Simon Chaddock Posted July 21, 2017 Author Share Posted July 21, 2017 The wings glued in place. Tail booms next but I have not yet worked out how to make them! My intention is to build them as hollow stressed skin structures like the fuselage but such a construction may prove to be impractical. . Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted July 21, 2017 Share Posted July 21, 2017 You could forget the booms, with the ailerons set up as elevens and c of g in the right place, that would work as a tail-less job. (Almost certainly DH's original intention anyway, they chickened out after experience with the Swallow)! Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted July 22, 2017 Author Share Posted July 22, 2017 Constructing the booms is proving to be very slow going. Having looked at the 3 view for some time it seemed logical to have a fully planked front section and a rear section incorporating the fin. The front to be built up like the fuselage as half section over the plan and completed once lifted. More work in it than in the fuselage and a great beal more delicate. Suitably light at 7.2 g although i am not particularly happy with it. The booms will have to be complete with their tail sections before they can be glued to the wing so I must get on a build another. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted August 2, 2017 Author Share Posted August 2, 2017 Next is the boom 'end' which includes the rather complex transition from the oval of the boom to the swept airfoil section of the fin itself. Like the wings the fin is just two skins with Depron shear webs with no ribs. Although quite a bit of planking is required for the 'transition' section at the base. With the fin glued onto the end of the boom a first dry fit to see how it sits on the wing. As all the loads are carried by the skin the glued joint between the boom and wing has to be an exact fit. After many hours of cutting, shaping and fitting small pieces of planking at last some rel progress. The booms with their fins glued in place. The piece of string is a pull through for the elevator servo wire. Still more fiddly planking to complete the boom under each wing. By comparison the tail plane should be simple as it is a just a constant chord plank. Quote Link to comment Share on other sites More sharing options...
MattyB Posted August 2, 2017 Share Posted August 2, 2017 Some great skills on show here, but it's not difficult to understand why we don't see many Sea Vixens at the average club patch - it's a fiddly beast to build irrelevant of the materials chosen. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted August 3, 2017 Author Share Posted August 3, 2017 The tail plane goes on with its odd fillets. In full size the tail plane was all moving (for trim as it had an elevator as well) and the fillets moved with it! Mine is fixed and the fillets give it some valuable extra rigidity. At 900 mm span it is not that much smaller than the 1000 mm Durafly (HobbyKing) version but it will be a lot lighter. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted August 6, 2017 Author Share Posted August 6, 2017 The aileron and elevator surfaces are top tape hinged. The servo wires are fed to the Lermon 'stab' Rx which is fitted into a compartment on the underside close to the likely CofG. I now need the battery (it is on a slow boat from China!) as its final position will determine how the wiring is run from the ESCs. At the moment it weighs exactly 8 oz (227 g). The battery will weigh about 3 oz (85 g) so even with the remainder of the fuselage structure and some paint it should be close to my all up target of 13 oz (367 g). Edited By Simon Chaddock on 06/08/2017 01:09:43 Quote Link to comment Share on other sites More sharing options...
Dave Hopkin Posted August 6, 2017 Share Posted August 6, 2017 I still think you have a secret supplier of helium filled depron..................... I get more glue on my fingers than your AUW!!!!!!! Quote Link to comment Share on other sites More sharing options...
Mowerman Posted August 6, 2017 Share Posted August 6, 2017 'Helium filled depron' - now there's a thought. Quote Link to comment Share on other sites More sharing options...
