andy watson Posted October 26, 2009 Author Share Posted October 26, 2009 Well another proper building update. The spats have long been causing me trouble working out how I was going to do them. The issues were getting the angles right, making them robust enough to survive and how to make them accessible if required. The plans don't help here- they simply show the outline if the final result. I have considered all kind of methods- from building a strip wood frame and then sheeting them to carving the whole unit out of a solid piece of balsa. I have looked at shock absorbing foam sections and deliberate weak points. In the end I started by making 2 plywood profiles of the top of the legs and tack glued them to the underside of the wing. I then mounted the oleos and spats. Then using a carbon fibre strip to pin the spats into the correct position: The angles involved meant that my original plan of sheeting this were a total pain. I spent a couple of hours messing around trying to get templates cut, but it was obviously just too awkward. In the end I decided to build it up using 1/8" sheet cut into strips. I now have to sand it to shape, which should be reasonably straightforwards, the biggest difficulty will be not trailing sawdust through the house and getting into trouble! The dining room table will need to be cleared soon, so back to the office, but you get a nice idea of the stuka with its spats on! Quote Link to comment Share on other sites More sharing options...
andy watson Posted October 27, 2009 Author Share Posted October 27, 2009 The legs have been sanded to shape, a simple job with some coarse grade paper. There were a few gaps and bits which needed some filling, so that was done with lightweight filler and then the whole lot was sanded with a finer grade of sand paper. Once all that was done they were given a coat of sanding sealer. The whole leg and spat assembly was then covered in glass cloth and given a single coat of poly C to glue it in place. There is a possibility that despite my best efforts there might be some tidying up to do on the covering- this is because it is very awkward to get to some areas with the wings. It definately needs some trimming! I am back in the workshop, so space isn't as great as it could be. Hopefully it will be fine once I get into the front room and can move the wing around more easily. The poly C will need another 8-10 coats over the next few days. Quote Link to comment Share on other sites More sharing options...
andy watson Posted October 31, 2009 Author Share Posted October 31, 2009 Well another couple of short steps have been taken. Once dry I gave the spats a good look over. There was an area of glass cloth about the size of a 10p that seemed to have bubbled up on the bottom of the spat, so I cut that out and replaced it. 5 coats of poly C later and it's invisible to all but the most picky of inspections, and being on the underside of the spat it shouldn't get the closest of inspections! One of the things about poly C is that although it does dry in about an hour, it appears to continue to harden over the next few days. So I left the legs alone for a couple of days, then went over the legs and spats cutting off the drips and trimming the glass cloth neatly. I will give them a proper sand smooth and add another couple of coats, but wanted to get some other bits done before finishing them off. At this point the spats & legs were simply tack glued into place. I had used a ply plate at their top to ensure a good glueing surface for fixing to the wings. The plans suggested using silicon sealant to do this, and as I happen to have a lot in the garage it seemed like a good idea to me! So I carefully filled the gap with sealant to hold the leg in place better and smoothed it off. The last job I have just finished is adding the support fairing at the gull wing joins. This had given me a few headaches on how to do it. I wasn't keen on Johns method of sanding strips of balsa to shape as I thought it might be easy to damage the wings. I had a vision in my mind of some plastic strip that would do the job, so went to B&Q for a look. After about an hour of wandering round looking at various options and ideas- I didn't want to ask, as I thought explaining what I wanted would take too long!- I found some oval conduit that was hinged to a square backing (as opposed to the full oval tube). I bought that and trimmed the oval half off. Then it was simply a case of glueing it in place. The legs just need the fairing adding, which I will do tomorrow with lightweight filler, then I will coat in poly C and give the legs their final couple of coats. Oh, a secret money saving hint- B&Q are selling 50ml of cyano and activator for a tenner. I wanted to check what I pay before buying any, but it works out more than that and no kicker. Quote Link to comment Share on other sites More sharing options...
