Erfolg Posted May 17, 2018 Share Posted May 17, 2018 Whilst painting My Coverite Gee Bee D4 kit, which is taking me a long time and pretty much unsucessful. The difficulty me being rubbish with both Coverite and open structure frame work. I decided to do something else, as an addition, I have been most undecided. one minute doig one thing, then another, eventually deciding to build a kit I had. I have put off building this kit in the past due to it having foam cored wings. It was a surprise that on examination to find no such items in the box. The kit is some +10 years old, a very early laser cut kit, which shows up in that the cutting is great. What has not been grasped, was the self aligning interlocking nature of later kits and the ARTF models. This results in you needing to keep things aligned by CL and other guides. Al;though the instructions suggest that this is not necessary. There are both a set of instruction sheets with photos and a very good plan. Si it is eins, zvei, drie and loss! Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted May 17, 2018 Share Posted May 17, 2018 The Giles 202 is a very pretty little aerobat Erf - should make a nice model. I'm not familar with the kit, what size is it? BEB Quote Link to comment Share on other sites More sharing options...
Erfolg Posted May 18, 2018 Author Share Posted May 18, 2018 BEB it is 48" span. Yesterday I had some problems with the pictures. The finger jointing is not so precise that you can just insert the pieces and glue them, and the result being true. I have been using a number of methods to achieve alignment from straight edges, paper to obtain 90 degrees. The same is true of the formers and side pieces, which is the stage which I have now reached. Progress will now slow dramatically as being pre-electric flight, on any significant scale, it is designed for IC. That is no easy access to load and unload Lipos etc. I am starting to design a hatch which I have seen on a number of Extra type big IC and electric models. Edited By Erfolg on 18/05/2018 20:31:02 Quote Link to comment Share on other sites More sharing options...
Erfolg Posted May 23, 2018 Author Share Posted May 23, 2018 So far the model has gone together remarkably fast. Everything is spot on, no adjustments have had to be made. I have just copied the canopy access as used on many similar models. I now need to order a motor and a few other things. In the meantime i will start on the wings. Quote Link to comment Share on other sites More sharing options...
Erfolg Posted May 24, 2018 Author Share Posted May 24, 2018 Just started on the wing. The spars are balsa, in the past I would have replaced them for spruce items, now, it is a pain, having to travel, or to order them via the internet. So they say as they are. Quote Link to comment Share on other sites More sharing options...
Adrian Smith 1 Posted May 24, 2018 Share Posted May 24, 2018 Very interesting build Erfolg. Watching with interest. I used to have a larger ARTF Giles 202 by Flair/CMPRO and loved it to bits - literally! Anyway nice to see a really detailed build. Quote Link to comment Share on other sites More sharing options...
Erfolg Posted May 30, 2018 Author Share Posted May 30, 2018 Just a few pictures as to where I am now up to. I am pretty impressed, in many aspects of the kit. The first is that all the parts fit and appear to be correct. The second the tabbing system for the wings keeps the wing pretty much spot on. In the past with kits, I have needed to do quite a bit of work to get things aligned, level and so on. Wilth this kit, it does appear to be all that kits of the past and some recent ones have promised, but never delivered. It really just goes together so far. I now have a problem, where I hope and hopefully not in vain, that some one comes up with a solution to my longer term problem. This problem is that I intend using a film covering. The full size aircraft was a all composite, so it seems. From recent experience, the thin film i use will not produce a smooth finish over the stringers. I need to cover this area with something to provide a support, that when covered with film, will look as it possibly could be a composite. I not that ARTF models often get over the issue using a very thick film or a plastic sheave over which the film is applied. At worst i will use 1/32" balsa sheet to achieve a similar effect,. Any ideas? Quote Link to comment Share on other sites More sharing options...
Rich too Posted June 2, 2018 Share Posted June 2, 2018 Nice progress Personally, I’m not bothered about scale but the balsa sheet should work fine. What are you using for power ? Please, not electric ! Quote Link to comment Share on other sites More sharing options...
cymaz Posted June 2, 2018 Share Posted June 2, 2018 Posted by Rich too on 02/06/2018 06:21:41: Nice progress Personally, I’m not bothered about scale but the balsa sheet should work fine. What are you using for power ? Please, not electric ! Plans show a glow motor of some sort...you may be in luck. What do you say Erfolg?? Quote Link to comment Share on other sites More sharing options...
Erfolg Posted June 6, 2018 Author Share Posted June 6, 2018 Oh most defiantly electric! Quote Link to comment Share on other sites More sharing options...
cymaz Posted June 6, 2018 Share Posted June 6, 2018 Posted by Erfolg on 06/06/2018 17:30:02: Oh most defiantly electric! Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted June 8, 2018 Share Posted June 8, 2018 Spot on decision Erf, who wants a slimy aeroplane? BEB Quote Link to comment Share on other sites More sharing options...
