bertie, and the other, Boris, in Ukrainian colours. Boris is slightly easier to fly but I broke the wing in practice earlier in the year so will need to build a new one. I propose to build one with a D section leading edge and depron ribs as I did for Bertie last year. This will be lighter than the stock wing but at least as strong. I toyed with the idea of building a completely new Baron, covering it doculam and tissue and powering it by a Laser 50 which I bought from A Plane Olde Bargain at a very reasonable price earlier in the year. I thought that it would be ubercool to have a British pilot, flying a model powered by a British engine with RAF roundels on it in the competition. However, other committments may get in the way so I'll concentrate on repairing Boris's wing first. Another expatriate Englishman called Mike who also lives in La Belle France intends to enter the competition next year with a model powered by a PAW 35 diesel! If he does enter we'll be able to pit for each other. Which leads me on to engine choice. I'm actually spoiled for choice. I have become well known for competing with a four-stroke powered model, indeed I have taken to giving a prize to the leading pilot who uses a fourstroke engine in the competition, I have two OS 48 Surpasses, a Magnum 52, a Thunder Tiger 54 when it comes back from the menders and an OS 52 which I've built up from bits after the model crashed. It has exposed pushrods and rockers but it might look quite quirky! Then of course there's always the Laser 50 but I'll be giving my opponents something of an advantage if I were to use that because it is 100 grammes or 3.5 ounces heavier than an OS 52Surpass nd I doubt that it's as powerful. Decisions, decisions. What does anybody else think? Last year's event was cancelled owing to an inclement weather forecast but for those unfamiliar with La Coupe, have a look at this: https://www.youtube.com/watch?v=JuMm24PTZ_Y 1 Quote Link to comment Share on other sites More sharing options...
ronron Posted December 9, 2024 Share Posted December 9, 2024 Hi David, Os 52 is better, but it is not as fast as mine electric 4238 😁 Quote Link to comment Share on other sites More sharing options...
David Davis Posted December 10, 2024 Author Share Posted December 10, 2024 10 hours ago, ronron said: Hi David, Os 52 is better, but it is not as fast as mine electric 4238 😁 Quite so Ron but I won the four-stroke class in 2021 and since 2020 I have always given a prize to the leading pilot who uses a four-stroke so I'm committed to flying a four-stroke in the competition. I don't see a competition number on your model. Will you be entering la Coupe Des Barons next year? If so, feel free to introduce yourself at Ste Marie d'Alloix. I speak passable French. Quote Link to comment Share on other sites More sharing options...
ronron Posted December 12, 2024 Share Posted December 12, 2024 hi David, i will see you there, my number is 230 our club is at Les Valayans https://amc-pernes-lesvalayans.com/fr/ Quote Link to comment Share on other sites More sharing options...
David Davis Posted December 14, 2024 Author Share Posted December 14, 2024 My clubmates are too cowardly to venture down the La Coupe but I may be able to persuade one of them to come down with me. If not will you stand in as my "mechanic?" Quote Link to comment Share on other sites More sharing options...
ronron Posted December 15, 2024 Share Posted December 15, 2024 yes of course ! Quote Link to comment Share on other sites More sharing options...
David Davis Posted December 16, 2024 Author Share Posted December 16, 2024 Merci beaucoup! Quote Link to comment Share on other sites More sharing options...
David Davis Posted December 23, 2024 Author Share Posted December 23, 2024 OK, one for the engineers among you. I am about to start building a new wing for Boris Baron. I will use a classic three-spar arrangement with two 1/4" balsa spars one above the other at the widest point of the wing rib and another halfway between these spars and the trailing edge. I will use depron for the wing ribs as I did for for Bertie Baron last year. Picture below. I'm considering using carbon fibre tow, a narow strip of carbon fibre cloth, to strengthen the lower spar. My question is, should I also use cabon fibre tow on the upper spar as well? Both spars will be tied together with 1/16" inter-spar webbing, grain vertical. Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted December 23, 2024 Share Posted December 23, 2024 (edited) It depends if it's a baron with its 4cc ic motor or a silly .60 powered one !, I forgot to add what are you using to cover it ?, my OS 28fs powered one has 4mm x 4mm stringers and silk covered, which of course really strengthens it up. Edited December 23, 2024 by Paul De Tourtoulon Quote Link to comment Share on other sites More sharing options...
