P40F Warhawk for Scalecombat! The plan You have to enlarge the plan. Use the stab span (or rather half the span, as only one stab-half is shown). The stab span (half the span) should be 163mm (6.4inch). Buildup The P40F is builtup completely in foam, using a newer technique that allows for a faster buildup. It should be repeated that foam is a good material to build fighters from, as it takes lots of punishment, and is easy to repair time and again. To be able to build from foam, you need a foam-saw. It is not that hard to build one on your own. Please see other instructions on how to make such a saw. The wing Making the wing is not that hard. You need two pieces of white-foam. See figure and table for exact measures on the two pieces.Mark centrelines on the two sides of the two pieces. Then make the two cutting-templates 20 and 21, from plywood or something similar. On these you should makr the centreline, and the ten vertical lines, on both sides of the templates. Give each vertical line a number, starting from the leading edge, and working backwards. Attach the templates (20 and 21) using needles, to one of the foam-pieces. Be careful having template 21 angled upward, as on the plan, to accomodate washout. Then cut along the upper side of the template, from the leading edge and backwards. Please use extra weights on the foam, to keep it steady. Two persons are normally needed to cut. The trick is to pass the vertical lines of the template, in the same order. Please count the passed numbers (vertical lines) aloud - this helps! Then turn the piece of foam upsidedown, and cut along the bottom of the template. Then do exactly the same to the other pice of foam, and be very careful to make a left and a right wing-half! You could draw an arrow on the upper side of the foam-pieces, to show what direction is ”forward”. Doing this, you easily see that you have one of each. Covering Now it is time to cover the wing-halfes. You need the scrap-foam left over when cutting the two halfes, so don’t throw it away! Glue the balsa covering, to make one big sheet. The easiest way of doing this, is to use tape, to tape the sheets together, and then dip glue into the taped section. When you have a big sheet, cut out the pieces you need to cover the wing. Add an extra half-inch just in case. First you cover the bottom. Put the covering in the bottom scrap-foam. Add white-glue in long strings onto the cover-sheet. Donät add too much glue, it adds weight! Then place the foam-piece on top, and the top scrap- foam. Then attach weights, to press it all together. Do the same to the other wing-half. Let it dry over night. Aileronlinkage When the bottom covering is dry, you can continue with the aileron-linkage. The size of the aileron can be adjusted for you to use the aileron-linkage you want. Cut up a passage in the foam, to allow for the linkage. Don’t forget that you will add an extra spar to hinge the aileron in, at the trailing edge of the wing. Then cover the upper surface of the wing, in the same manner as you did with the bottom covering. Join the wing-halfes You now have two covered wing-halfes, and you should sand the leading edge, the trailing edge at the aileron, the wingtip, and the wing-centre, to get flat surfaces to attach glue. Then attach the leading spar, the trailing spar at the aileron, and the wingtip. Use PU-glue. As PU-glue expands while drying, you should tape along the spars/wingtip, to avoid sanding excess glue afterwards (you save quite alot of work by doing this!). With the extra details added, you can now join the wing-halfes. First sand the wing-centre sides, to close fit. The dihedral is supposed to be some 10-12cm (4inch), measured with one wingtip flat on the surface. Use PU- glue to join the halfes (and tape). Sanding What remains now, is some sanding and filmcovering. Finally you could add a throw-hold under the wing, to hold when launching the model. An easy way to do such a hold, is by making it out of 3mm plywood, and just cut a slit in the wing, and attach it using PU-glue. Add sanding-paper on both sides of the hold, to give a good grip when the model gets full of oil. The fuselage make the fuselage out of thicker foam (blue or pink-foam). You will need two pieces for your fuselage. See figure and table on measures. Be careful to mark centrelines, as these are used to cut the fuse. Again, be careful! Then make templates 1-5 out of stronger paper, or plywood. Note that you will need two template number 5. This one is not marked on the plan, but it is easily made, as it outlines the wingsaddle. Make these tao templates (5) to also cut the backside of the scoope. Mark centrelines on all templates. Templates 1-4 should have clock-marks. (1-12). These are used to count aloud, when cutting (just as with the wings). To be able to get into the inside of the templates, a slit should be cut. Make it along ”clock-line” 2 on templates 1 and 3, and along clock-line 10 on templates 2 and 4. Wingsaddle The first you have got to cut, is the wingsaddle. Use the templates 5, and attach them to the leading piece of foam. Be careful to attach them exactly according to the centreline. Then cut the