Julian Murch Posted January 24, 2019 Share Posted January 24, 2019 Now in my retirement I have returned to model making after a break of many years. I am completing a Keil Kraft Chief started about 35 years ago !! I had completed the frame but not covered it. I have now covered the wings and am about to start the fuselage. I did pin the wings down during doping to prevent twisting and am wondering if I should do the same with the body. Any thoughts would be appreciated. Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted January 24, 2019 Share Posted January 24, 2019 Hi Julian and welcome to the forum. I'm looking forward to seeing people's opinion on this question. I think you'd be fine without jigging the fus. I think I'd be trying to cover the same section either side, each session, if you see what I mean?. This should balance out any twisting. Quote Link to comment Share on other sites More sharing options...
Former Member Posted January 24, 2019 Share Posted January 24, 2019 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted January 24, 2019 Share Posted January 24, 2019 I never jigged fuselages when doping. Just made sure that the doping was even and all done at once. Being square or variations on circular does not normaly cause uneven tensions during tightening. Thinking back to my earlier days, and my Mercury Mentor,KK Competitor and later KK Gypsy never had a fuselage twisted. . Quote Link to comment Share on other sites More sharing options...
Nigel R Posted January 24, 2019 Share Posted January 24, 2019 Most fuselages don't have structures that will warp very much when complete. Usually there is enough triangulation to prevent it. A wing on the other hand, particularly old style open construction (or any open flat framework), will warp like a pringle given half the chance - hence pinning them down. Quote Link to comment Share on other sites More sharing options...
Former Member Posted January 24, 2019 Share Posted January 24, 2019 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted January 24, 2019 Share Posted January 24, 2019 Julian, no doubt you are aware of all the different covering films, which can be used as an alternative to tissue and dope. Sadly Solarfilm has ceased production but they are still trading on-line and selling off their remaining stock. If you fancy some lite-span for a future lightweight model build you better stock up now, as when it is gone it is gone, as they say! You will also need Balsalock too, to apply to the balsa frame to get it to stick, also available from Solarfilm. Perhaps someone knows of a similar lightweight product to Litespan that is available? Perhaps you are a traditionalist Julian and just like the smell of the dope . Welcome to the forum, by the way. Quote Link to comment Share on other sites More sharing options...
Julian Murch Posted January 24, 2019 Author Share Posted January 24, 2019 Wow I am very impressed with the number of replies so soon. Are we all retired? Thanks for the info and advice I will continue and do all sides at once. I did think that the 3 main formers at the cabin would probably hold it in place. There was one issue with the wings. When I packed them up on the board to dry with small pieces of balsa, they all of course stuck fast and had to be cut down. Version 2 used some old Meccano strips screwed to plywood as supports thus reducing the surface area in contact. As I said originally I started this kit 35 years ago and it is a miracle it survived in the roof space all those years. Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted January 24, 2019 Share Posted January 24, 2019 welcome back from me also Julian, perfect timing, Ripmax are re-introducing some of the old Keil Kraft designs...enjoy retirement.... .... ken anderson....Keil Kraft dept., Quote Link to comment Share on other sites More sharing options...
Julian Murch Posted January 25, 2019 Author Share Posted January 25, 2019 Yes I saw the article in RCM&E about the Gipsy and the thought of fitting radio control. I did toy with the idea of that with the Chief but that is probably beyond my capabilities at present. I will learn to walk first but in the future who knows? Again I am grateful for all the feedback here. Quote Link to comment Share on other sites More sharing options...
PatMc Posted January 25, 2019 Share Posted January 25, 2019 Hi Julian, welcome to the forum, good luck completing & flying the Chief. If you intend flying it free flight don't forget to fit a dt & use it every flight. I built a KK Chief from a kit in the early '70's. Covered with Monokote (The first of the covering films available) it originaly flew on single channel. Launch from the flat was either by hand tow or a bungee. The bungee was made up from 1/4" flat rubber & fishing line, IIRC it was about 50 or 60 yards total length. I also flew it quite a lot S/C as a slope soarer. It was converted to rudder/elevator when I got my first multi gear. The extra weight of 2 full size Futaba servos, Rx & 500 nicads ruled out flat field flying so it was then flown exclusively as a sloper. After much service & many repairs it was retired, the fuselage & tail were scrapped but the wings, undamaged & still in good nick, were stored in the loft. Sometime in the '90's I built a new fuselage & tail (actualy the third of each) cleaned up the wings (originals), then installed lightweight servos, rx & smaller battery. I never did like the plastic covering film on this model so this time it was covered with with tissue over mylar. Weight was now less than with the SC gear. The rebuild near completion... ... ready to fly for re-maiden. The Chief has been stored away for a few years now. The tissue has a few tears & patches but the woodwork is good. I'll be re-covering it again, hopefully in the near future, this time using tissue over laminating film. Hope the tale of my Chief's history hasn't proved too boring. Quote Link to comment Share on other sites More sharing options...
robert chamberlain Posted January 26, 2019 Share Posted January 26, 2019 I have built fuselages with and with out a home made jig. OK results either way if careful. What I have found useful is to buy a meter of aluminum "L" shaped stock and cut it up into 1 1/2" pieces. Then drill very small holes into one leg for "Map Pins" to secure them to the board. Nice 90 degree upright! Cheap and cheerful.---Bob in Kansas Quote Link to comment Share on other sites More sharing options...
Julian Murch Posted February 8, 2019 Author Share Posted February 8, 2019 I have not touched the model for a few days but I am very concerned to see that the tissue has split in several locations to the wings, mostly where it is over the ribs. When I laid the tissue I think I did not use too much pressure to stretch it but I did straighten out the ripples. I have given the wings 2 full coats of dope undiluted. I can of course repair the splits with new pieces of tissue but what if this is going to be a continuing problem. Am I best advised to stop and try a new project? It is after all over 35 years old !! Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted February 8, 2019 Share Posted February 8, 2019 If all else fails you could strip off the tissue on the wings and try some lifespan instead, which I feel you will find much more satisfactory. You have to apply some Balsalock first to the ribs, let it dry before ironing on the litespan. I wouldn't give up on the project yet Julian. Edited By Piers Bowlan on 08/02/2019 14:49:03 Quote Link to comment Share on other sites More sharing options...
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