andy watson Posted October 31, 2009 Author Share Posted October 31, 2009 Well one problem I hadn't anticipated. The legs have a fairing on them where they meet the wing surface. I had a simple plan to build this up with light weight filler, but when I tried it I couldn't get the stuff to stick to the poly c'd surface of the wing or leg. This means I couldn't build it up. My instinctive reaction was to reach for the silicon again, but I am slightly reticent as understandably the paint will not stick to it. I think I should be ably to poly C over the silicon, and then the paint will adhere to that, but if it doesn't work I am left with a mess at a late stage in the build. I am thinking I will have to buy some modelling clay or something, but I would really appreciate any ideas, since I imagine I will have exactly the same problem with the wing fairings on the fuselage. Anyway, the day has been spent keeping young Oliver quiet, so only steady building. I have run over the bits I wanted to with poly C- except the legs/spats because of the problem above. I have just started having a go at the ailerons and flaps. Like so much with this build it isn't straightforwards- these are the features that make the model so interesting though! The controls hang below the level of the wing, rather than flush. Most of the hinging had been done earlier as they are built into the flaps/ailerons, but they need attaching. This is not easy as each wing has 2 flaps and an outer aileron, and all must line up. The slots have all been cut out, and I am using epoxy for strength. I decided the middle aileron was probably the best place to start rather than either end as it is only held in by a single hinge- a lot of flexibility for movement and fitting if needed. It looks like it is in place ok, but I am a bit worried- this is a job that could screw everything up. Quote Link to comment Share on other sites More sharing options...
Dave Wilson Posted October 31, 2009 Share Posted October 31, 2009 Hi Andy I may have something that could work on the fairings. It's "Artist's Past", used on paintings to build up texture. I have used it several times to fill in scratches and dents on my trainer, it sets hard and obviously is easy to paint over. Depending on how much is needed on the fairings it might do the job. (it can be built up over several layers) You know how to contact me if you want to give it a try. Oh! Oliver should be getting his "Membership Card" soon! Will give Ian a shake to hurry it up Regs Dave Quote Link to comment Share on other sites More sharing options...
andy watson Posted November 1, 2009 Author Share Posted November 1, 2009 Cheers Dave- I was starting to think I was all alone here! Olivers card arrived a few days ago, so leave Ian alone! If you stick the paste in the car I will borrow it next time I see you if that's ok. Quote Link to comment Share on other sites More sharing options...
Dave Wilson Posted November 1, 2009 Share Posted November 1, 2009 Will Do. I have 2 types so will bring both. Pics of tonights Night Fly on gallery, good turn out Quote Link to comment Share on other sites More sharing options...
Klippy Posted November 1, 2009 Share Posted November 1, 2009 Hi Andy, try B&Q again, there's a sealant that painters use (as opposed to artists) comes in long tubes, sticks to just about anything, and, you can paint over it! Quote Link to comment Share on other sites More sharing options...
andy watson Posted November 3, 2009 Author Share Posted November 3, 2009 Cheers Tony- do you mean decorators caulk? I think I have some of that kicking around somewhere too. If I remember correctly B&Q were selling the tubes of sealant/caulk for about a fiver each, or "trade packs" of 6 tubes for about £6! Anyway, a really progressive couple of days. All the flaps and ailerons are in place. This isn't a simple job on a stuka as not only do they hang below the wing, but they are also connected together. Worse, the trailing edge is not straight, but angled in 2 places. Each section (the 2 inboard ones are flaps, the outermost one is the aileron) has a piece of metal tube embedded into the wing. Now I use a piece of wire slotted into the tube to join them. The hinges- most of which are already attached to the flaps.ailerons are made from proskin- available from Mick Reeves. It's a very tough piece of board- the thickest sheet (which I am using) can be used for making custom horns etc, thinner sheets can be used to sheet models. The hinges are shaped for scale and to keep the gap between the wing and control surface. The end is drilled and a piece of wire that is again embedded in the control surface is passed through the hole to form the hinge. I'm sure the details are further back when I made them. Anyway, the detail of the gluing is above. The time was taken was in getting them all lined up. The wires holding the seperate sections together needed to be bent to a specific angle to match up with the trailing edge, but it then needed fiddling with to try get a smooth action. I then discovered that the hinges were not set to 90 degrees to the surfaces (this is correct, not a mistake!), and this caused them to ride along the wire hinge slightly when moving. Because I had tried to be as accurate as possible when making them, this meant they were a bit tight and I had to widen the gap on each one. Time consuming and fiddly, but they all work smoothly now, and look really good. They do not really show up well on the photos though! I might be wrong here, but I am really confident that I will be able to work the pushrods in the scale manner that I am looking for. Rather than hanging the servo arm out of the bottom of the plane I want to try keep it inside the wing, and just have a rod exiting the win to connect to the flap/aileron. If you see a photo later with the servo arm protruding through the wing please don't mention it! Quote Link to comment Share on other sites More sharing options...
