David Ovenden Posted November 20, 2020 Author Share Posted November 20, 2020 Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted November 21, 2020 Author Share Posted November 21, 2020 Its getting cold in the workshop with no heating. This afternoon I did manage to construct one fuselage side frame before the chill got to my fingers. I know it would make sense to use a heater! The structure is 1/4 sq balsa and looks flimsy. It will eventually have formers added plus 32 stringers to give the correct bulbous look. In the meantime I am seriously contemplating adding some 1/8 x 1/4 diagonals between the uprights to give a bit more stability to the frames. Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted November 21, 2020 Author Share Posted November 21, 2020 Had a cup of tea. Warmed up and decided to add the bracing. It was only a few grams of balsa extra but should add some rigidity whilst joining the side frames and adding the stringers. Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted November 23, 2020 Author Share Posted November 23, 2020 Built the second fuselage side. So now time to join them and start fuselage construction. However, the plan shows multiple formers that attach to the basic box frame. They are all notched to take the (32) stringers. That's a lot of cutting and notching. My past experience of cutting out this type of former (KK scale rubber models) warns me that a) the balsa will spit between the notches and b) That the stringers won't line up when they sit in the pre-cut notches and will look "wonky". So to save time and balsa I am very tempted just to cut out a basic shape (smooth outline along the base point of the notches and then align the stringers as I glue them on. The downside is that the 1/8" x 3/8" stringers will have very little contact area to glue to. Effectively just a 1/8"sq area of contact with each former. Is that enough? Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted November 23, 2020 Share Posted November 23, 2020 It looks like a great project David but why put up with a cold workshop? I have one of these Chinese diesel heaters in my garage and it is so warm I don't want to leave it. Trouble is, the mice love it too! Quote Link to comment Share on other sites More sharing options...
Eric Robson Posted November 23, 2020 Share Posted November 23, 2020 You don't have to work out of the house David .Tell her indoors just who is the boss then ask her nicely if she minds you bringing it in for the winter. Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted November 23, 2020 Share Posted November 23, 2020 Posted by David Ovenden on 23/11/2020 11:59:43: The downside is that the 1/8" x 3/8" stringers will have very little contact area to glue to. Effectively just a 1/8"sq area of contact with each former. Is that enough? If you then fill in the missing former parts between the stringers you effectively restore the full joint strength, albeit with a tiny weight penalty for the extra glue used but with nice straight stringers. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted November 23, 2020 Share Posted November 23, 2020 I don't think it will be much of a problem with the 3mm stringers glued to smooth formers rather than cutting notches which aren't likely to be super accurately positioned to make the stringer straight. The stringers and ultimate covering will support each other and they aren't really stuctural. It'll look a lot better if the stringers are straight. If you're using 'tex covering them that's even truer. It's coming together very micely. Geoff Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted November 23, 2020 Author Share Posted November 23, 2020 Piers, Tempted by one of those diesel heaters. Did you have to buy a silencer as an extra? Geoff and Bob, Thanks for the feedback ideas. I'm going for the smooth contour formers. Can't be bothered to trace and try to cut out all those notches. I'm using Solartex (had lots in stock) so I need the stringers to look right. I also decided to build some simple "formers" to go in key locations rather than just rely on 1/4" sq balsa to join the sides. Should keep things square and more rigid during the construction phase. Edited By David Ovenden on 23/11/2020 21:54:52 Edited By David Ovenden on 23/11/2020 21:58:38 Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted November 23, 2020 Author Share Posted November 23, 2020 Found a source of free liteply at the supermarket! Fruit boxes had been thrown out and had some quite nice liteply sides and ends. I "rescued" some for non-critical small parts on the model. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted November 23, 2020 Share Posted November 23, 2020 That's useful to know, David. It would also be useful to know which variety of supermarket so I can 'visit' and 'rescure' a few bits of liteply (or poplar) for future use. When I was sailing 12'6" dinghies a club member used to use mahogany from packing cases for some of his builds. This was over 30 years ago so repurposing wood is not a new idea. Geoff Quote Link to comment Share on other sites More sharing options...