Nigel R Posted June 8, 2018 Share Posted June 8, 2018 That went together fast! Looks very nice Erfolg. What sort of power setup are you going for? Re: balsa spars, I have never used anything different, with never a problem. On this size model with a full sheeted wing you could probably do away with the spar completely. Quote Link to comment Share on other sites More sharing options...
Erfolg Posted June 8, 2018 Author Share Posted June 8, 2018 Nigel You are correct, so far it has gone together fast. Particularly when you consider that I have been in Barcelona for 7 days, The similar concept Balsacraft FW 190 took much longer. The one issue with the Lanier kit is that not everything self jigs to a 90 degree angle. Everything else has been spot on. In general there is one part, if one part does the job. Some kits have to many, many old kits seem to skimp on parts. An example is the Sterling kit I built, not enough turtle deck formers or stringers, giving that starved horse look. I have a few non modeling jobs (that means building) to do, so progress may slow quite a bit. Also the Gee Bee is taking some effort to get near to a colour finish. Quote Link to comment Share on other sites More sharing options...
Rich too Posted June 10, 2018 Share Posted June 10, 2018 Posted by Erfolg on 06/06/2018 17:30:02: Oh most defiantly electric! Quote Link to comment Share on other sites More sharing options...
Erfolg Posted June 20, 2018 Author Share Posted June 20, 2018 Thwarted by high wind here in the NW, so no flying today. I have done a little more on the Giles. Now this is where it gets boring for me. I have all the big bits done. It is the details, the small items. The final fitting out of stuff. Quote Link to comment Share on other sites More sharing options...
Erfolg Posted July 4, 2018 Author Share Posted July 4, 2018 All of the major components are now produced. That is the wings, tail group and the body. with the motor in situ. Now it is all about fitting out all of the time consuming bits and pieces, prior to covering, another major step. It is at this juncture that I start thinking very seriously about where the Lipo will go, servo location and the routes for the control snakes. with the CG marked, I then considered where the Lipo needed to be. Much to my amazement, the model was nose heavy, when the Lipo was placed where I had been planning to locate it. That is in the boxed area where the fuel tank would normally go. Placing the Lipo to obtain a reasonable ballance I found that the Lipo would need to be at the rear of the cabin area. Taking the top of it is apparent how shallow the area is here, Also that my old standard servos Futaba S100 & 128 are to tall. This indicates that much shallower servos will be needed. I have considered putting them in the space just forward of where they are presently placed, although the Lipo would need to go further back. Plus there is an issue with respect to the ease of making adjustments and maintenance Edited By Erfolg on 04/07/2018 10:45:47 Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted July 4, 2018 Share Posted July 4, 2018 It sounds like a good reason to put the servos under the tailplane Erf. Ideally a pair of mini or mg micro ones. Quote Link to comment Share on other sites More sharing options...
Erfolg Posted July 4, 2018 Author Share Posted July 4, 2018 I think you are correct Bob. More often than not these days I prefer rear mounted servos. Primarily as the a short push rod can be used. Perhaps my other preference these days is to use the old model Futaba servos, they may not have the muscle of many modern servos. When I am flying, it is not the servos, that betray a poor flight, it is not even the Tx. Quote Link to comment Share on other sites More sharing options...
Erfolg Posted August 7, 2018 Author Share Posted August 7, 2018 It is some time since i have undertaken any work on the model. What with all the excellent weather, which has necessitated maintenance on the models being flown, there is no time to build. Thank God there has been no rain, as I would have had to garden, which would have meant......... Anyway, I have mounted two 9g servos at the back, undertaken a small number of alterations, and nothing seems to have changed? Hmm, how can this be, I just do not get it. I am now pretty confident that the Lipo will be mounted in the region of the CG. Which is very good news from an inertia view point. Although not at all expected. This is with all the big masses other than the prop insitu. I am now thinking about how to finish. At one time this would have been a pretty big model for this ancient electric glider guider, although tiny from a glider perspective. I just do not want to push the weight up. On that basis i may stop short of trying to get that GRP effect that the full size had, being a composite body. I am not sure what to do other than re-enforce the central area as it is structurally lacking, The other thing is to install the wing servos, the cables being in there already. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted August 8, 2018 Share Posted August 8, 2018 Finish, a roll of HK's finest? Erfolg, if I had spotted the servo problem I would have suggested laying the standard servos flat in the shallow area above the wing. A few small cube (ish) HW blocks could be used to hold them in place on a tray or rails. Personally I feel 9g are just too small for this size of model. Alright on a small foamie, but this must be about 3lb of wood travelling a fair bit faster. The old Futaba standards are very well built and have plenty enough strength - I believe their torque ratings - the 9g servos, build quality does not seem as good and I don't believe their ratings. There doesn't look to be much material in the area above the wing. Does the cabin floor form a part of the structure or is that removed with the canopy as a hatch arrangement for changing lipos? Either way I would be tempted to run some 1/8" sheet doublers across the wing saddle area. Quote Link to comment Share on other sites More sharing options...
