David Davis Posted February 2, 2020 Author Share Posted February 2, 2020 I have started the construction of the Big Guff's wing. As I may have stated before I am following the original "egg box" method of construction using the materials supplied in the kit. The plan shows that the first three ribs, from the centre rib outwards, are spaced at 3", 2.5" and 2" from the centre rib ( about 7.6 cms, 6.5 cms and 5 cms respectively.) Then there are eleven ribs spaced at 3" centres. I carefully marked the spars and cut slots in the relevant positions to take the ribs. Whilst the first few ribs line up fairly accurately, the further out towards the tip you go, the marked postions on the plan become less and less accurate. I have consequently ignored the plan and worked to my own markings. I suppose that the plan has stretched or become distorted with repeated photocopying. Each rib is marked at the position of the spar and you have to cut out a slot in each rib half the height of the rib at the spar position. In a couple of cases I made the spar slot too tight and broke the rib when fitting it. Lesson learned for the port wing. I note that the trailing edge is simply a piece of 1/4" x 1" strip not TE as I expected but this is not a problem. The spars are resting on 1/8" (3mm) scrap because of the undercambered wing section. Quote Link to comment Share on other sites More sharing options...
David Davis Posted February 27, 2020 Author Share Posted February 27, 2020 Construction of the Big Guff continues. I have built the starboard wing but I am waiting for one of my trainee pilots, a qualified engineer, to make up the four little metal brackets which connect the two wing halves together before sheeting the leading edge, centre section and wing tips. I found the wing tips particularly problematic and a considerable amount of cutting, shaping, filing and general fettling was required to get the wing into its current state. Further planing and sanding is required. The plan was not much help because it had become distorted with repeated photocopying. We are holding a static display of models in a local community centre over the weekend of 6th-7th March. I plan to display the Big Guff in its half-built state. Quote Link to comment Share on other sites More sharing options...
David Davis Posted March 19, 2020 Author Share Posted March 19, 2020 Still a long way to go but we all do this don't we? Metre rule in the first picture gives you an idea of the size of the model. Quote Link to comment Share on other sites More sharing options...
David Davis Posted April 2, 2020 Author Share Posted April 2, 2020 It's been exactly a year since I started this build. This is as far as I've got... ...and I've found out that you can fold the wings which will make storing and transporting a model of this size easier. I am awaiting the delivery of some nuts and bolts before I start sheeting the wings. Quote Link to comment Share on other sites More sharing options...
David Davis Posted April 3, 2020 Author Share Posted April 3, 2020 Well I found enough little nuts and bolts for one wing and managed to get the top wing sheeting onto the starboard wing yesterday. It's amazing how even 1/32" balsa sheet makes the wing so much more rigid. There's identical sheeting to go onto the underside of the wing too. Do you think I've used enough pins? Quote Link to comment Share on other sites More sharing options...
David Davis Posted April 12, 2020 Author Share Posted April 12, 2020 Once I have finished fitting the 1/32" sheet to the port wing, it will be time to think about covering the underside of the wings. The Big Guff has an undercambered wing section and I haven't covered an undercambered wing since I built my Junior 60 in 1988! However, thinking about it, I must have covered a Junior 60 wing at least three times because originally it was covered in Neutral Solartex, a sort of translucent white and now it's orange. I built another one for electric power. It's the red and yellow pictured below alongside my first one in its orange scheme. I regret that I do not have a picture of the Junior 60 in its original olive drab and Neutral colour scheme. Probably just as well! I cannot recall having a problem getting the Solartex to stick to the undercamber of a Junior 60 but others have suggested coating the ribs and spars in Covergrip or thinned PVA white glue first. Another suggestion has involved using cyano to glue the Solartex in place when the underside has been covered. What do you think? The views of the cognoscenti are, as always, keenly sought. Quote Link to comment Share on other sites More sharing options...
Outrunner Posted April 12, 2020 Share Posted April 12, 2020 David. I recently recovered my Junior 60 using tissue over doculam. I used balsalock around the edge of the ribs and spars, it stuck as good as the original Solartex but much lighter. We went into lockdown before I managed a test flight. Enjoying your Big Guff build, should be ready for when we can fly again. Stay safe. Phil. Quote Link to comment Share on other sites More sharing options...
