A combination of lightweight balsa and lightening holes (above left) cut into the ribs ensure a strong and light wing assembly. Three main spars (above
the photograph of the Canova that is shown here.
It did not take me very long to draw the plans for a 30-inch version of this plane. It is the simplest scale model I have ever built. It only took me a few days to build the model. I decided to use the same con- trol setup as on a full-size plane. To do that, five servos are needed—one for the rudder, two for the ailerons and two for the elevators.
On the full-size plane the control surfaces were hung underneath the trailing edge just as they were on the German Junkers Ju-87 Stuka from WW II. I did the same thing on my model. This arrangement gave me more assurance that the control sur- faces would be working in relatively smooth air. This arrangement worked very well on my model.
For some of you who do not care much for the exact scale model, you can simplify the controls setup by attaching the control sur- faces directly to the trailing edge with four nylon hinges. Instead of having separate el- evators and ailerons, they can be combined into one elevon on each wing. I tried this arrangement and it works very well.
Building To help in building the plane, I have
added reference numbers on the plans and shown in boldface in the text.
Select lightweight balsa. Cut out all the ribs. Cut the lightening holes in the ribs (W1), (W2) and (W3). Slide the ribs onto the three ¼-inch square spars (1). Place six 2½ inch high blocks under the spars to keep them level. Pin the ribs to the spars (1) so each rib is 90 degrees to the building board.
Glue the ribs to the spars. Glue the four 1⁄4× 1⁄8-inch top balsa spars (2) to the ribs. Glue on the top trailing edge sheeting (3). Flip the wing and glue the bottom 1⁄4 × 1⁄8- inch spars (2) to the ribs. Prior to gluing the bottom trailing edge sheet in the locations shown, glue the slotted plywood plates (11) to support the hinge brackets (13) that hold the ailerons and the elevators under the wing.
Inside of each plywood plate (11) cut out balsa to create slots. Now, glue this bottom trailing edge to the ribs and to the top trailing edge. Glue the firewall (4) to the ribs W1and W2. Glue the leading edge spar (5) to the ribs and the firewall. Sand the leading edge spars (5) so they follow the contour of the ribs.
right) help aid in the self rigging nature of the wing construction. The bottom trailing edge has also been applied to the main structure.
Glue the battery floor (8) between the fire- wall and the first wing spar (1). The rudder servo is mounted at the back of the battery floor. Glue on the leading edge sheeting (6) to the top and bottom of the wing. At the bot- tom of the wing, glue in the plywood strips (9) to the ribs W1 and W2 to support the landing gear struts. In the rear, cut the rib W1to create a slot for gluing the 1⁄16-inch I.D. aluminium tube (17) to hold the tail skid (14) that will be moving with the rudder. To both sides of the W1 rib, glue the ply- wood doublers (18) to support the tail skid. Glue on the top and the bottom sheeting (12) over the ribs W1 and W2. In the loca- tion shown, cut out the cockpit opening. In- side the opening, remove part of the W1 rib. Glue on all the cap strips (20). Glue in the plywood plates (10) to hold the ailerons and the elevator servos. Glue on the wing tips (7). Sand the wing. Pull in the extension ca- bles from the servo locations to the cockpit. Use 1⁄8-inch medium hard balsa to cut out the aileron and the elevator control sur- faces (19). On top of elevator and aileron control surface, mark the hinge line and cut the control surfaces in two halves. Make the grooves on the inside to accept 1⁄16-inch
Both the top and bottom spars (above left) have now been glued on to the wing structure. Balsa sheeting is used to cover the top and bottom wing leading
FLYING MODELS
edge as well as the center section. The cockpit opening (above right) has been cut and trimmed.
19
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68