Use a square to set up the bulkheads F1, F2, and F3. Make sure they are able to fit in the right place with no interference from glue blobs. If there is excess glue, carefully chip it out, or remove a little bit of wood from the affected area of the bulkhead using sand paper or a knife.
Now it’s time to attach the struts. If you use Titebond or epoxy you will have to clamp the joint tightly while it cures. If that’s OK with you I won’t try to stop you, but I believe medium or thick CA is the best way to do it. The glue is stronger than the wood in any case, so the strength of the glue isn’t an issue.
There are lines on the plywood doubler to show where the struts go. Put the struts and F2 in place and use a square to make sure everything will fit where it belongs.
Set F2 aside. Line up the strut assembly on the the etched template and attach it with medium or thick CA. Attach the struts to only one fuselage side.
Place the fuselage side strut side down on the table and place shims under it so it will lie on the table without rocking. Place the other fuselage side on top of it with some 1/8″ balsa sheet in between the two fuselage sides. (In the next step below, this shim will hold the fuselage sides far enough apart to allow room for the two wing saddles to come together without interference.) Carefully line up the outer perimeter, and pin the two fuselage sides together. You can make a pin fit diagonally at the front in spite of the plywood doublers.
Place the other strut assembly on top of the fuselage sides. Line it up with the one that’s already attached and clamp the two wing saddles together using clamps or clothespins. You’ll want to place the parts so the wing saddles are off the edge of the table.
Due to inaccuracies in the placement of your fuselage side doublers or in the construction of your struts, the second strut assembly may not exactly match the etched lines where it is supposed to attach to the fuselage side. This is OK, because the thing that really matters is that the two wing saddles need to line up with each other to provide a straight platform for the top wing.
If the end of the front strut is going to interfere with the placement of Bulkhead F2, or if the rear strut protrudes outside the fuselage side at the dashboard, use a utility knife and/or sanding block to correct it, so everything will fit.
Once you have it right, attach the second strut assembly with medium or thick CA and press firmly.
Use medium CA to attach a piece of 1/4″ triangle stock 1/4″ behind the front of the fuselage as a backing for the firewall. An etched line is provided to help you place this piece. Also using medium CA, attach the 1/4″ x 1/4″ hardwood servo rails in the locations marked on the etched locations. There is a short rail and a long rail on each fuselage doubler.
Now that you have two complete sides with struts attached, we can build the fuselage. Lay one fuselage side on the table with the wing saddle hanging over the edge of the table. Use a square to attach F2 and F3 with medium CA. These parts should be exactly perpendicular to the fuselage side.
Use medium CA to add 1/” balsa triangle stock behind F2 and F3. (Pretend the servo rails are present in the following photos. I didn’t follow my own instructions, but they should be there already.)
Because of the step caused by the wing saddle doubler, attach the triangle stock behind F2 in two pieces.
Lay the other fuselage side on the table, and set the side with the attached bulkheads on top of it. When everything is lined up attach the bulkheads with medium CA. Add 1/4″ triangle stock behind F2 and F3 like you did on the other side.
The top and bottom edges of the firewall F1 will be sanded to an angle due to the slant of the top and bottom of the fuselage. You can get a head start by carving the bottom edge with a utility knife.
Apply Titebond or epoxy to the mating surfaces.
Put F1 in place and clamp firmly. Make sure F1 is aligned vertically on both sides.