David Davis Posted April 13, 2020 Author Share Posted April 13, 2020 Hi Phil I'm out of Balsalock and Solarfilm Sales are not trading until the Covid 19 restrictions are lifted. I'll send off for some Covergrip. It won't do any harm. Stay Safe. David Quote Link to comment Share on other sites More sharing options...
David Davis Posted April 14, 2020 Author Share Posted April 14, 2020 Gentlemen, The Big Guff Build. After 54 weeks since I started to build it, the last piece of wood has been glued into place! Time for a celebration! Stay safe Quote Link to comment Share on other sites More sharing options...
David Davis Posted May 3, 2020 Author Share Posted May 3, 2020 I've been a bit distracted by other projects so work on the Big Guff had stopped until the day before yesterday when I began to glue the elevator hinges into place. That's when I noticed that one end of the elevator was at least 3mm (1/8" higher than the other and nothing I could do with heat would make it flat. In the end, heating the covering caused the leading edge of the elevator to deform. There was nothing for it but to remove the covering, cut away the leading edge of the elevator and replace it with one made from slightly thicker and harder balsa. Once the glue had dried I removed it from the building board. It was still not flat! I hit upon the idea of adding 3mm square diagonal braces between each of the ribs. I have a SLEC balsa stripper but didn't bother to get it out for this little job, just cutting 3mm strips from scrap balsa supplied with the kit using the TLAR principle. Having cyanoed them into place I found that I had fitted them incorrectly. The diagonals on the outer bays for example were sloping in the same direction not in opposing directions! Oh how I laughed! A major Homer Simpson moment! I removed the offending article from the building board and it still reminded me of a Texas Longhorn but all was not lost. I pinned the offending article to the board using lots of my new plastic headed pins and added cross bracing to those braces which were already installed. It's flat now. I've just been into town to the bakers. There is a big notice up in the barber's shop saying that they will open on 11th May accept appointments from 4th May. Maybe we'll be allowed to go flying soon. Edited By David Davis on 03/05/2020 11:08:37 Quote Link to comment Share on other sites More sharing options...
David Davis Posted May 6, 2020 Author Share Posted May 6, 2020 I have experienced three steps forward two steps back in the Big Guff build. I initially installed a switch with a remote push off-pull on button on the end of a rod through the fuselage but then thought better of it. It was only a cheap switch with three sets of cables coming out of it, one for the rx battery, one for the receiver itself and the third as a charging lead. You know the type. I was concerned about what might happen if the switch were to fail. I had several new switches of of a superior quality so I removed the cheap one and fitted a better one. However, the switch wouldn't fit where the old one was installed so I fitted it inside the fuselage on one of the rails which used to support the Good brothers' receiver. However, to switch on the receiver I now have to open the door! I was not happy with the existing door so I built a new one, reinforcing the joints with carbon fibre rod. The new door is a much better fit though it's still not perfect, woodwork never having been my strong suit. That said every model I've ever built has flown, some better than others I'll admit. The door still needs sanding, doping, painting and glazing. I have connected up the rudder and elevator servos to their closed loop cables and pushrod respectively and I've fitted one of those new Spektrum AR410 receivers, the type with the internal antenna. Everything works. I now just have to finish preparing the wings for covering and wait for the restrictions to be lifted so that my friend can come round with his welder to make up the undercarriage. Quote Link to comment Share on other sites More sharing options...
paul d Posted May 6, 2020 Share Posted May 6, 2020 looking fantastic David! I like the idea of the door. Those AR410 rx's are marvellous, got one in my Gamine and intend to fit another in my latest project ( keil Kraft Bantam). Quote Link to comment Share on other sites More sharing options...
David Davis Posted May 6, 2020 Author Share Posted May 6, 2020 Thank you for your kind remarks Paul. The door was essential in 1938 because the receiver had to be tuned to the transmitter before every flight. I was going to omit it but in the end went with the original construction. Do you know what Gamine means in French? Edited By David Davis on 06/05/2020 10:57:02 Quote Link to comment Share on other sites More sharing options...