Stephen Grigg Posted November 3, 2009 Share Posted November 3, 2009 Im pouring over an SE5A wing plan to work out the materials needed ,but your latest updates have taken my energy away.Good progress Andy,I think Ill lay down for a while now Quote Link to comment Share on other sites More sharing options...
andy watson Posted November 3, 2009 Author Share Posted November 3, 2009 Poo. Just lost my last post. I had some time left, so decided to mount the posts for the dive brakes. The brakes and parts were all made a long time ago- in fact I used them as test pieces for using the poly c. I had spent a long time measuring the bits as accurately as possible, as I have to have 3 pins acting as hinges that all rotate in perfect alignment. Unfortunately I have since realised that measurements made carefully several months before have a nasty habit of being completely inaccurate later on. I decided to do the outer posts first, and worryingly the measurements seemed perfect. I glued the posts in place. Using a couple of pins as hinges (split pins or bolts with nyloc nuts will be the permanant hinges) I rotated the brakes whilst watching the central hinge- the hole rotated perfectly on its axis. The central mounting posts were harder to fit. I needed to cut slots in the wing to glue them in. The holes had to line up horizontally and vertically through both mounts and the central hinge. I marked it up carefully, cut the slots and crossed my fingers. Again they went in perfectly. I put pins through as hinges again and was delighted as they rotated smoothly. It will be fiddly to get the push rod through the wing to the servo without cutting big holes in the wing. Careful measuring will be the order of the day, and if I cock it up I am only replacing the access panel rather than the whole wing sheeting. Quote Link to comment Share on other sites More sharing options...
andy watson Posted November 7, 2009 Author Share Posted November 7, 2009 Realised the last update showed the dive brake in place. The wing mounted posts are shown below: I took Tonys advice and tried decorators caulk for the fairings on the legs. It worked a treat, and according to the instructions it's overpaintable. The control horns have all been fitted on the flaps and ailerons. By my reckoning the wings are now virtually finished and ready for painting. The pushrods need making for all the control surfaces and the dive brakes. The radiators need glueing to the wings, but because they need painting inside I thought I would glue them after painting- or at least after priming. The spats/legs need a couple of extra coats of poly C once the caulk is dried. Still plenty to do on the fuselage though! Oh, the landing light needs finishing off too. Oh, and the leather bindings on the legs need doing. Hmm, still plenty to do Quote Link to comment Share on other sites More sharing options...
Kelly Posted November 7, 2009 Share Posted November 7, 2009 Fantastic build blog Andy . I wonder if the dive brakes will slow it down in a dive ? It would make it even more worth the effort of fitting them if they did . Look forward to your next posts Kelvin Quote Link to comment Share on other sites More sharing options...
Emil Benson Posted November 7, 2009 Share Posted November 7, 2009 coming along nicly Andy Quote Link to comment Share on other sites More sharing options...
andy watson Posted November 7, 2009 Author Share Posted November 7, 2009 Cheers guys- it is nice to get a bit of input along the way. As for the dive brakes, I haven't seen another blog on this build but John designed them to be fixed and not working. When you look at the Zirolli build blogs and discussions they all agree the dive brakes are ineffective, although maybe throwing full flaps on might have some effect. Once it's in the air we will have to do a few tests. Quote Link to comment Share on other sites More sharing options...
Klippy Posted November 8, 2009 Share Posted November 8, 2009 It's all down to Reynolds numbers I think Andy, Model sized bits trying to work in full sized air! Coming nicely now, have you weighed her recently? Quote Link to comment Share on other sites More sharing options...
andy watson Posted December 2, 2009 Author Share Posted December 2, 2009 Well I have been a bit remiss lately on keeping the blog up to date, mainly because I haven't done a huge amount of building. I think the reason for this is acceptable though- a one month old baby takes over the whole house! I have done bits and pieces though, and keeping these up to date on the blog is awkward- if I don't have long to build then I would prefer to get something done rather than writing about it! Having said that not only do I enjoy blogging the build the help I get also means the thing might actually fly at some point in the future! One thing I have been doing is messing with my new air brush and compressor. It's pretty good, but I need practice! I have been painting some of the small bits and pieces that need painting seperately to get practise with both the air brush and the warbirds paints which need thinning and catalysts adding to make them useable. I have painted all the servo covers, the dive brakes and the underwing radiators. They have been given a primer coat and then a coat of RLM 65 - the blue colour used on the undersurface. The radiators are obviously not empty, and contain the actual radiators inside. I decided to paint them black, and thought they would probably leak bits of oil around, so took the opportunity to try use the air brush to add a little effect. It will be inside the radiator, so no one will probably ever see, but I know it's there! Just for the record a 10 pound hungry bundle of squawking turned up half way through and this update took an hour! Quote Link to comment Share on other sites More sharing options...
andy watson Posted December 2, 2009 Author Share Posted December 2, 2009 One little detail I have completed is the landing light. I had a look at a number of photos and checked the colour scheme as it needed painting before the cover went on. Checking detailed photos I could see there is a raised section around the clear cover, so rather than just gluing a clear sheet over the gap in the LE I made one that fitted into the space and used 1/64 ply to make the panel around it. The clear plastic was cut from a coke bottle. Once all the paint was dry I simply glued my preassembled cover in place. Quote Link to comment Share on other sites More sharing options...
