Gary Clark 1 Posted January 4, 2023 Author Share Posted January 4, 2023 I made a balsa trim tab so that I could use that as a mould to make some litho ones but they are only 1/8th wide so was really tricky trying to get the litho to the correct shape without damaging the balsa and a limit to my skill/experience with shaping litho. Anything I have done is much bigger so I gave up and designed one to be 3d printed. Not the "purest" modelling technique but makes life so much easier! Here is what I designed I am currently printing a 43" wingspan P-51 from eclipson so that is taking up the printers time just now but these are very impressive. I will paint it too and you have the airframe of a small warbird for approx £15 in materials I'll put a photo up once it is finished but should be fun. Great thing is that if you break it.....print replacement bits for pennies Gary Quote Link to comment Share on other sites More sharing options...
Gary Binnie Posted January 5, 2023 Share Posted January 5, 2023 Happy New Year! I'm not looking forward to that bit! A tip (that I read from a book but I can't remember which one!) is to temporarily fill the gap in the fuselage with a dummy tailplane centre section spot glued in, you can then use a long sanding block or dowel to match the fuselage contour and fair better to the fin. Very damp in my shed and garage at the moment, too expensive to heat and not at all enticing!! 1. Balsacraft Fw 190 with dummy tailplane. The fin sits on the slab sheet tailplane so it's a good way to get it right anyway. 2. Chris Foss Xtra Wot: Like the Fw 190 the fin butts against the tailplane and a dummy fin allows the blocks to be sanded easily. 3. Looks great but sadly the fin was off centre, makes no difference to the flying thankfully. Quote Link to comment Share on other sites More sharing options...
Gary Clark 1 Posted January 5, 2023 Author Share Posted January 5, 2023 Thanks Gary, thats a great technique. I've used it quite a few times on sport models where the tail parts are flat sheet but gets a bit more difficult when there is an aerofoil shape like the scale spit. Also the fairing don't go all the way back, just around half way down the H stab. I have it shaped now but just letting some filler dry at the joint then I'll get a photo on. Needed to trim a small section from the bottom of the H stab right where the elevator control horn swings. This was a bit tricky with the fin post passing right behind it so make sure you give it plenty of room to move to ensure full deflection of the elevators. As soon as the baby goes to sleep I'll be back in the garage...... Quote Link to comment Share on other sites More sharing options...
Gary Clark 1 Posted January 5, 2023 Author Share Posted January 5, 2023 Tail is complete and now the fuse will get fiberglassed. There are a few imperfections on the balsa and joint at the fin but will sort that properly once glassed. Gary Quote Link to comment Share on other sites More sharing options...
Gary Clark 1 Posted January 6, 2023 Author Share Posted January 6, 2023 top and sides are fiberglassed with 24g cloth. I normally use the skinning epoxy from fighter aces and peel ply but I have an unopened pack of Z-Poxy that needs used up and it's too thick for peel ply I feel. It definitely takes longer to get on and will need a flow coat once dry but gets it used up. Also, the complex curves of a spit would be hard to peel ply as such a big area. I'd probably have to so sides separate. I quite enjoy this stage but its on the dining room table because of the temperature outside, the wife is delighted.... I will let it cure overnight and will try and get some primer on the 3d printed P-51 tonight. Looking forward to seeing how that comes out too Gary Quote Link to comment Share on other sites More sharing options...
Gary Clark 1 Posted January 6, 2023 Author Share Posted January 6, 2023 Ok I've made a decision with the finish of the spit. Way back when I first started this, my intention was to convert it to a Seafire Mk 1b which is essentially a Mk V spit with a hook. After shelfing this project then getting it out again, I was just going to complete it as a Mk 1a Spit but now I think I am going to go back to the Seafire option like below keeps it a bit unusual I think Gary 1 Quote Link to comment Share on other sites More sharing options...
Eric Robson Posted January 6, 2023 Share Posted January 6, 2023 Keep the hook light Gary, you will need to save a lot of weight at the back. Quote Link to comment Share on other sites More sharing options...
