The main spar is made by gluing two 1⁄8
the proper shape (above). The ribs (below) slide onto the 1⁄4 spar is glued to all the ribs.
×1⁄8-inch balsa strips to each other using the pins as a guide to get × 1⁄4-inch spruce spar and then the top main
BICh-3 but when I came across the three views for the BICh-7A, I decided to build the BICh-7A model. I was not disappointed. The model is a great flyer, stable, yet quick to fol- low control inputs. The small rudder is sur- prisingly powerful. The construction is so simple that even a beginner could build this model. The only slightly unorthodox part of the plane is that the elevons are hung below the trailing edge of the wing as per the original BICh-7. This is not the first time that this kind of mount- ing of the control surfaces was done. Prior to BICh-7 using this kind of setup, the German Junkers company used it on some of their planes, like Junkers Ju-52. Since I wanted the model to be more scale I hung the elevons as per the original BICh-7. If you do not care for this kind of mounting, then at- tach the elevons directly to the trailing edge of the wing. Cut out all the ribs. Cover the drawing
with a clear plastic sheet. Pin the ribs to the building board. No need to use any shims or jigs. Slide and glue in the 1
⁄4 ⁄8
spar into the ribs. To make the curved main spars, take 1
-inch balsa sheet and cut the 1 ⁄8 × 1 -inch size spar. ⁄4
× 1 -inch spruce ⁄8
⁄4 -
inch strips. Take the two strips and smear water base glue on them and join them to- gether to get a 1
into the slots in the ribs. Glue it in. Glue on the trailing edge sheeting. Again, using 1
Being wet it is easy to bend the spar to fit ⁄8
-
inch balsa sheet cut a strip for the sub lead- ing edge. Glue it to the ribs. Sand the edges to the contours of the ribs. Flip the wing on its back. Glue in the bot-
tom main spar. Before the bottom trailing edge sheeting is glued on, glue the plywood plates in the location as shown on the draw- ing. The plywood will hold the hinge horns. Glue on the bottom trailing edge sheeting.
×1 -inch plywood strip. This strip is there to
be used as a no load bearing support for the vertical landing gear strut. This strut will be riding up and down freely inside the 1
⁄8 -inch
The top trailing edge sheet (above) and the leading edge spar (below) are glued to the ribs. Most of the model’s construction is contained within the wing. See text for method of covering the balsa.
hole. Cut out the elevon surfaces. Now, sand the wing and elevons. If you are going to use Junker style mounting of elevons, then take six regular plastic horns and modify them as per the drawing to create individual hinge arms. Temporally, mount six modified hinges to the trailing edge of the wing. Make sure that they all line up in the straight line. Mount un-modified horns to the elevons. Again they must line up with each other and with the wing’s horns. When satisfied, remove the hinges for now. The fuselage is built right on top of the
wing. Cut out all the parts. The fuselage sides are made in two sections. Front sec- tion, from F2 to F9 and the rear, from F9 to the end. Glue the firewall, F2, between the fuselage sides. Glue in 3⁄8-inch triangular stock between F2 and the sides. Make sure that the firewall is square with the sides. Take the wing and draw the center line of the fuselage and the fuselage outline onto the sheeting, top and the bottom. Glue the preassembled fuselage front to the wing. Glue in F9, F10, F11 and F12 to the sheet-
ing. Glue the rear fuselage sides to the for- mers and the wing. Glue the top fuselage 1⁄4- inch balsa cap to the formers and the
FLYING MODELS 19
Sand the sub-leading edge to the contours of the ribs. Glue on the balsa sheeting over the W1 ribs, top and bottom. Glue on all the cap strips. Glue on the leading edge cap strip. Between the ribs W1 and W2, glue in a 1 ⁄2
⁄16
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