Martin McIntosh Posted January 15, 2014 Share Posted January 15, 2014 That is looking fantastic Martyn. Surprised that you found the servo wiring on the large side for high density D con. Did you twist the wire ends together first? Probably not an easy job unless you do it for a living as I do. I do hope that you have supported the joints as I suggested. When you say a 1mm gap, is that between the wing surface and the wheel? That would be OK but I expect that you know that there must be a clearance of at least 6mm fore and aft. Span wise it does not matter. I use Depron discs to keep the lining circular-ish whilst fitting the balsa. A slightly oval shape sometimes helps. Too late now eh. I find this to be a rather difficult job on a built up wing. Foam is a doddle. Martin Mc. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 15, 2014 Author Share Posted January 15, 2014 Hi Martin. Thanks The wheel recesses into the wing very nicely, so well in fact that I was considering fitting undercarriage doors as well. The gap I was referring to is between the wheel (tyre) and the wall, it is a VERY snug fit. If you think it should be bigger then I am happy to redo them. I am not especially happy with the construction and to give a 6mm gap all round will be a give me a 2nd attempt at getting it right. This time, I will build the wall around a suitable former and then glue it in place in one go (providing that is do manage to cut a circular hole this time... Martyn Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 15, 2014 Author Share Posted January 15, 2014 Sorry - forgot to mention. Soldering and electronics - I used to do that sort of stuff for a living as well - when I was a proper engineer. The wires were well twisted, but just a few strands too big. I have reinforced the joints with heat shrink and there are no dry joints either. It was very fiddly, not helped as the bit on my Weller TCP needs replacing. M Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 15, 2014 Share Posted January 15, 2014 I am sure that you will have seen pics like this one on some of my other threads. Not saying that it is great but just the way that I do it. More to try and help others than yourself. Weller irons are great and I have used them very much in the past but for modellers the CPC soldering station mentioned on my Mustang thread is well worth a look at. This is what I actually use at work now. The spare bits are only about £1. Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 15, 2014 Share Posted January 15, 2014 Forget the above post Martyn as we have probably crossed over here. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 15, 2014 Author Share Posted January 15, 2014 Thanks Martin I have redone the wheel wells tonight and have a bigger gap - probably very similar to the amount that you have got showing. I'll do some photos (they are now more circular as well) but they look much better. Martyn Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 16, 2014 Share Posted January 16, 2014 This is an actual Curare wheel well. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 17, 2014 Author Share Posted January 17, 2014 That looks like a much bigger gap then mine. I'll photograph it later and upload. Thanks Martyn Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 20, 2014 Share Posted January 20, 2014 I have been away for a few days. The gap on the Curare is actually about the same as on the larger wheel shown earlier. You may get away with a little less than this, but I am not using a separate battery here so it is large for the sake of safety. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 26, 2014 Author Share Posted January 26, 2014 A bit more progress. I haven't had much time this week/weekend, so not much to report First - the wheel wells. Take 2 - and this is what they look like now.. Not quite as circular as I would like but at least there is a reasonable gap now... The TE extension in the centre of the wing and at the joint between the flaps/ailerons and wing tips have now been added. They have been faced with 1/32 ply. The extension at the root has been built from 1/16 ply inlaid into the false TE. This gives a good strong surface, this carries the wing mounting bolts. You can see where I have inlaid ply in between the upper and lower sheets to support the TE. The core is solid balsa.. It feels very strong. I have added the ply end caps to the wing tips. These were fairly straightforward but I have used 1/32 ply instead of 1/16. I think it will be OK, I am trying to save weight now, this wing is starting to feel very heavy. The last couple of evening have been spent filling dings and generally sanding now the wing surface to get it ready for glassing. This was followed by a general vacuum round to get rid of as much dust as possible The servos and U/C were removed, the electrics covered and the 60g cloth has been put down on the upper wing surfaces. This was much more difficult than I imagined, the temperature in the workshop is the wrong side of cool and the Zpoxy was a bit on the thick side despite warming it gently for half an hour before mixing.. I'll leave it for 48 hours to really harden then I'll do the under surface of the wing. One decision I need to make is whether I should add a wing joining tape down the centreline. I am still a bit worried whether it will be strong enough.. More to come... Martyn Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 27, 2014 Share Posted January 27, 2014 The wells look much better. A point about the torque rods. Do they run in brass tubing? If so, keep them well oiled from the start or they will seize up with rust. I learned this the hard way and now only use tube as an inner and outer. (see Curare pics). Is that Z-poxy specifically for skinning since I have not noticed it in the shops? I always bring freshly skinned parts straight into the warmest part of the house to cure for at least 24hrs since there is little odour to worry about. I would hope that an extra wing joining strip is unnecessary since that is how my Mustang is built but a piece of skinning cloth over the centre would not do any harm. BTW, you should have done the underside first so that the LE overlap is out of sight as per iron on film. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 27, 2014 Author Share Posted January 27, 2014 Thanks Martin. I feel much happier with the wells now as well... Do you put a layer of glass cloth in the wells? It would make sense although I am not sure about convention. The torque rod bearing tubes are nylon and hopefully are still free after the glassing session My worry with the centre panel joining is that the plan shows a 12mm balsa doubler across the centre 2 bays only. No ply... I didn't like that and added spruce doublers instead going out 2 bays, but I am still very nervous about this.. As you say a 25mm strip wont do any harm.. OK on the sequence for applying the cloth. The top overlaps the LE and folds under by about 6mm. I was planning to slice the bottom off flush with the apex of the LE so that it wont overlap to the top. However, I will bear in mind your suggestion for next time. BW Martyn Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 27, 2014 Author Share Posted January 27, 2014 I have just been into the shed and am very pleased to see that the resin has cured very nicely Martyn Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 27, 2014 Share Posted January 27, 2014 That`s good news. I use 320 grit production paper to sand off the excess cloth. I often fit a disk of balsa or depron to the top surface of the wing in the wells and/or a coat of resin or acrylic. I omitted the dihedral braces altogether on the P51 since they were so small as to serve little purpose. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 27, 2014 Author Share Posted January 27, 2014 Hi Martin Regarding the braces, that was my thought as well.. I just wanted to spread the load in a nice linear manner. The only way that I could do that was by using tapered Spruce spars. I suppose time will tell if it is strong enough. However, I suspect that my Magic with my piloting skills is likely to have a much harder life than your P-51 with your piloting skills. Fact of life... BW Martyn Quote Link to comment Share on other sites More sharing options...