Gary Clark 1 Posted January 6, 2023 Author Share Posted January 6, 2023 Planning on making a Fiberglass mould of the area and make it like you would gear doors then add scale details with light balsa or chemiwood. The hook on the Seafire is like an airbrake with a hook on the end and attached just behind where the fairings end under the fuse. Shouldn't add too much weight and if I decide to make it function then I can put a small servo forward to control it. Still trying to find some detailed photos of it so that I can replicate so anyone can help me out I'd much appreciate it Gary Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted January 6, 2023 Share Posted January 6, 2023 Maybe the "real" ones were balanced further back than our models as I saw two Spitfire programs on Sky and in straight and level flight the elevator was slightly down then causing it to give lift. Save the small servo by making it spring loaded and pulling it up when using full throttle a fishing line can then retract it. Quote Link to comment Share on other sites More sharing options...
GrumpyGnome Posted January 7, 2023 Share Posted January 7, 2023 A couple of grams for a servo at the front, with a pull line on a spring loaded hook sounds light - it's what's used on DLGs after all. Personally, I'd have it controlled separately, to avoid having it pulled off on every take off and landing, especially on grass 🙂 Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted January 7, 2023 Share Posted January 7, 2023 What's a DLG ?. Quote Link to comment Share on other sites More sharing options...
Ace Posted January 7, 2023 Share Posted January 7, 2023 Discus launch Glider Quote Link to comment Share on other sites More sharing options...
GrumpyGnome Posted January 7, 2023 Share Posted January 7, 2023 (edited) My little DLG has a piece of springy wire between rudder and fin, and tailplane and elevator, which set the control surface to be deflected one way. A single dacron cable per control surface then runs to the servo so it pulls it to the required position, against the springiness. Edited January 7, 2023 by GrumpyGnome Quote Link to comment Share on other sites More sharing options...
Laurent45 Posted January 7, 2023 Share Posted January 7, 2023 On 30/12/2022 at 17:39, Gary Clark 1 said: Hi Everyone and welcome to Laurent! I am planning on 3D printing my wheel hubs as I have some scale ones designed and ready to go. I could easily print you a set and post them to you if you need them as it is pretty hard to find scale details like this nowadays I've not had time over the festive period to get out so no progress on mine but hopefully back to it in the next few days Gary Hi Gary , it could be great for the hubs With big pleasure if you can print me a set !! laurent Quote Link to comment Share on other sites More sharing options...
Gary Clark 1 Posted January 7, 2023 Author Share Posted January 7, 2023 Hi Laurent, No problem, I just need the exact diameter you would like and I will print. Let me know when you require them and PM me your adress. I will be using the 5 spoke but the options below Things like this make 3d printing excellent and much cheaper than getting custom hubs made as this way only used a few pence of filament Gary 2 Quote Link to comment Share on other sites More sharing options...
Laurent45 Posted January 13, 2023 Share Posted January 13, 2023 On 07/01/2023 at 23:14, Gary Clark 1 said: Hi Laurent, No problem, I just need the exact diameter you would like and I will print. Let me know when you require them and PM me your adress. I will be using the 5 spoke but the options below Things like this make 3d printing excellent and much cheaper than getting custom hubs made as this way only used a few pence of filament Gary Great design . I m not yet a this point of construction . I d like to see the result on the wheels Quote Link to comment Share on other sites More sharing options...
Gary Clark 1 Posted June 12, 2023 Author Share Posted June 12, 2023 Hi All, Well after being away with work alot, a big chunk of life and every other excuse, I've finally got the Spit back on the build board. The temp is better to get on with priming so the first coat has been on and sanded with the first bits of filler added. Not much to show with photos but next job is more sanding and priming then panel lines before the final primer coat. As soon as that's done, it's on to the wing which I'm a little worried about as I truly hate fitting retracts 🤣 any help is welcome as I always find this hard no matter how often I do it! Gary Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted June 13, 2023 Share Posted June 13, 2023 Retracts can be a headache, my new PC-9 mechanical ones are modified my seagull, so far it's cost me a retract servo 😈so mains are now electric, but my Marutaka Spitfire is still good with it's Hanno Pretner mechanicals and Futabe retract servo after 25 years of flying.😃 Quote Link to comment Share on other sites More sharing options...
dave parnham Posted June 13, 2023 Share Posted June 13, 2023 just started reading this from page one Gary.....i have a shelved BT109 in a box which i broke its back while trying the boat method type planking on the back half, now looking at restarting this. Quote Link to comment Share on other sites More sharing options...
