David Davis Posted February 21, 2021 Share Posted February 21, 2021 Regular contributors to this forum will know that over fourteen months I built a Big Guff and flew it for the first time last (northern hemisphere) summer but for the benefit of newcomers here is the buld blog over on RC Groups: https://www.rcgroups.com/forums/show...f-This-is-mine. The Big Guff, designed by Dr Walt Good, was one of the first models specifically designed for radio control and it first flew in the late 1930s. It was a model which I had admired from the since at least 1988 when I first took up radio controlled flying. Sherwood Heggen also built one. His build blog is here: https://www.rcgroups.com/forums/show...Good-Big-G-uff Mine went up in smoke last Sunday when an unsupervised LiPo which was on charge burst into flames and set fire to it. Details here: https://www.rcgroups.com/forums/show...ff-Met-Its-End Fortunately the wings were stored elsewhere. I wasn't going to make its rebuild a priority but all and sundry have urged me to rebuild it and a club member, Guy Auvieux, volunteered to rebuild the fuselage. I thought that if someone else built the fuselage, that the model somehow would not have been mine. I've compromised by letting him build the tail surfaces so yesterday morning found me with a blue biro in my hand changing all of the Imperial measurements to metric and outlining the modifications I had made to the structure. I had enlarged the size of the elevator for example by moving the pivot point forward and had bolted the tail to the fuselage rather than relying on elastic bands. There was an informal gathering yesterday afternoon at the club hut, it was too windy to fly. Guy was present so I gave him plans and some wood. I've been warned that Guy builds very quickly so I'd better be on my metal. I will be contacting SLEC tomorrow to order some 1/32" sheet and four foot lengths of 1/4" sq. I will be building a door into it and will stick a big No 2 on the nose! A few pictures below to remind you of my Big Guff. Incidentally when the Big Guff caught fire it also set fire to the WOT 4XL alongside. Quote Link to comment Share on other sites More sharing options...
Graham Davies 3 Posted February 21, 2021 Share Posted February 21, 2021 Great to hear this David. It was a very sad loss that fortunately didn't result in more damage or injury. Good luck with the rebuild. Graham 1 Quote Link to comment Share on other sites More sharing options...
David Davis Posted February 21, 2021 Author Share Posted February 21, 2021 Thank you Graham. I'm going to build the door into it too. Quote Link to comment Share on other sites More sharing options...
EarlyBird Posted February 21, 2021 Share Posted February 21, 2021 David, I have been following along out of interest, I was looking at the photo of the two fuselages at first I could not work it out but then realised that they are hanging on the wall, then it made sense. Is that the PSU under the Big Guff tail and the charger just on the edge of the photo? I was just wondering what happened to them? Just curious... Quote Link to comment Share on other sites More sharing options...
David Davis Posted February 21, 2021 Author Share Posted February 21, 2021 That's right Steve. The fire was limited to where the two models were hanging on the wall. A 10 litre plastic paint pot which I was using as a waste bin was damaged and there is some smoke damagejust about everywhere. The PSU and charger were unaffected other than being covered in soot. i have an appointment with the insurers on Tuesday. Quote Link to comment Share on other sites More sharing options...
EarlyBird Posted February 21, 2021 Share Posted February 21, 2021 I was wondering if the PSU, being so close to the tail, had caused the fire but obviously not if it still works. The battery is no where near the fuselages but again the photo was taken at a different time. I think too much which can make me a pain, so I have been told. Quote Link to comment Share on other sites More sharing options...
