Delta Foxtrot Posted May 11, 2014 Share Posted May 11, 2014 Thank you for the quick reply Peter. What you have said is crystal clear and confirms my suspicions. I like the idea of omitting the lower wing caps trips to allow for the lower surface curvature. I will make me a new R3 and crack on with the wing build . cheers david Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted May 12, 2014 Author Share Posted May 12, 2014 David. I wouldn't bother making a new R/3. Just keep going. It will not make any difference to the model. Quote Link to comment Share on other sites More sharing options...
Delta Foxtrot Posted May 12, 2014 Share Posted May 12, 2014 Posted by Peter Miller on 12/05/2014 07:51:20: David. I wouldn't bother making a new R/3. Just keep going. It will not make any difference to the model. Peter, I am sure you are right, but I did it any way. It was the work of a few minutes as had I made a set of templates to cut around. I just have to sort out a couple of bits and I should be able to start building the wings sometime this week. Work being a neccessary evil I only manage an hour here and there in the evenings so progress is not that rapid, but it is always nice to start to see things comming together. I managed to aquire a copy of your Tequilla Sunrise plan through ebay. I took a liking to this design when I saw a photo of it in your book. I will have a go at converting it to electric at some point. cheers david Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted May 12, 2014 Author Share Posted May 12, 2014 Tequila Sunrise is a small model. Flew well. Miss Lizzy is a bigger version of the same model. Not a perfect enlargement but very close. Quote Link to comment Share on other sites More sharing options...
Delta Foxtrot Posted May 13, 2014 Share Posted May 13, 2014 Posted by Peter Miller on 12/05/2014 18:36:07: Tequila Sunrise is a small model. Flew well. Miss Lizzy is a bigger version of the same model. Not a perfect enlargement but very close. Thanks for the heads up Peter. This looks a much better option, very tempting and probably my next build. I did a little more work on the CAP20L last night with the recut outboard R3. I have glued in all of the main wing ribs after laying down the l.e. sheeting and cap strips at the t.e. plus the two at the aileron spar / l.e. I assumed that the capstrip under the aileron spar must sit underneath R3 rather than be butted up to R3, which means that R3 sits on top of this and the wing t.e. capstrip. The result is that the wing is slightly raised at this point relative to the inboard ribs R3, R2, R1's. This is probably not a big deal if both wings are built in the same way, but I just wanted to check that I had not misinterpreted the drawing. david Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted May 13, 2014 Author Share Posted May 13, 2014 There is a capstrip under the rear of the R-3s. This is like the capstrips under the ailron spar and aileron leading edge.Then the solid training edge butts up against it when the top capstrip is fitted. There the capstrips under the aileirn ribs and the 1/4 sheet aileron trailing edge butts up against the ribs and aileron capstrips. Edited By Peter Miller on 13/05/2014 18:31:12 Quote Link to comment Share on other sites More sharing options...
Delta Foxtrot Posted May 13, 2014 Share Posted May 13, 2014 Posted by Peter Miller on 13/05/2014 18:30:18: There is a capstrip under the rear of the R-3s. This is like the capstrips under the ailron spar and aileron leading edge.Then the solid training edge butts up against it when the top capstrip is fitted. There the capstrips under the aileirn ribs and the 1/4 sheet aileron trailing edge butts up against the ribs and aileron capstrips. Edited By Peter Miller on 13/05/2014 18:31:12 Yes and the R3 just inboard of the aileron has both the aileron spar cap strip and the wing trailing edge capstrip under it if I have read the plan correctly. Because the rib is not flat bottomed aft of the spar this raises the trailing edge a little when pinned down. Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted May 14, 2014 Author Share Posted May 14, 2014 Just build it the way that you have it in your photo. IT is the way that I did and It works! Quote Link to comment Share on other sites More sharing options...
Delta Foxtrot Posted May 14, 2014 Share Posted May 14, 2014 Quote Link to comment Share on other sites More sharing options...
Delta Foxtrot Posted May 14, 2014 Share Posted May 14, 2014 Peter, I built the wing with the lower aileron spar cap strips as in the above photo and as a result I have a wing panel with a twisted trailing edge and tip washout. I will have to start again, but would like to make sure I get it right next time. It appears to me that there is an issue with the plan as drawn. Either I have the aileron spar underside cap strip under R3, in which case it sprags the rib up or I butt it up to r3, in which case it will bend under the chord wise cap strip on the lower side of r3 and this will look odd. I am tempted to modify the aerofoil to be flat from the spar to the trailing edge so that I can just build on top of all the lower surface cap strip, there is not much curvature. Sorry to be a pain with this, but I would really like to sort out my mistake with this. david Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted May 15, 2014 Author Share Posted May 15, 2014 The last part of the rib is virtually flat so there will be no significant difference between a rib supported on the trailing edge capstrip and a rib supported on the aileron spar cap strip. I built mine that way and every one else seems to have built their models that way. Any very slight differences that there might be can/will be compenstated for by the fact that the aileron is moveable. Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted May 15, 2014 Author Share Posted May 15, 2014 The last part of the rib is virtually flat so there will be no significant difference between a rib supported on the trailing edge capstrip and a rib supported on the aileron spar cap strip. I built mine that way and every one else seems to have built their models that way. Any very slight differences that there might be can/will be compenstated for by the fact that the aileron is moveable. Quote Link to comment Share on other sites More sharing options...