David P Williams Posted November 24, 2020 Share Posted November 24, 2020 Another silent watcher here too David. My next project when (if) the current one is off the bench is another biplane twin, a 1/6 DH89a Dragon Rapide, which is also an older, overengineered, one piece (96" wing plan, so I'm particularly interested in how your split detachable wing solution works out. The Rapide wing is really thin, only 15mm or so, so joiner arrangement will be 'interesting'. Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted November 24, 2020 Author Share Posted November 24, 2020 Geoff, boxes just were piled outside the local (independent) greengrocer shop. Its only one shop so little use to anyone. In any case, the boxes never seem to be the same. Nearly always they are made from thin MDF. But when I spotted these, I thought they might be useful Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted November 24, 2020 Author Share Posted November 24, 2020 Hi David, I had the plans for a 96" DH Dragon (not the rapide) but sold them on a while back as I decided to do the Condor - and one big twin biplane was enough for me! Good luck with your project. 15mm is not much depth to play with. But with a biplane, if the rigging is functional, it needed have massive joiners. I am lucky with the Condor that the wing is semi- symmetrical so there is a little more depth in the ribs to play with. Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted November 25, 2020 Author Share Posted November 25, 2020 I ended up making up 4 lightweight strip wood formers to help join the fuselage sides nice and square. Otherwise it was just relying on the 1/4sq crosspieces to hold it all true! Next is to cut out all the side and top former shapes and fit all those stringers. Sorry about the poor photo quality. Quote Link to comment Share on other sites More sharing options...
Eric Robson Posted November 25, 2020 Share Posted November 25, 2020 Going together nicely David , I built a 48" span Hurricane from my own drawings and made the formers plain just marking the position on the first and last. I then laid the stringers on and glued them in place it worked fine. Bobs suggestion would probably be better for yours due to the size, Edited By Eric Robson on 25/11/2020 20:04:54 Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted November 27, 2020 Author Share Posted November 27, 2020 Started to add stringers to the underside of the fuselage. I used a notched former at the wing seat but the rest were smooth. Seems to have worked fine. When everything is properly dried I can think whether the stringer/former joint need reinforcing. Currently I'm thinking it won't be necessary. Also started carving the tail seat blocks so I can sheet/plank the rear fuselage lower tail section. Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted December 1, 2020 Author Share Posted December 1, 2020 Progress been a bit slow. I have stripped 3 sheets of 1/8" balsa to make the many stringers that will be needed. Soldered up the connectors onto the ESC and motors and made some progress with cutting out the side/to formers. In the end I opted for a mix of notched and smooth. Notched at the both ends of a "run" and smooth in between. Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted December 5, 2020 Author Share Posted December 5, 2020 I am getting a little frustrated now because I really need to get on with building the wing centre sections so I can make progress on the fuselage. I need the lower wing centre section to line-up and finish the formers and stringers under the fuselage. And the top fuselage stringers can't go in until I've got the top wing centre section so I can fit and align the top wing structs that are bolted to 2 of the top fuselage formers. AND.. I can't build the wings until I have the carbon fibre wing tubes that align and are integral to the wing build. I have been waiting 4 weeks for HK to deliver them from the EU warehouse. So its not as if its a delay from the HK warehouse. In the meantime, I have finished off the underwing formers and components that support the undercarriage. I have also laminated some 3/16" "beams" that take the wing bolts but have to conform to the fuselage underside curve. I made a jig from a piece of old oak fence post and laminated 3 layers of ply to get the correct curvature. You can see that I have been able to use some upcycled wood from a "fruit crate" for a few parts. Fuselage section that will fit onto the lower wing centre section. (once I can get it built) The long beams will bolt the lower wing to the fuselage. They are fabricated from 3 layers of plywood. Wing bolts beam being laminated on fence post former! Edited By David Ovenden on 05/12/2020 13:10:41 Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted December 5, 2020 Author Share Posted December 5, 2020 Also couldn't resist a quick "play" to see how the tail assemblies look in situ. Quote Link to comment Share on other sites More sharing options...
Dwain Dibley. Posted December 5, 2020 Share Posted December 5, 2020 The obligatory "Dry fit" David, it has to be done Matey. D.D. Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted December 12, 2020 Author Share Posted December 12, 2020 Still no sign of the carbon wing tubes from HK so I ordered some more from another supplier. They arrived this morning, so I have managed to start the lower wing centre section. Hope to get the top sheeting on later. Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted December 12, 2020 Author Share Posted December 12, 2020 Top sheeting on. Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted December 14, 2020 Author Share Posted December 14, 2020 Wing tubes all epoxied in, spar webbing fitted, pull cords for motor wires done, and lower wing centre section sheeting completed. Next step is to trial fit to fuselage and build on lower formers, add stringers to the underbelly/ and add the wing mounting beams Edited By David Ovenden on 14/12/2020 16:04:45 Quote Link to comment Share on other sites More sharing options...
David Ovenden Posted December 14, 2020 Author Share Posted December 14, 2020 Duplicate deleted Edited By David Ovenden on 14/12/2020 20:53:35 Quote Link to comment Share on other sites More sharing options...
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