David Davis Posted February 22, 2021 Author Share Posted February 22, 2021 I've a few matters to consider right off the bat. I had a look at my balsa stocks and found that while I'd only got four strips of 1/4" square, I have nineteen in a size is very slightly larger. Using my much abused RCM&E guage I each able to confirm that the larger section wood was too big to fit into the 1/4" slot and too small for the 3/8" one. My cheap and cheerful Draper guage measured the larger wood at 7.5mm or about 0.29". Pictures below may clarify or confuse! Where I'd bought this wood from I cannot recall but it is certainly neither 1/4" square nor 3/8" square. I see that SLEC advertise their 1/4" square as 6.5 mm square and I'm informed that they have been machining balsa to metric dimensions for some time. French suppliers specify 6mm x 6mm. I retired to central France in 2015 incidentally. I am left in a bit of a quandry. Should I use the thicker wood for the Big Guff's basic fuselage construction or should I order some 6mm square from a French supplier? The larger section balsa seems to be of a lighter weight than that which I would normally use for fuselage longerons but the fuselage will be completely clad in 1/32" balsa anyway. If I order some 6mm square what am I going to use the 7.5 mm stuff for? 1 Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted February 22, 2021 Share Posted February 22, 2021 glad to hear/read that your building a replacement David.. ken anderson...ne..1..Guff dept. Quote Link to comment Share on other sites More sharing options...
David Davis Posted February 22, 2021 Author Share Posted February 22, 2021 23 hours ago, EarlyBird said: I was wondering if the PSU, being so close to the tail, had caused the fire but obviously not if it still works. The battery is no where near the fuselages but again the photo was taken at a different time. I think too much which can make me a pain, so I have been told. ...and nobody knows the size of the explosion when the LiPo went up either. What is obvious is that the Big Guff caught fire first and set fire to the WOT4 XL. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted February 22, 2021 Share Posted February 22, 2021 @David Davisthe BG’s fuse is just crying out to be open framework construction covered with Solartex or lam film rather that 1/32nd balsa! Quote Link to comment Share on other sites More sharing options...
David Davis Posted February 22, 2021 Author Share Posted February 22, 2021 11 minutes ago, Ron Gray said: @David Davisthe BG’s fuse is just crying out to be open framework construction covered with Solartex or lam film rather that 1/32nd balsa! But the original was covered in 1/32" balsa. Quote Link to comment Share on other sites More sharing options...
kc Posted February 22, 2021 Share Posted February 22, 2021 (edited) Good to hear you are starting the rebuild . The balsa you have may be 5/16 sq /8mm sq which is available from SLEC if you need more. I suggest you make sure you have the latest replacement cost worked out when your insurer comes - balsa has become more expensive , covering is more expensive as Solartex is near unobtainable and radio gear , engines/motors more expensive in the last year. I would also suggest you inform them of your idea to stop this happening again - i.e. ammo box or other metal container and better quality charger plus smoke alarm in case they say it wont be insured in future...... Edited February 22, 2021 by kc amended Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted February 22, 2021 Share Posted February 22, 2021 4 hours ago, David Davis said: But the original was covered in 1/32" balsa. Does that really matter, given the shortage of balsa? Quote Link to comment Share on other sites More sharing options...
David Davis Posted February 22, 2021 Author Share Posted February 22, 2021 30 minutes ago, Ron Gray said: Does that really matter, given the shortage of balsa? I want to make the model as authentic as possible. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted February 22, 2021 Share Posted February 22, 2021 Fair enough DD Quote Link to comment Share on other sites More sharing options...
David Davis Posted February 23, 2021 Author Share Posted February 23, 2021 I decided to buy some 6mm square this morning from a French supplier, as well as some 1mm sheet. Then at about 10.00 I received a couple of replies to a thread I had started over on RC Groups stating that using the 7.5mm balsa would be alright especially as the balsa was lighter than I normally use for longerons. As one of these respondents was the former British and Irish glider champion, I thought, "That's good enough for me!" I will use the 6mm square for another vintage project, the Guidato which is a model which I've admired for some time. https://outerzone.co.uk/plan_details.asp?ID=7378 I'm even toying with the idea of finishing the fuselage and fin in a different colour. Quote Link to comment Share on other sites More sharing options...
David Davis Posted February 28, 2021 Author Share Posted February 28, 2021 I have started the rebuild using the thicker section balsa. Let's see how long it takes me to finish it. Metre rule in the second picture lends scale to the project. It is being built with the door! 3 Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted February 28, 2021 Share Posted February 28, 2021 Good to see the rebuild has started. ? Quote Link to comment Share on other sites More sharing options...
Chris Walby Posted March 1, 2021 Share Posted March 1, 2021 Following with interest and good to see a suitably up scaled version ? Quote Link to comment Share on other sites More sharing options...