wingsaddle, and the backside of the scoop. Do the same to the trailing piece of foam. To cut Use needles templates 1 and 2 to the leading piece of foam. Be careful what is up and down, and in which direction the slit is attached! Ensure that the slit is large enough for the cuttin giwre to pass. Once again, two persons are neede to cut. Cut through the piece of foam, to just outside of the slit. Then cut through the slit, exactly at the same time. Then start cutting the inside, the same way, counting aloud. Note that the clock wil be backwards for one of you. Keep a steady pace. When again at the slit, cut out from the inside, at the same time. Then start cutting the outside. When this is done, you should have a leading piece of your fuselagem waiting to be sanded. Then do the same to the trailing piece of foam. Note here, that it is harder to cut, due to the differences in template size. Be careful to save the top scrap of foam, from the leading piece. This piece is later on used as a part of the cockpit (part 13). Join the fuselage You are now able to attach the pieces 6, 7 and 13, which makes the fuse. Use PU-glue, and tape. Be sure to make a straight fuselage - check this before you attach the glue, and afterwards! When the glue is dry, you can sand the fuselage to shape. You find sideviews of the cockpit and engine- nacelle on the plan. You can use an ordinary saw at first, and then sand it to proper shape. Then prepare for stabilizer and fin. Attach them to the fuselage using PU-glue (please note that the elevator does not have to be inserted when attaching the fin). The elevator should be atached afterwards, but check that this is possible. Then make the engine-mount out of plywood and add spruce-spars to generate extra surface for the glue. Prepare the engine-mount in the way you like it. Personally I use blind-nuts, to make it easy to install the engine.You make your engin-mount after how you want to install your engine. The one on the plan, is made to have the engine in approximately 30 degrees of angle, from upright. You attach the engine-mount using PU- glue. Use lots of glue here, as this is a critical point. The engine should be directed somewhat nownwards, and to the right (1-3 degrees). Covering You now have a ready-to-cover fuselage. You can cover it using brown-paper and wallpaper-glue, or you can choose to cover it using an iron-on tex of some sort. Iron-on tex makes a lighter model, but brown-paper is in general tougher than tex. Then paint the model, but be careful not to add extra weight! Ad a shark-mouth if desired, but note that it takes lots of time. Installation The engine used in the prototyp is a Fox 15. This is a heavier engine, which made the prototypy nose-heavy. Miniservos where used, and a mini-accus. In spite of this, the prototype was heavy, most probably due to the heavy brown-paper covering, and excess paint. There is plenty of room for the radio, if you want to use standard equipment. Good throws to begin with, are 0,5mm (1/5 inch) up/down on the elevator and aileron. Later on you can adjust to the throws you want. Testflight Before you take-off, you should check the following: Is the CG right? It can be located somewhat in front of the recommended, but definitely not behind it. Does the engine run perfect? To take off using the P40 should not be any problems, but the model might have wrong trim, depending on how you built it. You can make the first throw over high grass or the sort, to make the crash easier - if you crash. The P40 should be easy to fly, and land. As usual, keep up speed in the landing, and let it fly all the way down. Then you could practice some dogfight, and later on you simply must show up at a contest, to feel the atmospere!! Martin Elmberg Data P40F Warhawk Scale: 1:12 Engine: .15 Span: 94cm Weight: 800-1200g Part nbr. A B C D E 6 260 50 50 100 50 7 408 50 50 70 80 14 430 80/62 140/41 20 20 Measure-table, for the three differnt kind of foam-pieces needed. (All measures in millimeter). For the pieces 6 and 7, measure A is an exact measure, while the others are minimum-measures. For the two wing-cores (14) A- C are exact measures, while D-E are minimum-measures. Please note that measures B-C differ on the two shortsides, as the wing is tapered. Centrelines are drawn onto the pieces of foam, using the above measures. List of numbered parts: 1. Fuselage template 1 2. Fuselage template 2 3. Fuselage template 3 4. Fuselage template 4 5. Fuselage template 5 6. Leading fuselage, foam 7. Trailing fuselage, foam 8. Fin, 4mm balsa 9. Stabilizer, 4mm balsa 10. Elevator, 4mm balsa 11. Engine-mount, 3mm plywood 12. Rubberbandsdowels, 5mm 13. canopy, foam 14. Wingcore, white foam 15. Leading edge spar, 10x15 balsaspar 16. Wingtip, 15mm balsa 17. Wing trailing edge, 4x10 balsa 18. Aileron, 6x25 trailing edge spar 19. Wing covering, 1mm balsa 20. Inner template wing 21. Outer template wing Materials used: Light foam (white foam) Thicker foam (blue or pink foam) 4pcs 1x100x1000mm balsa 1pcs 4x100x1000mm balsa 1pcs 15x100x1000mm balsa 1pcs 3x100x1000mm plywood 1pcs 5mm dia dowel 1pcs 10x15 balsa spar 1pcs 4x10 balsa spar 1pcs 6x25 trailing-edge spar