Bruce Collinson Posted December 23, 2024 Share Posted December 23, 2024 Won’t it be in compression, unless inverted? Does it perform in compression? I thought its overarching property was tensile strength. Maybe will only add minimal weight though. Will the shear webs transfer the loads across both the spars? Will it degrade the slight flexibility of the balsa spars? Quote Link to comment Share on other sites More sharing options...
David Davis Posted December 23, 2024 Author Share Posted December 23, 2024 51 minutes ago, Paul De Tourtoulon said: It depends if it's a baron with its 4cc ic motor or a silly .60 powered one !, I forgot to add what are you using to cover it ?, my OS 28fs powered one has 4mm x 4mm stringers and silk covered, which of course really strengthens it up. It will be powered by an OS 48FS or 52FS and it will be covered in film like the pictures below. 2 minutes ago, Bruce Collinson said: Won’t it be in compression, unless inverted? Does it perform in compression? I thought its overarching property was tensile strength. Maybe will only add minimal weight though. Will the shear webs transfer the loads across both the spars? Will it degrade the slight flexibility of the balsa spars? The reason I'm thinking of using carbon fibre on the lower spar is to make the wing more rigid. One of the four flying rounds of the competition is the pylon race where you just go as fast as possible for five minutes. In practice I think that the wing on the British Baron is flexing in the turns but it could just be my imagination. Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted December 23, 2024 Share Posted December 23, 2024 I am old fashioned, I would stick to the original plan, but if you want it to go faster, thin down the wing section. Quote Link to comment Share on other sites More sharing options...
Martin Dance 1 Posted December 23, 2024 Share Posted December 23, 2024 I don't know whether adding a second piece of carbon fire to the spar structure would be beneficial. How about adding some carbon fibre rod to the leadig edge to strengthen it for the deliberate collisions with your balsa stick round and the inevitable collisions with the limbo poles? Not to mention hitting each other. 1 Quote Link to comment Share on other sites More sharing options...
David Davis Posted December 23, 2024 Author Share Posted December 23, 2024 3 hours ago, Paul De Tourtoulon said: I am old fashioned, I would stick to the original plan, but if you want it to go faster, thin down the wing section. The original wing is unnecessarily complicated, see the pictures below. My version is lighter but stronger. Having said that, I think I've put the carbon fibre tow on the wrong side of the spar, it should have been on the underside. Maybe that's why the wing appears to flex in high speed flight! 57 minutes ago, Martin Dance 1 said: I don't know whether adding a second piece of carbon fire to the spar structure would be beneficial. How about adding some carbon fibre rod to the leadig edge to strengthen it for the deliberate collisions with your balsa stick round and the inevitable collisions with the limbo poles? Not to mention hitting each other. The leading edge of Bertie's 2024 wing is a fibre glass tube. Boris's new wing will be the same. Quote Link to comment Share on other sites More sharing options...
Don Fry Posted December 23, 2024 Share Posted December 23, 2024 That thing, 52 fs motor without a pipe. Wet paper would do it. As a first guess, loose weight. Spars, foam, carbon laminate to and bottom, ribs foam, fus, foam, bits of balsa to stiffen it. It’s got to hold the bits at the right angles, but as the weight comes off, the stresses needed to do it become smaller. That allows the incidence angles to become smaller, reducing stress. How light can it be made. i don’t think reinforcing it so it survives mid airs is a winning solution. Fat blokes never win races. Quote Link to comment Share on other sites More sharing options...
