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Andy Blackburn

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  1. Andy Blackburn
    > ...forgot to insert balsa infill either side of the R1 central rib to reinforce the centre of the trailing edge. Oh dearie me... However, looking on the bright side, you probably won't notice unless it hits something hard enough to pull the wing bolt out... Other than that minor contrafibulation, though, your wing looks pretty good. > ... so bought crepe bandage which is not the thing I think this is the sort of gauze bandage I normally use (picture's not that good): **LINK** - single layer, non-stretchy. If you can't find any of this, you're better off using 2 oz or 4 oz glass cloth.
  2. Andy Blackburn
    I've added a section to the plan that should hopefully show how the aileron bay fits together. Here are the new bits:
  3. Andy Blackburn

    Andy Blackburn posted a gallery image in Member Albums

  4. Andy Blackburn
    If you think about it, given that we only have one template it has to be a smaller size - if it was larger so that the template could slide all the way to the end rib, that wouldn't be any good because the tip tank would then be a sloppy fit and would fall off. What the builder is expected to do is to make the tip tanks to that size and then use a Permagrit flat sanding tool (or similar) to sand the inside of the airfoil shaped hole until it's a good fit on the tip and fits all the way on - obviously, you can only do this properly after the wing is covered. The tip tanks are then just a friction fit, none of mine (2 models) have ever come off unless the landing has been a bit traumatic.
  5. Andy Blackburn
    I really like that colour scheme - great choice.
  6. Andy Blackburn
    Posted by Peter Garsden on 10/09/2019 08:38:20: ... Thought I would show you some pictures of the servo installation. Incidentally I was wondering if the wing needed the beef of an HS85mg - I think you could get away with something lighter and metal geared as the drive length is short and the torque should not be enormous. I put it to m'learned friend that there are some recommendations for minimum servo torque based on the size and deflection of the control surface and an estimate of how fast it will be flown, positioned near the title block of sheet 1. The recommendations are: Aileron: 2.7 kg/cm minimum Elevator 3.2 kg/cm minimum. You could risk smaller and less capable servos but if you run out of servo torque it'll be horrible to fly - it does happen... A.
  7. Andy Blackburn
    > Does one put the top skin on wing 1 before starting wing 2, or continue with the bottom skin of wing 2 then top skin both wings? - doesn't matter, really. Personally, I'd finish both bottom skins (making sure that all the wiring, etc. is in place) and then add the top skins one after the other. > Not quite clear how to lay out the wing to get the wash out right. As I understand it one puts 2 10p pieces with 2 layers of masking tape under the main spar at R1. Presumably you also pin down the trailing edge of the wing at R1? Yes, add the packing under the mainspar to increase the incidence at the root (which has the same effect as decreasing the incidence at the tip), make sure the trailing edge is flat on the building board all the way along, and the tip rib should also be flat on the board; weight it or pin it, if you pin it you'll have to take the pins out before glueing the top skin on. You can then add the top skin and as long as the TE and tip rib is still flat when you've done it and the 10p packing is still in place, the washout will be correct. > There are then 2 cradles made out of 1.5mm ply to hold the wing tips. Presumably one glues them together... Nope - there's one for each wing tip. You can add some scrap balsa to the bottom as a support if you want. > One then pins the wing tip to the support cradle whilst the glue dries. Well, you don't really need it for the wing because the dihedral is set by the one-piece manin spar and the washout is set by all the shenanigans you did with the 2 x 10p pieces and two layers of masking tape. However, they might be quite useful for supporting the wing during assembly/setting-up the tail surfaces. You don't have to use them... A.
  8. Andy Blackburn
    Pete, In addition to not fitting R1A until you've attached the bottom skin to R1, both R1 and R1A are at the dihedral break and are at an angle (unlike all the other ribs) so need to be angled/chamfered at the edges to fit nicely. Andy
  9. Andy Blackburn
    Many years ago I had a 46FP that did exactly this; it was running on a #8 plug and the only way I managed to get it to run acceptably was: go down a prop size (to a 10x7, I think) up the nitro to 10% adjust the bleed screw by trial and error until the mid-range pick-up was acceptable (I think it was initially running a bit rich, but it was a long time ago), and accept a slightly higher tickover of about 2800 RPM The problem is, it's an air bleed carb - your room for maneouvre is quite limited. Suggest you try the same process and if you want to keep the revs down with a smaller prop (maybe try a 10x6 for the 40), you could always limit the rpm by putting a switched mix on the throttle so that full throttle on the stick is only about 85-90%, or whatever will give you the revs you want (10,000?). Edited By Andy Blackburn on 30/08/2019 08:12:25
  10. Andy Blackburn
    I'm so sorry, perhaps I should have been more specific. What I obviously meant to say was "The printed documentation that comes with it is not good..." Yes, there are a set of free downloadable manuals but they're PDFs and if you don't like looking at manuals on the screen you'll have to print them out, in which case it'll cost you the paper and and arm and a leg for the ink, and unless you get someone else to do it it won't be nicely bound. So, why pay £15 when you can get a comprehensive manual for free? Because it's good value for what it is, and I don't have to print it out myself. And because my printer doesn't do automatic double-sided printing. Just my personal opinion, of course... Edited By Andy Blackburn on 28/08/2019 08:13:34
  11. Andy Blackburn
    Try the Squadron/Signal monographs - most of them are available from amazon, there are a couple of the In Action series (#33 and #126), there an F-86 walkaround and also a "Fighting Colours" series. HTH
  12. Andy Blackburn
    I think making the skin in one piece (for each section that has the same taper - so one piece for the inboard parallel section and one for the tapered outer section) is the only way to get a good finish - each wing skin can be joined and then finish-sanded flat on the bench before attaching the skin. If you try and sand it after its installed the wing, the skin will just bow inwards between the ribs and it won't be flat. I've used PVA & stacks of magazines in the past, but now use medium CA, sticking the spar first and then using a long straight edge to roll the skin down onto the ribs by pulling the straight-edge back towards the TE whilst pressing it down to the skin, then doing the same for the LE. HTH
  13. Andy Blackburn
    Ooh, nice. Will be watching this one.
  14. Andy Blackburn
    Cautionary note: I'm not an expert! However... The X9D is based on a JR case so the ergonomics are really nice; ramp the stick tension up as far as it'll go and it feels as nice as my old JR DSX9. If possible, see if you can have a play with both Transmitters before parting with cash. Documentation is not good for those (like me) who loathe fast-forwarding through videos to get to the part that you want and then missing it. However, this manual Taranis X9D Plus OpenTX User Manual 2.2 helped a lot. HTH Edited By Andy Blackburn on 14/08/2019 08:29:04
  15. Andy Blackburn
    Thanks! The early black and white markings scheme isn't often modelled on Korean War Sabres, it's usually the later yellow bands. And most plastic kits seem to be the later models (E/F) so I thought it would make a nice change. Edited By Andy Blackburn on 13/08/2019 13:07:52
  16. Andy Blackburn
    Nice colour scheme on 4-50.
  17. Andy Blackburn
    Paypal has just informed me that my wood pack has been dispatched, so I thought I'd better get my two penn'orth in before somebody else has the same idea. I'm planning on an F-86A; this one was the first to shoot down a MiG (Lt Col Bruce Hinton, 17 December 1950, Korea). The A model has a much smaller fuselage bulge around the stabiliser (conventional elevators) which shouldn't be a problem, and the canopy windscreen has a V-shape, a bit like the back of a cricket bat. I'm going to have to make a new canopy plug. Dunno what I'll cover it in yet, possibly Profilm (for reasons of speed and practicality) if I can arrange a suitably-sized bank loan. Edited By Andy Blackburn on 13/08/2019 09:55:32
  18. Andy Blackburn