Delta Foxtrot Posted May 15, 2014 Share Posted May 15, 2014 Peter, Logically I think that you are correct and there must have been another factor at work with my wing build. I did have some concern that my nice SLEC balsa building board had curled up and I did clamp it down with battens to make sure it was flat, but I may need to rethink that. Anyway after a short inquest I will have another go. thanks for your help dave Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted May 15, 2014 Author Share Posted May 15, 2014 Personally I use 12" X 48" chipboard shelves covered with a double layer of cork tiles. Lay these on a flat bench and they are straight. Quote Link to comment Share on other sites More sharing options...
Delta Foxtrot Posted May 15, 2014 Share Posted May 15, 2014 Thanks for the info, I wondered what you were using in your pictures. I had been using the slec balsa board on a flat surface, but not permenatly bonded down to it. I built 3 planes on it and they came out true, but since then it has been stored against a wall and that has not helped it's cause. I will have a look around for some shelving before starting the next attempt. Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted May 15, 2014 Author Share Posted May 15, 2014 The pictures are taken in my "Studio", a sheet spread over my bed! You can buy cork tiles on EBay if you can't get them locally. Any Homebase or toehr DIY store will have the shelves. I have two so I can build both wings at once. Quote Link to comment Share on other sites More sharing options...
Delta Foxtrot Posted May 16, 2014 Share Posted May 16, 2014 Peter, I took your advice and made myself up a board like yours plus I bought some MDF for a pound to fix my slec balsa board to. I gave the back bedroom/modelling room a clean up and am ready for another go at that wing. Dave Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted May 16, 2014 Author Share Posted May 16, 2014 Well, you should ahev no trouble now. Good luck and have fun. peter Quote Link to comment Share on other sites More sharing options...
Patrik Johansson 1 Posted August 18, 2014 Share Posted August 18, 2014 Hi Peter, Looking forward to build the CAP 20L as my winter project. I would like to fit a 4-stroke in to her, have both a Saito 40 and a 30. What would you suggest? It seems that the 40 should fit fine inverted. The weight is 260 resp. 300 grams. All the best Patrik Quote Link to comment Share on other sites More sharing options...
John Warren 2 Posted November 21, 2014 Share Posted November 21, 2014 Peter, My Cap20L built to your design has just had its maiden flight and I am very pleased with it. I have got about 2 years flying experience , not an expert . Once trimmed out , It is a nice stable aeroplane that I feel confident with and can start learning to fly aerobatics. It appears to be difficult to stall ! so far. Thanks for a great design, I'm a happy 72 yr old. I did convert to electric power. John. Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted November 22, 2014 Author Share Posted November 22, 2014 Hi John. Glad to hear that you are so happy with the CAP 20L. It is a nice model and the stall and spin characteristics are really excellent. Two reasons for this. A low wing loading and forward CG. You will certainly be able to learn aerobatics with it. I am particularly fond of four point rolls, also known as hesitation rolls. She does the crispest one I have ever flown. Quote Link to comment Share on other sites More sharing options...
Delta Foxtrot Posted June 18, 2015 Share Posted June 18, 2015 Peter, I parked this project, but I now want to crack on and complete it. One of the areas I had problems with was the false leading edge. How do you get the shape of the bottom of the false leading edge correct with the wing pinned down? I am happy enough with shaping the top with a razor plane as I can see this, but the underside is another matter. I would be grateful to you if you can pass on any tips for how to do this. I wondered if you pre shaped this before glueing, but if the wing is tapered in thickness this is not so easy . Perhaps I could build the wing and sheet the top and the remove from the board before shaping the bottom of the false leading edge and then attach the lower sheeting, but I am concerned that removing the wing before the leading edge d box is in place could lead to warping. I confess that I need to read the plan and build article again, but I remember this being an issue for me last time I had a go at this. Dave Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted June 19, 2015 Author Share Posted June 19, 2015 The 1/8" leading edge just needs a slight chamfer on the bottom before gluing it to the ribs. IT does not have to be a perfect match to the ribs. The glue will fill any slight miss match if you use Aliphatic resin or PVA. The 1/8" leading edeg capstrip goes on after the wing has been lifted from the board and is shaped then. The result of usung this type of leading edge is that you get a rebate which is an amazingly strong joint and yet it is easy to shape. Quote Link to comment Share on other sites More sharing options...
Delta Foxtrot Posted June 19, 2015 Share Posted June 19, 2015 Thanks for the quick reply Peter. You make it sound simple and I guess it is. I haven't built with a false leading edge before but it does look like a very good method. Hopefully I will get it right this time. Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted June 19, 2015 Author Share Posted June 19, 2015 It is simple. I am lazy and always try to work things in the easiest posible way. Quote Link to comment Share on other sites More sharing options...
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