David Davis Posted December 23, 2024 Author Share Posted December 23, 2024 Don, what you say is quite correct but I only plan to build a new wing for the Ukrainian Baron, the fuselage and tail surfaces are sound. The British Baron is in serviceable condition, the idea is to get the other one into flying condition as a spare in case I crash one in practice. I do not have the time to build another Baron fuselage because I have too many other model aeroplane commitments. Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted December 25, 2024 Share Posted December 25, 2024 (edited) As Don says, fat people win races, I won a few when pylon racing, arf plane std servos and an ordinary .45, its good flying by the pilot that can make the difference. Not forgetting the caller. Edited December 25, 2024 by Paul De Tourtoulon Quote Link to comment Share on other sites More sharing options...
Don Fry Posted December 25, 2024 Share Posted December 25, 2024 47 minutes ago, Paul De Tourtoulon said: As Don says, fat people win races, I won a few when pylon racing, arf plane std servos and an ordinary .45, its good flying by the pilot that can make the difference. Not forgetting the caller. Remember the brave pitman, refuel, start, away, in under 10 seconds. Seriously David, small movements, flight path smooth as a blonds bottom, and 15 g HV servoes, mini rx, 2 cell 400 lipo (300?), and look to loose half kilo plus in airframe weight. Weight needs lift to stay up, lift requires drag, can’t argue with physics. Quote Link to comment Share on other sites More sharing options...
David Davis Posted January 1 Author Share Posted January 1 Happy New Year everybody and thank you for the advice Don. As things stand I have one Baron ready to fly and another which needs a new wing. Watch this space. The competition will take place on 21st June this year at Ste Marie d'Alloix between Chambery and Grenoble. I have already registered my interest. If anyone else wants to enter the competition you may apply here: https://saffiotipatrick.wixsite.com/vl38/les-barons. Click on "Inscriptions." English residents may stumble at the bit which asks for your FFAM (Federation Francaise d'Aeromodellisme) number. If you find that it's a problem, please let me know and I'll have a word with the organisers. If you need me to translate the rules, please let me know. Quote Link to comment Share on other sites More sharing options...
Tom Gaskin 1 Posted January 1 Share Posted January 1 David, Add webbing to both sides of the mainspars to really stiffen things up without adding undue weight. Tom 1 Quote Link to comment Share on other sites More sharing options...
David Davis Posted January 8 Author Share Posted January 8 I have started the construction of the new wing for my UKrainian Baron using depron for the wing ribs. I did something similat last year when I built a new wing for my other Baron. With that wing I used moderately hard balsa for both the root rib and the tip rib but is that necessary or even advisable? Pictures of the completed wing and the wing under construction below. Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted January 8 Share Posted January 8 Still using Model Technics fuel ?, which one. Quote Link to comment Share on other sites More sharing options...
David Davis Posted January 8 Author Share Posted January 8 Laser low oil in my modern Lasers. Quote Link to comment Share on other sites More sharing options...
David Davis Posted January 13 Author Share Posted January 13 I've started the construction of a new wing for my Ukrainian Baron using carbon fibre tow under both of the 1/4" (6mm sq) balsa spars, depron wing ribs and a carbon fibre tube leading edge. This year I have built the wing over a Super 60 plan using that model's rib spacing. Still a lot to do of course. Quote Link to comment Share on other sites More sharing options...
David Davis Posted January 28 Author Share Posted January 28 The basic structure of the wing is complete. I have used carbon fibre tow to reinforce the balsa main spars and I have boxed them in with interspar webbing. The wing ribs are from depron and the leading edge is carbon fibre tube. I have recycled the centre section from the Baron which crashed and have used Gorilla Glue, De Luxe Materials Super Phatic and UHU Por as adhesives. There's stil a bit to go of course, sheeting the leading edge for example and building the Baron's characteristic raked tips. 1 Quote Link to comment Share on other sites More sharing options...
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