Former Member Posted August 6, 2017 Share Posted August 6, 2017 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted August 6, 2017 Author Share Posted August 6, 2017 David M Thanks for the compliment. Almost exclusively UHU POR with a touch of PVA where a poor joint (and there are a few!) heeds to be filled. It is not that you can't fill a gap with POR and the joint is stronger than PVA but the end result is almost impossible to sand smooth. The Depron sands fine but the POR just doesn't so it always remains proud no matter how much you sand off! Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted August 9, 2017 Author Share Posted August 9, 2017 The full size Sea Vixen had a serious sized radome so in my case it has to be built to the same light weight standard as the rest of the airframe. Planked vertically. There will be 18 planks. Once complete the base former is removed. This is best done straight away as the POR is soft but still sticky enough to hold the edges of the planks together. A small Depron flange is added to the fuselage former both to physically locate the nose and to increase the glue area. Lightweight to the extreme? Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted August 9, 2017 Share Posted August 9, 2017 It is definitely looking like another winner, can't see you going wrong with it now! Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted August 9, 2017 Share Posted August 9, 2017 Hi Simon, Since you helped me out with my problems & questions during my Bella Ballerina build, I suspected you were some kind of a magician... ... now I'm convinced you really are a sorcerer... Amazing job, truly. Cheers Chris Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted August 12, 2017 Author Share Posted August 12, 2017 The 'pointy' bits go on. The solid 'green' bits are built up from layers of 5 mm laminate underlay. It is rather soft but only about half the weight of Depron. As I am still waiting for the battery to arrive it will be onto plan B. Complete the fuselage skin and then cut it open again at the correct spot to built in the battery box and use the cut out bit as the hatch. Not an ideal way of doing things but I have done it before quite successfully. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted August 13, 2017 Author Share Posted August 13, 2017 Moving on with plan B, top deck planking. One last plank still to do - always the most difficult to fit - then onto the cockpit and 'coal hole'.. In the interests of saving weight they will be solid, no glass, being planked in 2 mm Depron like the rest of the fuselage. Quote Link to comment Share on other sites More sharing options...
Tom Thomas Posted August 13, 2017 Share Posted August 13, 2017 Magnetic wires? And why did the vixen have a side mounted cockpit do you think? Model and techniques here are very impressive by the way Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted August 13, 2017 Share Posted August 13, 2017 The cockpit was offset to make room for the "coal hole" described by Simon, in which the radar operator/general dogsbody was incarcerated to operate the electronics. Rather him than me. The Sea Vixen had a pretty lousy accident record and I wouldn't have enjoyed being stuck down there with no real view of the outside world. Edited By Colin Leighfield on 13/08/2017 06:28:39 Quote Link to comment Share on other sites More sharing options...
Dave Hopkin Posted August 13, 2017 Share Posted August 13, 2017 Posted by Colin Leighfield on 13/08/2017 06:28:03: The cockpit was offset to make room for the "coal hole" described by Simon, in which the radar operator/general dogsbody was incarcerated to operate the electronics. Rather him than me. The Sea Vixen had a pretty lousy accident record and I wouldn't have enjoyed being stuck down there with no real view of the outside world. Edited By Colin Leighfield on 13/08/2017 06:28:39 The theory was that with early CRT throwing the operator into the coal hole (with no widow) he would be able to see the display better Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted August 13, 2017 Author Share Posted August 13, 2017 The Sea Vixen off set canopy was not quite unique as some marks of the Canberra had the same particularly the B(I)8 and the PR9 but at least on these marks the second man had an ejector seat! "Magnet" wire. Its the name used for lacquer insulated solid copper conductors as used in the winding of an electro magnet. Edited By Simon Chaddock on 13/08/2017 11:27:47 Quote Link to comment Share on other sites More sharing options...
Tom Thomas Posted August 13, 2017 Share Posted August 13, 2017 I never knew it was 2 up, thought it was just the pilot, and thanks for the magnet wire explainations Simon, something new everyday! Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted August 13, 2017 Author Share Posted August 13, 2017 Colin I am not sure the Sea Vixen's 38% accident record was all that bad for carrier operations of the first generation 'heavy' fast jets. Its compatriot the Supermarine Scimitar suffered a 51% accident rate! It does rather show just how risky it was at the time. Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted August 13, 2017 Author Share Posted August 13, 2017 With the rear fuselage skin complete planking the cockpit area begins. A bit of a fiddle to do but it is at least getting near the end! Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted August 14, 2017 Share Posted August 14, 2017 Looking good now you are on the home stretch. Steve Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted August 15, 2017 Author Share Posted August 15, 2017 At long last all the planking is complete! So all ready to cut it open again at the appropriate point when I have the battery! It weighs 9.3 oz (263g) so positioning the 3.7 oz (105 g) battery will be fairly critical. Quote Link to comment Share on other sites More sharing options...
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