Erfolg Posted August 8, 2018 Author Share Posted August 8, 2018 I am not sure that I can agree with you Nigel. I have in the past measured the torque of HX 900 and Turnigy 9g servos and the claimed torque is provided, of 1.2 kg @a cm. This compare well with the claimed 1.4kg @ 10.16" of Waltron, then using Horizon/EK Logitrol mechanics. Which was also much the same as the then Linwood, Micron servos et al . When you then consider that many then pretty large 60 powered RC Scale models were using these servos. More often than not with push rods that were often bendy, and often heavy. Using these servos to drive one surface via a short rigid push rod, seems adequate for many what are now seen as smaller applications. Where they can fall short is in that the gears are fragile when compared to many std. sized servos. Even though Karbonite or superior polymeric materials are often claimed. I do have 9g sized servos with metal gears, although often there seems to be one plastic gear in the chain. Plus they are heavy. I do have a number of Futaba S100, 128, 3003, plus Airtronic Sanwa and Daewo servos all of much the same size and claimed performance. Given that weight at the back doe not seem to be an issue I will use probably a S128 for the elevator, all the rest being 9g types. I will be reinforcing the centre section, creating more of a "bath tub" type central region. My own preference is place servos as close to the control surface as is practical with short push rods (to keep stiff). Accepting that there will be a voltage drop in the extension leads. Most if not all the long push rods I have seen have suffered from flexing of either the metal end wires and even the long push rod itself. I do use snakes occasionally, although the only really reliable ones have been Sullivan golden wire or the rods. Most of the competitors have suffered from stickion, or difficulty in securing the ferules at the ends. Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted August 8, 2018 Share Posted August 8, 2018 I'm with Nigel, perhaps I should have been more explicit as there are micro servos and there are micro servos. I would be looking at metal gear micro servos around 12-14 gm with 2 kgcm of torque as an absolute minimum. 9 gm plastic gear servos may be ok on park-fly foam models but I don't think 1 kgcm is up to the job. Back in the day those Waltron etc servos were barely up to the job on a good day using minimal surface deflections. These days models frequently fly faster and have larger control surfaces. Can you not get your hands on some HS225BB, MG14 or similar? Quote Link to comment Share on other sites More sharing options...
Nigel R Posted August 8, 2018 Share Posted August 8, 2018 Erfolg, the "old Futaba standard servos" I am thinking of are S3000 type, ~40g and about 3kg/cm. I believe that 3kg/cm figure. And quality gear trains. I guess my main objection to the 9g flyweights, is the tiny gear trains, I can't see they have enough resilience to use them on something like this. YMMV. Quote Link to comment Share on other sites More sharing options...
Erfolg Posted August 8, 2018 Author Share Posted August 8, 2018 Bare in mind it is now some 15 years since I have retired, probably over 20 years ago since I undertook any meaningful calcs and in the dark ages when I obtained my degree. If we take the classic relationship of L = 0.5*Roe*V^2*S*Cl. then substitute some typical values with those of my model, in this case the elevator. We get L=0.5*1.01*27^2*0.05*0.2 *1.3 taking approx 60 mph and a Cl of 1.3. I do acknowledge that the V*2 is an important value. I get a value of approx 4.78N. I then went on and made another assumption that the CL acted at approx 25% of the chord and that this equates roughly to a cm. I then assumed that the control horn was the same. All for convenance and ball parking everything. then the Torque in Kg becomes 4.78/9.81 = approx 0.5kg. This value is approx 1/3 of the torque available from a typical 9g servo (at the stall). I had refrained from causing controversy, but no longer. The only servo I actually have positive proof of failing in flight was a rather expensive one, often recommended as bullet proof in many mags. All of my 9g failures have occurred on the ground, when i have damaged the gear train. Although I have no issue with most servos, other than some std. Tunigy ones I purchased, where the speed was much lower than quoted, in many instances on smallish models 9g are often adequate. When i read that some models have servos providing 1, 000kg of torque, on 210v I think, could they be over specified? In general the HX900 seem to centre repeatably, provide the torque specified, the weak link is generally shock loading on the gear train. Quote Link to comment Share on other sites More sharing options...
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