Sam Wragg Posted January 28, 2014 Share Posted January 28, 2014 Hi Martyn I'm in the process of getting my Magic back up in the air. She last flew back in 1996. Reading this thread has brought many memories flooding back concerning the build of Magic and how difficult it was. Originally Magic was fitted out with a Super Tigre 61RE to which i fitted a OS Pump & Carb unit. I have a brand new OS.61RF ABC-Pumped what i bought many many years ago but never got round to using and now in the process of fitting this engine to Magic I Never fitted the Snap Flaps to Magic for the reason I lost a Curare when they pulled out on its test flight with the resultant demise of the model. When i get some photos i will up-load them and hope they assist you in you build BTW What i remember she flies on rails Regards Sam Quote Link to comment Share on other sites More sharing options...
Bill Michie Posted January 28, 2014 Share Posted January 28, 2014 Welcome to the newest/oldest Pattern group in UK, Sam...................... I'm enjoying the fun & flying, without any pressure, stress, or anything else that goes with "trying" to fly F3A at any sort of competitive level. (& yes I know I wasn't very good anyway!) Regds, Bill PS: just bought a S/H RFP that I'm cleaning up as a "let's see if it works" project.................. though I favour the short-stroke engines for "period" sound & speed............ Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 28, 2014 Author Share Posted January 28, 2014 Hi Sam Thanks, it's been a long haul so far. With the exception of my Puppetteer which took me 5 years to complete, this has been ongoing for nearly 8 months and is my longest build and there is still a good bit to go. Hopefully though it will be complete by the end of February.. Regarding Snap Flaps. I have actually installed these on my AcroWot to see how I can get on with them. I consider that model dispensable as I have wrecked it 3 times in 12 months, one more wont hurt it much more. (PS come and join us (UKCAA) officially - it wont get any cheaper..) Martyn Edited By Martyn K on 28/01/2014 17:18:53 Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 28, 2014 Share Posted January 28, 2014 Have never heard of the term `snap flaps` before although I have been using the Curare type for years. I call them drag brakes. Look again at my Curare pics and you can just about see the tinplate straps soldered to the tubes. They are well and truly pegged through to the brakes and the only thing likely to fail is a solder joint but at least they will stay attached to the wing. Even with no servo slow they can be deployed at full power and although I was a bit dubious at first I have never had one come adrift. They are great for landing in a small field even if you do not use them in manoeuvres. Martin Mc Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 28, 2014 Share Posted January 28, 2014 P.S. My previously YS63 powered standard size Dalotel now sports a rather more retro ST X61RE with a Webra Dynamix, tuned pipe and TK fuel pressure system a la Curare. Goes like stink! Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 29, 2014 Author Share Posted January 29, 2014 Hi Martin You are far more experienced in these matters than I am, but I thought that the concept of Snap Flaps was that they work in harmony (coupled) with the elevators, ie elevators go down, flaps go up and vice versa. There is a standard mix on my Futaba transmitter to enable this. I thought that Phil Kraft was one of the first users of these coupled Flaps - they were used on the Slik Fli Best wishes Martyn Quote Link to comment Share on other sites More sharing options...
Bill Michie Posted January 29, 2014 Share Posted January 29, 2014 Think I recall reading, that Hanno had various variations of the Flap system, including some with airbrakes & some without................. The "snap-flaps" seems to be the simplest solution, mostly used coupled with elevators for sharp square corners, and slow landings (these days can be mixed in with up ailerons a la "crow flaps" for landing apparently). Worth trying out anyway, esp with modern mixing trannies. Bill Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted January 29, 2014 Share Posted January 29, 2014 I was referring to the Curare type with 1/3rd of the area going upwards to create a brake counteracted by the down going part to give a neutral trim change and I believe used to slow the model in a dive. Prettner may have switched these in with low throttle since he had a rather clever Tx. for the time. Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 29, 2014 Author Share Posted January 29, 2014 Hi Bill Here is a repeat video posting from my AcroWot wing build thread I haven't had the opportunity to try it yet. Weather and field are collectively too poor. Martyn Edited By Martyn K on 29/01/2014 14:16:40 Quote Link to comment Share on other sites More sharing options...
Martyn K Posted January 29, 2014 Author Share Posted January 29, 2014 Hi Martin Ah - I hadn't realised that was the way the Curare flaps worked Thanks Martyn Quote Link to comment Share on other sites More sharing options...
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