Ace Posted May 6, 2020 Share Posted May 6, 2020 Do you know what Gamine means in French? Edited By David Davis on 06/05/2020 10:57:02 Interesting Quote Link to comment Share on other sites More sharing options...
paul d Posted May 6, 2020 Share Posted May 6, 2020 Does it Ace? interesting, my Gamine is the last model designed by Vic Smeed, flys a treat on rudder only. Quote Link to comment Share on other sites More sharing options...
Ace Posted May 6, 2020 Share Posted May 6, 2020 Nice model Paul Lockdown, few beers and with a squint - must get out more. Quote Link to comment Share on other sites More sharing options...
David Davis Posted May 6, 2020 Author Share Posted May 6, 2020 No Ace, Gamine doesn't mean "interesting" in French, that's intéresant! Gamine means a Lass in French. The male equivalent would be Gamin. Quote Link to comment Share on other sites More sharing options...
Ace Posted May 6, 2020 Share Posted May 6, 2020 David, "Interesting" - in what I understand Gamine's meaning was in French. "A slim elegant woman who is, or perceived to be mischievous, teasing or sexually appealing". Wonder if Vic knew? Quote Link to comment Share on other sites More sharing options...
David Davis Posted May 9, 2020 Author Share Posted May 9, 2020 Posted by Ace on 06/05/2020 22:40:16: David, "Interesting" - in what I understand Gamine's meaning was in French. "A slim elegant woman who is, or perceived to be mischievous, teasing or sexually appealing". Wonder if Vic knew? Actually "gamine," also means a young woman with short hair, Perhaps a French "Tomboy!" To return to the Big Guff, I just need to get my tame welder to make up an undercarriage and we're good to go! One metre long ruler lends scale to the model. It's not too bad if you don't look too closely! God knows how that line got in there. Edited By David Davis on 09/05/2020 15:14:12 Quote Link to comment Share on other sites More sharing options...
paul d Posted May 10, 2020 Share Posted May 10, 2020 looks wonderfull David! maybe a little decoration on the wing needed? Quote Link to comment Share on other sites More sharing options...
David Davis Posted May 10, 2020 Author Share Posted May 10, 2020 Thanks for the kind remarks Paul! I was thinking of putting some vinyl lettering on the fin. I'm no good with painted decoration. I haven't made up my mind about fuel-proofing the Solartex yet. I know it's fuel proof but it soon starts to look grubby. Edited By David Davis on 10/05/2020 10:16:20 Quote Link to comment Share on other sites More sharing options...
paul d Posted May 10, 2020 Share Posted May 10, 2020 To my mind vintage types look better once they have a bit of fuel/exhaust staining. It really needs it's name,designer and year on the wing, always a good conversation starter at the field. Quote Link to comment Share on other sites More sharing options...
David Davis Posted May 10, 2020 Author Share Posted May 10, 2020 On one side of the fin I am going to have: "Dr Walt Good's Big Guff National Radio Control Championship Winner 1938-1947" On the other, the same thing in French! Plus two little American flags. Quote Link to comment Share on other sites More sharing options...
paul d Posted May 10, 2020 Share Posted May 10, 2020 Superb! can't wait to see it fly.. Quote Link to comment Share on other sites More sharing options...
David Davis Posted June 2, 2020 Author Share Posted June 2, 2020 Quick update on the Big Guff's progress. The undercarriage was welded up, painted and the wheels attached but when I pushed the model across the workshop floor the wire broke. Obviously the heat of the welding process was too much for the wire and had weakened it considerably. A blessing in disguise really because the first undercarriage was too tall. I had used Walt Good's original measurements and that was for the raked-forward undercarriage. I obviously had to shorten the undercarriage to get rid of the broken section so now it looks much more like the post-war version. Andy is coming round later and we plan to silver solder it. I rigged the Big Guff last night in the workshop with the wheels just pushed on to the axles and I checked it for centre of gravity, not an easy task in a confined space! The model is too tall off the ground to enable the use of my centre of gravity rig so I used the fingers under the wing method and if anything the model is slightly nose heavy. Once the soldering has been done then it's only a question of painting and fuel proofing the undercarriage, running up the engine and waiting for a calm day before that maiden flight. There's not much chance of that happening here for several days because we are in for a few thunderstorms. The vinyl lettering referred to in my previous post has been ordered and I plan to collect it on Friday. Edited By David Davis on 02/06/2020 06:45:27 Quote Link to comment Share on other sites More sharing options...
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