Gary Clark 1 Posted June 20, 2023 Author Share Posted June 20, 2023 I committed a d bought the Electron ones as I've just got fed up of the cheap ones breaking after a few uses. I need to get started on the wing soon to just get on with it and stop thinking about it. Looking forward to having it done. Hi Dave. It's very satisfying repairing/correcting a build I think. It means it isn't in the loft mocking you anymore 🙂 Off to the garage so hopefully get the sanding complete tonight and ready to spray soon. Might put panel tape on first then spray to save a coat of primer, it all adds up. Once thats done, its onto the wing Gary Quote Link to comment Share on other sites More sharing options...
Gary Clark 1 Posted June 20, 2023 Author Share Posted June 20, 2023 So I managed to get out and do some sanding but the light started to fade outside so I called it quits for the night as I wanted to sand outside to reduce dust in the garage. I decided to start putting the parts together dry for the starboard wing to see what I need to sort before I start gluing and I have a few changes to make from the plan. Below is the join at the centre section and I've decided to extend the 1/4" spar (that sits just in front of the main spar shown with the red arrow) by 1 rib and I'll also extend the ply dihedral brace to here also as this model has suffered wing folds on other builders As a not for people who are new to scale builds (or many other sport builds too) a thing that can be confusing is the little notches cut into the mainspar to fit the narrower ribs rather than thinning the spar along its length. Just thought I'd point it out I still have some ply doublers to cut and the ribs are about 1/8" short at the trailing edge so have to extend them or add a thicker trailing edge but worried about any extra weight behind the CG. Feels nice to be building again Gary Quote Link to comment Share on other sites More sharing options...
Paul De Tourtoulon Posted June 21, 2023 Share Posted June 21, 2023 Sorry Gary, but I have at least 4 planes with these, and they are really good, a couple modified to twist and turn, all on petrol planes. Quote Link to comment Share on other sites More sharing options...
Jon H Posted June 21, 2023 Share Posted June 21, 2023 On 06/01/2023 at 19:25, Gary Clark 1 said: Ok I've made a decision with the finish of the spit. Way back when I first started this, my intention was to convert it to a Seafire Mk 1b which is essentially a Mk V spit with a hook. After shelfing this project then getting it out again, I was just going to complete it as a Mk 1a Spit but now I think I am going to go back to the Seafire option like below keeps it a bit unusual I think Gary Been out of the loop on this thread for a while and stopped back for a catch up. I am considering this same paint job for my modified TF Spit and might have to find something else now! 🤣 13 hours ago, Gary Clark 1 said: bought the Electron ones These are very good and on my radar for future projects. Did you get the 95 degree? Quote Link to comment Share on other sites More sharing options...
GrumpyGnome Posted June 21, 2023 Share Posted June 21, 2023 Won't cutting notches in the mainspar reduce its strength more than gradually reducing it's size? Quote Link to comment Share on other sites More sharing options...
Gary Clark 1 Posted June 21, 2023 Author Share Posted June 21, 2023 Ah nice Paul, you've done way better than I have then. I'll have a look at those for some of my other models then, thanks. Well if you do it first Jon I can decide if I like it or not 🤣 still have to decide what kind of paint to use also. Hi Grumpy. The notch then gets filled with the rib and glued so you end up with a thinner wing section with more balsa in both the spar and rib. The notch means there is more contact between the rib and spar too Gary Quote Link to comment Share on other sites More sharing options...
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