David Davis Posted March 1, 2021 Author Share Posted March 1, 2021 43 minutes ago, Chris Walby said: Following with interest and good to see a suitably up scaled version ? It's not scaled up Chris, the model is enormous! I'm simply using slightly bigger balsa than the 1/4" (6mm) sq which I used on my first Big Guff. The wood measures about 7.5mm or 0.29". I am using it because I have plenty in stock and cannot think of another use for it. I was concerned about this wood adding too much weight to the rear but I'm assured that it won't be a problem. My usual English supplier of balsa wood is currently having problems shipping balsa to the EU post Brexit so I've been forced to order 1mm balsa from a French supplier to clad the fuselage rather than 1/32" which is 0.8mm. I'll have to do some vigourous sanding! I plan to start the second side either this evening or tomorrow. Once the glue has dried thoroughly on both sides I face another minor problem. Because the "plan view" of the fuselage was so distorted I cut it away from the rest of the plan and used it to light the wood burner! Now I have no indication of how wide the fuselage should be! Fortunately I still have Peter Russell's book "Vintage Model Aeroplanes" where the plan is reproduced in miniature. However, I've loaned it to one of my trainee pilots, a Belgian chap called Frans. He was so impressed by the flying characteristics of my Double Sized Tomboy that he wants to build a vintage model. The first choice was the Ben Buckle Radio Queen but as Colin Buckle is currently recuperating after an operation, we've opted for an Electric Junior 60, that being the one of the kits which Colin has in stock at the moment. Frans has never built a model before so I'll have to show him the ropes. I'll see what the all up weight is of the bare Big Guff fuselage. I may opt for tissue and dope on the fuselage, rudder and fin rather than the Solartex of No 1, a method of covering which I haven't used for nearly sixty years!. Quote Link to comment Share on other sites More sharing options...
Ron Gray Posted March 1, 2021 Share Posted March 1, 2021 @David Davis For the width of the fuse can't you look at the underside fo the wing to see if there are any marks where it fitted? Quote Link to comment Share on other sites More sharing options...
David Davis Posted March 1, 2021 Author Share Posted March 1, 2021 (edited) 29 minutes ago, Ron Gray said: @David Davis For the width of the fuse can't you look at the underside fo the wing to see if there are any marks where it fitted? Good point Ron, but I've just remembered that Peter Russell himself wrote to me in 1992 and I've kept his letter ever since. Proves how much I've always admired the Big Guff! With the letter he sent me photocopies of the plan as published in his book so I now have the dimensions. At the LE of the wing the fuselage should be 6 1/16" wide (six and one sixteen inches or 15.4 cms) and at the TE just six inches. In between it's supposed to be six and three sixteenths wide! I'm undecided about making up formers at the wing LE and TE position. The original didn't have them. Edited March 1, 2021 by David Davis Spelling. Former grammar school boy! 1 Quote Link to comment Share on other sites More sharing options...
David Davis Posted March 2, 2021 Author Share Posted March 2, 2021 Guy Auvieux, referred to in the first post has got this far with the tailplane. I will have to get my skates on! The width of the fuselage at the extreme end is very indistinct in the photocopy which Peter Russell sent me. I fired off an email to Sherwood Heggen who is also referred to in my first post and he came back with the dimensions. The reconstruction is turning out to be an international effort! 1 Quote Link to comment Share on other sites More sharing options...
David Davis Posted March 3, 2021 Author Share Posted March 3, 2021 I've just finished the second side of the Big Guff's fuselage. It's amazing how much wood is involved in the construction. I started out with 19 lengths of four-foot strip and have finished with only 4 and a bit. 1 Quote Link to comment Share on other sites More sharing options...
David Davis Posted March 8, 2021 Author Share Posted March 8, 2021 I've got this far with the Big Guff's fuselage. Because the gluing surface is 16% larger with this wood than with the normal 1/4" sq (6mm square) I've decided not to fit my usual 1/64" (0.4mm) ply gussets to the joints between the longerons, uprights and spacers. The whole lot's going to be covered in balsa wood sheet anyway. Note the smoke blackened walls in the background. 4 Quote Link to comment Share on other sites More sharing options...
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