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Alan Gorham_

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Everything posted by Alan Gorham_

  1. Cian re the flaps on the Hi-boy; at one time you could buy a "5-channel" foam wing kit as an extra which had flaps. That's where I got the idea from.
  2. MAPP gas (a mixture of Methylacetylene and Propadiene) is good for silver soldering and brazing as it gets hotter than a standard Butane or Propane flame. I've got a MAPP torch and there's no messing about when silver soldering using it. Gets the heat in nicely, so Jim if you have such a device then it'll do a good job.
  3. I've had or got several of the above kits. High Sierra - thousands of flights using a Cox Tee Dee .049 on a power pod. Good flyer but benefitted from a bigger rudder and the wing joining was a bit dubious IIRC. Hi Boy: I currently fly one of these with an Enya .40 SS glow. Great combo but I have fitted flaps for a bit more interest. I think it makes a good trainer as it flies nicely and is tough as old boots. I've also flown it off water with floats on. Lo-boy: Currently fly one of these with an OS .40 FP. It's the Lo-boy 5 with the single flap under the centre section of the wing. Great windy weather model, flaps make it fly so slowly. Again I've fitted floats. Hi fly - had one of these up until a couple of years ago. Had a DC Spitfire 1cc diesel on the pod. Went nicely but again needed a bigger rudder. I've been on a heavy nostalgia trip over the last few years buying, building and refurbing old 70's and 80's kits I never had when I was a kid. I've got a half-built Aeronca Champ in the loft that I bought the Carbon Copy GRP cowl for. I was originally going to make it electric but since becoming more interested in float flying I thought this would make a good floatplane with either a Zenoah 20 petrol of 120 four stroke so I'm having a think about this. All of the models I have experience of are reasonable flyers and the Precedent die cut ply fuselages were an early example of a manufacturer making an attempt at self-jigging construction. I think it worked quite well and the foam wings were pretty good quality too, meaning that the build was quick and reliable, if sometimes a bit heavy.
  4. At risk of sounding prejudiced....I don't use an electric starter on any of my IC engines (Diesel/Glow/Spark - 2 or 4 stroke). They all start by hand and I am happy I will never damage them by use of a starter.
  5. Ok, I'll show you mine! It's new-ish to me - bought off ebay in May this year it had sat in someone's loft for many a year and was covered in bubbly silver tex material. I test flew it like this, found it flew great - perfect for lazy touch and goes and should be lovely on floats too. So I recovered it in Profilm in the scheme you see here. I'm quite pleased with it.
  6. The points/contact breaker are exposed because (a) it's probably the easiest place to fit them onto a front induction engine and (b) you may well want to be able to retard the ignition point for easy starting. I think I'd want about 10% oil in me petrol as a staring point. I've been using Fuchs Silkolene KR2 oil in my older sparkies this year. It has a modified castor in it to allow it to mix with petrol and of course you get the benefits of the castor being slightly goopier than straight synthetic to help maintain a good piston/liner fit and to help the plain conrod bushings and crankshaft journal. The Merco may be OK on a modern synthetic but I remember that the Merco 35 and 29 had plain alloy conrods (i.e. no bronze bushings) and plain (ringless) pistons. If the 61 is the same (I can't remember - I do think it was ringed?) then I would prefer a bit of castor. I'd be interested to hear how you get on...
  7. There were some 'license built' spark ignition engines based on Merco .61s made by a firm from Yorkshire in the early 1980's. It was around the time that the Vintage model movement was getting popular. That particular engine looks like a home conversion. The carb looks to be a Perry carburettor to me. Note that the ignition system you have are points (as you already know), a capacitor (the yellowish cylinder) and the coil (helpfully labelled Micro coil!). Dunham Engineering made a number of repro spark ignition engines around the early 80's era including an Orwick 64 as well as coils and perhaps spark plugs as well. The disadvantages of this system compared to more modern transistorised ignitions are the relatively high current drawn from the ignition battery, the likelihood of strong interference from the system (that gets worse as your capacitor ages) and the susceptibility of the points to the build-up of oil and oxidation on their contacts stopping a good spark from being generated. If you wanted to fly it I would suggest making up a simple transistorised ignition circuit (Google TIM-6) and definitely fit an inline switch operated by the radio between the ignition battery and ignition that will enable you to switch off the ignition in the air if the engine stops. This is because if the engine happens to stop with the points closed your coil will overheat and burn out and they are not very easy to come by these days.... Bet that's more that you wanted to know....?
  8. Well done Andy, just rewards for a job well done. Looks great in the air. I wish the kit was still available!
  9. Rich - great info. I do a lot of water flying and thought it would be a quick job to make some floats for the Atom. However, I had an idea that there might be a degree of experimenting and new techniques to learn. I did think about a hand launch with floats and then if the flight trim seemed OK then go for a water landing. Where is the CG on the Atom (waiting for Mrs to come home with the Magazine...)? Perhaps I'm getting a bit ahead of myself! I'll build the Atom and see how I do with flying from solid ground first. I do enjoy taking off and landing with skis, so perhaps that can be my first experiment before moving onto floats.
  10. Thanks Rich, that's great - confirmed my suspicions. You're right, it couldn't be easier to do. Next question: have you tried an autogyro on floats?
  11. A question, for Rich or anyone else who can help. Rich, further up the thread it looks like you were slope soaring the Atom. Presumably that means you hand launched it? Can you give me more details of the technique involved as I guess it is different to hand launching a fixed wing model?
  12. I ordered a head and the pre-cut GRP parts from Coolwind on Sunday. Delivered this morning.... Been in the loft to check the wood stocks, might have to get some spruce for the blades and mast... Got a spare AR500, 40A ESC and 3s Lipo on hand, so just need a motor and some servos. Then get to WH Smiths on Friday to get the mag with the plan in. Looking forward to this, promises to be an adventure!
  13. I like the stylised open structure - good work with airbrush. It makes me look at the Pushy Cat in a new light. Seemed rather basic and boxy but your scheme gives it depth and life. Good luck with the maiden, it'll look great in the air!
  14. What used to be the distributor MacGregor are now called hobbyplastic and they sell epoxy glass and tufnol sheet in various thicknesses and sizes. I think they sell on ebay too but their website is www.hobbyplastic.co.uk
  15. Fabulous stuff! I enjoyed that.....
  16. On another forum where the BMFA Club Support Officer posts, his response to queries about why the ban is in place is primarily that there will be a great deal more low flying helicopter traffic conveying VIPs.
  17. Steve - yes you guessed right contact adhesive is a one-shot deal. Yes you do one skin at a time. Back in the old days when obechi veneer was more commonly used it was possible to use one sheet of veneer to do both top and bottom in one go, carrying the veneer around the leading edge, but that's not a great idea with thicker balsa sheet. I would say it depends on your wing section if you need to use the outer off-cuts to support the skin while you apply the core to it. You touch the core down onto either the leading or trailing edge of the skin and kind of roll it down onto the skin to ensure full contact between the skin and core. If you have a flat bottom wing section then its easy to do the bottom flat on the bench. I can recommend a book called Radio Control Foam Modelling by David Thomas which goes into great depth on many aspects of using foam - many of them very applicapble to glider models.
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