tomatically for the way the length would de- crease as the sides were pulled in. By the way, since we’re not making a Scale Masters project, “close enough” will be a key idea to remember. Finally I imported the front and rear view and scaled it to match the top view. This gave me the shape for the formers I would need as well as the scale dihedral. Most programs will allow you to print a PDF and/or tile the output. Since I have a large format inkjet plotter, I printed three copies of the 3-views and checked the re- sults, but you could have them printed at your favorite office supply store. My wing area worked out to be 93 square inches (close enough). I was shocked at how big the fuselage would be. Very roomy inside com- pared to the micro Pattern models I had done in the past.
I was also shocked at how big the nacelles turned out. Placing one of the E-flite fans on the side view, the scale outline dwarfed the little guy. Because I had what I felt was sound reasoning behind me regarding the wing loading and area, I decided to ignore the nacelle size difference. We’ll have to wait and see how that turned out ...
So far I had invested about an hour and a half, including the Internet search. Now that I had workable 3-views at the right size, it became time to convert them into crude plans. This is where “close enough” re- ally shines! The first thing to do was make sure that the left and right sides of the top view were identical. In fact, it turned out that the right wing panel was 1⁄8 inch more span than the left.
To compensate, I would need to pick one side as the master. I chose the left (larger) side, since it would allow me to build on the right side by simply moving one rib a little farther out from the root. I began marking the centerline and then LE and TE outlines I would use for building, being sure to make left and right identical.
This marking of lines is necessary because the enlarged 3-views show the pixels as large squares, making a very wide line. Sim- ply dividing the line down the center with a straight edge and pen took care of that for me. After the outline was in place, I needed to mark the rib positions and the location of the spar, then of the ailerons. Aileron sizing was done according to the TLAR principle of
Calculating size and area is easily done in any spreadsheet program. If you would like the spreadsheet the author created for his A-10 to adapt for your model, e-mail him
andy@andykunz.us and he'll send it right out.
model aircraft design (That Looks About Right), with a smidgen of round numbers— they’re 3⁄4 inch wide to fit some stock I had handy and that’s about the same as the scale ailerons would be, although mine are more of the span than scale would have been. The stab was “designed” the same way. On to the fuselage side view! First it is necessary to select a reference (datum) from which all other measurements are made. I chose the straight line which is the bottom of the aft fuselage, and drew a line all the way forward and aft on it, and the LE of the wing as the fore/aft reference point. There is no need to try to have a 0° incidence line; we are looking for a reference for construction. The bottom of the fuse on the A-10 is remarkably straight, and the LE of the wing is an easy transfer to the top view. By referring to the front and rear views, as well as some photo- graphs, I decided to make the bottom of the fuse squared off, just like many of the other
micros I’ve built, and to have the top of the fuse (which is also quite straight for much of its length) as a curved sheet. This would be light, strong, and simple to build. On the side view I was able to mark off a top line which included only one change of angle, and that point corresponded nicely with what could become a hatch. This meant I would need a former at least at that loca- tion. I also wanted one at the LE and TE of the wing saddle for mounting purposes, and one at the LE and TE of the stab and the front of the battery hatch up front. After lo- cating these, a few more were added to keep things straight (or curved, as the case may be).
Next, I translated these locations to the top view, and then drew rectangles that matched the outlines onto a sheet of paper. The rounding for the top side was copied off the front and rear views, and the curves for the formers between them were roughly in-
Print several copies of the 3-views (above left). One is for notes but otherwise untouched, and the other two can be cut up to make templates for the parts and/or building over. Follow standard construction techniques that you are
FLYING MODELS
familiar with. Andy marked the 3-view (above right) to locate ribs, spars, and LE/TE lines. The inner ribs were just rectangles that were sanded to airfoil after assembly.
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