Chapter 12 - Step 2

This step involves mounting the canard in the fuselage.

Fuselage Side Cutout June 15, 2002. Once the fuselage was level in all directions I needed to get the canard straight and level. First I worked on getting the canard level in roll. This was really easy and took virtually no sanding of F-22. Next was getting the canard incidence correct. This is very critical to ensure the canard stalls before the main wing can. I used the "G" template (which was made from 3/4" particle board) on top of the canard and then layed my electronic level on top of it. I was off about 1.8° - trailing edge high. This is fairly normal and it took just a bit of contour sanding of the fuselage sides to eventually get it right. This is time consuming and tedious because you put the canard in place, mark where to sand, remove the canard, sand a bit, replace the canard, re-level in both directions, and repeat over and over until correct. You want to go slow so you don't end up with a gap. Of course if you do it would be easy to fill later. Once I got the incidence correct I measured from canard tip to the rear of the fuselage. I was off just a bit - again fairly normal. In the end I needed to add 7 plies of BID to F-22 behind the left lift tab. I now have a canard that was level, straight, and at the correct incidence.

In this picture you can sort of see how the side of the fuselage was contoured a bit for the shape of the canard and to allow for the proper incidence. You can also see the lift tab with a washer and AN3 bolt temporarily holding it in place. The lift tabs from Brock did not come pre-drilled with the #10 hole. So where does it go? The plans show the dimensions for the tab on page 10-2. The hole is 0.6" from the end. However, large drawing M-11 shows the bolt about 0.8" from the end. Hmmmmm. I called Nat and he said to go by the dimensioned drawing in the plans. The large drawing is only a "rough" drawing of reality. So I put the tabs in the drill press and drilled the holes (interesting excercise with limited space and the tabs being attached to the canard). I then put the canard in place and drilled the #10 holes through F-22.

Alignment Tabs June 18, 2002. With my canard in place my trailing edges are 5/16" and just under 7/16" on the right and left sides respectively from F-28. We are supposed to 5-minute epoxy a 1/4" tab to the trailing edge. With the 1/16" spacer that means one tab will just touch the trailing edge and the other will still be a gap. What to do? I decided to make a solid fillet to make up the difference. I used 0.2" 18lb. Clark foam for the tabs (the plans allow for the foam or plywood). I used the foam because it is much easier to shape. Several builders stated they used plywood because they were not comfortable with the foam. My feeling is this part is not truely load bearing - it is only to keep the canard at the correct incidence. The tabs have 4 and 5 plies of BID and plans say you can use it. Anyway, I layered two small pieces of the foam at the bottom of the main tab and sanded to a fillet shape.

Alignment Tab June 18, 2002. Once the tabs were drilled and sanded to shape, I added a little 5-minute epoxy to the bottom, put in place on the trailing edge, added the alignment pin and 1/16" spacer (a couple washers), and made sure the tab was parallel with F-28.

Aft View of Tab June 21, 2002. Here is the aft and bottom view of one of the alignment tabs.

Side View of Tab June 21, 2002. Here is the same tab from the side.

Completed Tab June 21, 2002. The completed alignment tab in place on the fuselage. You can see the pin in place with the bushing. I need to find out if the bushing should be trimmed or not. You can also see that the tab sticks out a bit past the side of the fuselage. I will need to trim the tab to make it flush.