    Andy Blackburn posted a gallery image in Member Albums

  19. Andy Blackburn

    Andy Blackburn posted a gallery image in Member Albums

  20. Andy Blackburn

    Andy Blackburn posted a gallery image in Member Albums

  21. Andy Blackburn
    Posted by Peter Garsden on 10/08/2019 07:22:55: ... I am thinking of putting some lightening holes maybe in formers, the taiilplane, and maybe the fin. Don't want to offend our designer, but there is a lot of wood, and the JP is famous for flying in marginal conditions. Pete - it's up to you, of course, but I think you'll be absolutely fine as long as you use some light wood - by which I mean 6-7 lb cu/ft - for most of the structure, particularly that aft of the wing. And remember that a lot of the wood gets planed and sanded away. It'll fly differently to the smaller JP and should be more efficient, but what you don't want to end up with is something that doesn't carry momentum through manoevres. Just my two penn'orth. A.
  22. Andy Blackburn
    Posted by Monz on 09/08/2019 21:05:11: Busy planning the next build, a quarter scale BF109 E4, and a bit stuck on which section to use. ... At 1/4 scale (!!), that's about an 8.14 ft wingspan and an average chord about 1.32 ft; that's pretty big. However, I'd be inclined to stick with a bona fide slope soaring wing section because the problem with very large models that have thick wing sections is that they're often relatively light, so often end up being a little bit slow. If it was me I'd go for the thickest available proven PSS section (not a lot wrong with E374, but I seem to remember reading that RG15 is designed to work even when thickened up quite a lot, possibly as much as 15% but I could be mistaken), mounted at a reasonable angle on the fuselage with possibly a bit of artistic sleight of hand at the wing root. And washout, of course... HTH A.
  23. Andy Blackburn
    Posted by Andy Meade on 09/08/2019 08:43:35: No problems, I've not printed anything yet. I will either delete the battery box (it's a poor fit for LiFe cells) or modify it heavily to miss the seats and pilots. I'd like to keep the full depth detail if possible as the airframe is a decent size. You could, should you be so inclined, make the battery box but use it purely as an assembly aid - just tack-glue the formers to it and then remove the box as soon as the sides are in place. A.
  24. Andy Blackburn
    (far too big, of course...)
  25. Andy Blackburn
    Posted by Phil Cooke on 08/08/2019 08:13:09: ... Without the drawings in front of me perhaps Andy B can confirm - this is a 1/8th scale model? Yes, it's 1/8 scale (1.5x 1/12 scale) with minor enlargements to wing and tail areas as discussed.
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