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Graham Davies 3

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Everything posted by Graham Davies 3

  1. Another Focke. Slightly anonymous, I may add yellow 16 markings, but I’m keen to get it in the air. warbird’s replicas, so you all know what this is. Ready to do battle with my similar provenance P51B and Yak 3. If I can just work out how to fly all 3 at once.. Great design and kit, as always. He’s clever, that chap Wills… Graham
  2. You’ll need to add a bit more “structure” to the wing to support the retracts, and a bit to the wing join to absorb the take off and landing loads. I use hardwood spars for the main spar, a secondary spar and liteply ribs up to the retracts. This prevents twist and gives a hard point to attach a ply plate for the retracts. I then make sure these spars are joined to tough points in the fuselage. Easy enough if you plan it out. Be aware, you need to add a bit of complexity if you want wheels! it’ quite possible though. I fly off a quite rough strip and both the spitfire and my regianne have no problems. let me know if you need any details. Regianne for reference… Graham
  3. Yes, it works really well. B&Q varnish doesn’t damage the foam, and dries reasonably hard. You’ll need 2 or 3 coats. With the spitfire I sprayed a coat of silk over the top of the paint too to give it a nice even sheen
  4. I haven’t yet got them as tough as a balsa or veneer skin, but mine are reasonably tough. The spitfire is covered with lightweight glass cloth applied with b&q water based varnish. It’s cheap and easy and provides a reasonably tough surface. The underlying foam is soft though so it’s still easy to mark. For the replacement wing on the p51 I used foamboard and left the paper on the outside and then glass clothed over this. It’s a little tougher still. Certainly into practical scale model territory. i think there may be further gains trying heavier cloth and possibly some tougher resins, but so far results are good.
  5. I think this is an interesting point Martin. Most people have a perception of foamboard or depron. Whilst the techniques may be different, there is a whole spectrum of outcomes from simple and functional up to full scale beauties. For me, it’s been like the light of building fun has been switched back on. Again, and shamelessly as I’m really proud of it, my depron 1/6 scale mk1 spitfire…
  6. Thanks Peter, Credit goes to the venerable Richard Wills. This model was his original p51 that had hundreds of flights under its wings. I acquired it as part of Richard’s ‘moving house garage sale’. It had a solid fuselage, but the wing was toast. It’s now got a foamboard wing, electric conversion and reborn as a fling and flopper. Launches from a dolly if there’s a little breeze, or a good heft if there isn’t. Flies great, and looks good in the air. Be better when I’ve detailed it.. Graham
  7. Maiden flight for this yesterday; Richard Wills' original P51B, as featured on his website. I acquired this in the great 'moving house, do you need any of this stuff' sale. It was part way through a repair, and seemed too good to bin. It's been in my garage for a couple of years. The original foam wing was toast, and went in the bin. It was also configured for IC. I built a wing from foamboard with B&Q 6mm pine spars, covered in glass cloth applied with B&Q water based varnish. the refurbished fuselage is covered in PVA/ brown paper, in usual WR style. The whole lot is painted in Valspar emulsion, matched (not too well) to a strip of the original painted covering. As yet, I've not added any detailing. That's because I'm off work this week, and the weather was great yesterday. Power is a 4250 540kv motor turning a 14x10 on 4S packs. Don't know about the weight; not light. Around 5lb at a guess. I made no effort to keep it as light as my usual foamboard constructions as I want a model to handle a breeze. No wheels, it's a fling & flop model. The radiator gives a reasonable grip, if a tiny bit too rearward to be really comfortable. So I made a dolly... It needs bigger wheels to cope with our strip, but works OK. Maiden was uneventful in the extreme; she didn't appear to have enough groundspeed on the dolly, but just as I was considering aborting, she rose gracefully and climbed out flat and level. Apart from a bit of right rudder, no trim was needed... Graham
  8. Small things, up close. Big things, far away...
  9. The only problem is when sanding, the inevitable remnants of UHU on your fingers makes a lovely black mess that takes ages to get off...