andy watson Posted December 2, 2009 Author Share Posted December 2, 2009 Again using some of the close up photos I have in the books I got a good look at the front of the chin radiator. I used that as a template to add some scale detail rather than leave it open or blank. It's incredible how you can get yourself completely thinking along a set of lines, and manage to ignore a much simpler solution. Here is a picture of the cowl up to now: According to the plans the chin needs to be extended 2 cm further. This takes it over the removeable section of cowl. I have spent a lot of brain time working out the best way to build that 2cm section of chin on the removeable section of cowl. Then I realised that whilst it was convenient to build the removeable section back to the former F2, it was actually completely unnecessary. So I trimmed off 2cm from the back and glued it in place. The removeable section is now a bit smaller, and I can build the rest of the chin straight onto the fuselage. That seems to make a lot more sense, especially as I imagine that area will draw the eye on a stuka, and a good job will be easier to achieve in this way. I am tempted to remove the ply sheeting around the chin and the balsa sheet/block off the bottom and extend them 2cm forwards, but I think I can match them. Time will tell. There has been a bit of chopping to get it all fitting properly- mainly because I have got an engine larger than recommended. The next bit is to build up the rest of the chin and it will be done! A little tidying and the front is complete.Edited By andy watson on 02/12/2009 18:56:25 Quote Link to comment Share on other sites More sharing options...
Stephen Grigg Posted December 2, 2009 Share Posted December 2, 2009 Love the attention to detail you are so patient Andy very impressed.Do you enjoy building more than flying or do you enjoy both equally.I enjoy renovating a model that hasnt flow. n for a while.Its nice to get it back in the air where it belongs. Quote Link to comment Share on other sites More sharing options...
andy watson Posted December 3, 2009 Author Share Posted December 3, 2009 That's a question I have asked myself several times Stephen. I think the truth is I fly to give me an excuse to build! I am certainly disappointed in myself that my flying hasn't progressed as much as it should this year. Whilst I am more consistent than I was when I did my A about a year ago, I don't really do anything new. I did pile in a travel air practicing rolls (and getting them wrong!) but I spend far too much time flying circuits rather than stretching myself. I am sure the weather and family have had an effect, but there is also the fact that the models I build need scale flying is also an excuse not to try new things! The strange thing is that it's not a fear of crashing that stops me- I can afford the time/money to replace any ARTF losses, but there is a definate fear of loss on the DVII and the stuka will be as bad! I prefer watching someone else fly them to flying them myself! Quote Link to comment Share on other sites More sharing options...
Stephen Grigg Posted December 3, 2009 Share Posted December 3, 2009 I think when you have Such superb quality models like these 2 you have built its very comfortable watching an expert fly it on your behalf.You can enjoy watching it fly without the worry of having to control it.You can take so much more detail of your model flying in also.The worrying bit is when the expert says " would you like to fly your model,"you just have to give it a go Quote Link to comment Share on other sites More sharing options...
andy watson Posted December 3, 2009 Author Share Posted December 3, 2009 The thing is I am in no hurry to complete them- and can't resist just tinkering a bit more! The big advantage to this is it does stop my other half complaining too much about me having too many planes!! I don't build them fast enough! It's the club AGM tonight, and I might take it out for inspection. Quote Link to comment Share on other sites More sharing options...
Stephen Grigg Posted December 3, 2009 Share Posted December 3, 2009 They can only be very impressed Quote Link to comment Share on other sites More sharing options...
andy watson Posted December 3, 2009 Author Share Posted December 3, 2009 Turned up with the stuka tonight to be told next month is bring a model night! I wish they would say what is coming up at these club meetings a bit better. Anyway, the stuka went down well. I got the usual bits and pieces of faults pointed out- too much slop in the wheels, cheap snake used in the elevator, cheap control horns used. Apart from that it was fine! The question of weight was brought up, and I mentioned the original plan aimed at 5kg, but I knew mine was heavy- just not how heavy! One of the guys had some scales with him, so I risked public humiliation and stuck the stuka on- 4.5kg. Thats pretty good I think when you consider the siren, 8 servoes, working dive brakes etc etc were all in place. The engine is 900g (from memory), but I think the only heavy thing left is the cockpit- and that is really down to me getting all detail obsessed again! I think final weight will come out at about 6kg. This thing might get off the ground after all! Quote Link to comment Share on other sites More sharing options...
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