  10. This stuff is good too; seems a bit easier to curl without cracking: https://www.diy.com/departments/vitrex-classic-5mm-foam-laminate-solid-wood-underlay-panels-9-76m-/5011204608997_BQ.prd
  11. The whole project for the 1/6 scale spitfire including servos, retracts, wheels and a load of detailing stuff from Mick reeves was about £250. The actual airframe part was probably less than £40...
  12. Sorry, 6mm square PINE. I obviously lost interest half way through that word! Give it a go Mike; it's dead easy, costs peanuts, and with a bit of lateral thought, produces great results. I flew these two yesterday; both look great in the air, fly incredibly well, and are considerably lighter than a standard build. This results in really decent flight times. The Regianne is 55" span and I get over 8 minutes in 4S 3300; the spitfire is 74" and I get 5 minutes from a 6S 3300 pack. Graham
  13. Hello David, I've followed with great joy your exploits at the Coup. I've a fair bit of experience using depron in various forms to make both sports and scale models, although all electric. However, I see no reason why we can't adapt for IC. There are a number of techniques and routes you can make use of. I started by viewing the excellent and inspiring videos on the FliteTest website. These fantastic chaps really make anything seem possible. For me though, their approach of using foam board entirely was a bit restricting, so I have taken ideas from FliteTest and used traditional modelling techniques as well. What I now do is reasonably similar each time: I tend to use laminate flooring underlay. This is available from B&Q in the UK and comes from 2 main sources and is either black or white. The white comes in 3,6 and 9mm, I think the black just 6mm. For your usage, I'd go with 6mm anyway. You can use foamboard from art shops, but the paper adds a lot of weight, and not much else! I tend to remove it with an iron, which takes ages. However, my latest build it's staying on the outside to add a bit of ding resistance. So once I have my preferred foam, I cut out the LOWER wing profile. Cut the UPPEr profile around 10mm deeper chord (to allow for the camber) There is a slight 'graining' to depron where it is easier to bend and less likely to crack in one direction than the other, but there's not much in it, to be honest. I make 4 or 5 ribs, not many more and don't worry about spar cut outs etc at this stage. The lower panel need to be 10mm shorter chord than the overall wing at the leading edge to make space for a few strips to make up the LE. If your wing profile has any camber on the underside, gently curve the wing panel by gently dragging it across the edge of a table. This will preform the foam so it accepts your ribs more easily. Then add your main spar. If the model is a lightweight, a few thicknesses of foam will do, but I generally add more strength here. My current favourite (cheapskate) method is to use 6mm square pin from B&Q, one top, one bottom. If you have balsa, 1/4 square is probably ideal. Start by gluing the lower spar to the foam profile at around 25% chord. Then notch your ribs (top and bottom) to match the spar location and glue them in place from the spar back. I don't do the front yet. It's easier to do this when the rear section is dry as you can use something like UHU POR as a contact adhesive and pull the foam up to the ribs whilst keeping the rear section weighted to your board. Then add your top spar, and some spar webbing. You can use foam in between the spars, or balsa glued to them conventionally. Balsa is stronger, naturally. Add a dihedral brace (I use ply, probably 1/8") and fit to one wing. I use a second spar as it helps support the skins and hold the airfoli. It's not there for strength, so you can fit it between your ribs. Add this at around 60% chord, and you can use a couple of thicknesses of foam. I understand this wing is 3Ch, so you don't need to worry about ailerons. Curve your upper skins as per the lower, but a bit more aggressively. Take your time or you'll crack the foam. I sand the insides of the trailing edges top and bottom to get a thinner trailing edge. Then the tricky bit; contact adhesive on all the contact points, and take a deep breath and whack it on! Line up the trailing edge as there will be a bit of overhang at the leading edge, which we'll manage later. Keep the wing pressed hard against the board (with a bit of packing under the leading edge of the prifile) and it should stay straight. You now have most of a wing (probably within an evening!). You need now to trim the leading edges to align. I now add a few laminates of foam for the leading edge, and sand to shape. You can use soft balsa for a bit more tougness. You can do both wings and join last, but it's tricky to clamp the dihedral brace. I use various methods, depending on the size. You can join once you have finished one wing, but before adding the top skin to the other. Makes it a bit of a handful, but you'll get a good strong join. Or split the skin and cut a section out where the brace is and add this bit back in after joining. It makes little difference to strength. to be honest. So you now have a wing. I have covered in PVA/ Brown paper with success (although not great if you leave the paper on foamboard as the heat can loosen and bubble it). My new favourite method, and probably most suitable for you, is to glass cloth using 25 gsm cloth and water based varnish from, again, B&Q. (I don't work for them, btw...). This is a great method and super easy. You just paint the stuff on. A couple or three coats and you'll have a good tough finish. You can then paint with your choice of paint, but I'd avoid solvents as they will probably still damage the foam underneath. You will obviously then need some fuel proofer. I don't have much experience here, but some have used the same water based varnish I hear with some success. I have used it over emulsion to protect the finish, but my models are electric. The wings are quite strong, but not as stiff as a balsa wing. Don't let this put you off trying; it costs peanuts if it doesn't work. I hope that helps David, please feel free to drop me a line, or have a chat. Some pics of the wing of my Regianne. I did this a year or so back and have got better since, but this model is still flying. Graham Graham
  14. Yours is still a decent size. This is 1880mm. All B&Q foam. Flies great.
  15. It should fly well LM. Enjoy the journey of discovery that foamboard gives you! I warn you; it's really addictive. Now I know how to scratch build practical scale models based on drawings, there's no stopping me. Spoiler alert: my next project is a 1/6 scale Bf110. That's around 108", or 2740mm in new money. Target weight is 12lbs. Should fly on a pair of 4S packs, and look suitably imposing... Graham
  16. I think there are a few too many variables for me. Snakes need to be secured at each end, but allowed to 'flex' to a degree in between. This is how they compensate for different amounts of expansion due to temperature changes. Any differences in length, mounting etc will mean different degrees of compensation and therefore elevator twist. For me, I think i'd keep it simple and join the elevators. As Eric said; these things are a bit important!
  17. Thanks Eric, Simon. Eric, no current projects, apart from my daughter's kitchen! Planning a big twin for later in the year. Simon, I've followed most of your builds, and my cap is thoroughly doffed. I love your approach, but it is quite different to mine. My models are aimed at being 'practical scale models' suitable for rough fields and rougher pilots (me)... I'm intrigued by your structures though. I've gone heavier on my spars, but I think I may be over-engineering a little. However, as my 74" spitfire came out at 8 pounds and some change, I think that is fine. Much lighter and the turbulence we get in some wind directions would seriously reduce the comfortable flying days. I felt the slight tickle of inspiration to consider a jet though, and that is always risky fir my hangar space... Graham
  18. Fascinating. The youtube link took me here: Not sure I like the sound, but it's still massively impressive in a relatively modest sized model. Graham
  19. Or scratchbuild. The world then, Rodney, is your lobster... Ki45 anyone? Graham
  20. It will be fixed! I've already doubled the chord of the ailerons and got some control back. I've increased the dihedral which has also helped a bit. I think it's CG sensitive and at the moment is at a 'safe' forward position. I think this is making the elevator insensitive so it's hard to fly 'bank and yank'. There may be some masking of the tail too due to the huge cockpit, so I may give him a scalping! Graham
  21. B&Q deliver the underlay. It's in reasonably large packs for about £20. Once you get hooked (and you will!), you'll soon go through it! Talking of Grandsons; this is what I built for mine. Looks OK, flies like a pig! Graham
  22. Looking great L-man, I use 3mm for cladding. I find it more than enough, is easier to form, and obviously half the weight. I use bits of 6mm if I need to support to sand down to for joins, etc. That way when It's all done you can get a nice smooth finish really easily. How are you going to join/ seat the wing? You'll need some fairly hard points if you are bolting on, and beware of the compressibility of foam. I tend to reinforce an area between the firewall and the TE with 1/32 ply so I can support a reasonable wing seat, and have something to key in a wing bolt plate and LE dowel plate. This also adds strength to the motor mount. Otherwise, glue the wing on and you won't need to worry! Graham
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