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NOTE: Each of the pictures on this page is a clickable thumbnail which will open up to a much larger image for detailed viewing. In some cases you will notice differences between the photos and your plans and parts. This is due to changes made during the building of the prototype. I've tried to make note of the changes but if I missed anything please assume that the plans are correct.

Horizontal Stabilizer & Elevators

Image 1

Image 1

1. Begin construction by assembling the center rib sandwich which consists of S1 with an S1a laminated to each side.

2. Dry fit ribs S1 through S7 to spars S8 and S9. Square up the assembly over the plan and tack glue, pin, or weight in place.

3. Once satisfied that the assembly is square glue with thin CA.

4. Carefully sand the leading edge of each rib to match the angle of S10. Sand the root end of each S10 to get a tight joint where they join in the middle. Attach the two S10 sub leading edge pieces to the assembly.

5. Block sand the top of the entire structure to prepare it for sheeting. It should look like Image 1 at this point.

Image 2

Image 2


6. Sheet the top of the horizontal stab in two halves with 1/16" balsa. (Image 2) Make the skins about 1/8" oversize all the way around. I use wood glue (Aliphatic) for attaching the sheeting and weight with zip-lock bags full of sand while the glue dries. See the Tips & Tricks page for some advice on gluing up skins for sheeting. To save time later go ahead and make up the bottom skins as well.

Image 3

Image 3

7. Remove the stab from the building board and carefully cut or break free the jig tabs. Block sand the structure in preparation for sheeting the bottom.

8. Locate two each of SS2, SS4, and SS7 and make up the stab saddle per Image 3.

9. Place the horizontal stab in the saddle per Image 4 and add the bottom sheeting. Be certain to weight the stab firmly in the saddles while the glue dries in order to maintain a warp free structure. Once dry sand the sheeting to final size.

Image 4

Image 4


NOTE: The steel block shown in Image 4 is a "1-2-3 Block", thus called because it is exactly 1" x 2" x 3". They are solid steel, quite heavy as you can imagine, and are very handy. I use them extensively (as you will see) and recommend them as an almost "must have" building tool. They also come drilled and tapped so that they can be bolted together to form larger and more complex shapes for jigging. Enco is one of many sources for 1-2-3 Blocks.

Image 5

Image 5

10. Make up the two leading edge pieces from soft 1/4" balsa. Leave these a tad large for now and sand to fit after attaching. Temporarily install the 1/8" leading edge dowel so you can fit the leading edges around it per Image 5. It is recommended that wood glue be used for attaching the leading edges so that there are no problems later when sanding to shape. If you use CA apply it sparingly and only down the center of leading edge so that it does not squeeze out. CA gets much harder than balsa and trying to sand and blend the two materials together is an exercise in futility.

Image 6

Image 6


11. Mark two lines parallel to the trailing edge of the stab sheeting from tip to tip, one at 2 1/8" and one at 2 1/2". Those two dimensions are not critical, so long as the lines fall anywhere between spars S8 and S9. Carefully cut and remove the sheeting between these two lines. (Image 6)

12. Use a razor saw to carefully cut through each rib to seperate the elevators from the horizontal stab. Sand back flush to spars S8 and S9 respectively. (Image 7)

Image 7

Image 7


13. Add trailing edge S11 and the two S14 tip blocks to the horizontal stab and rough sand to shape. (Image 8)

Image 8

Image 8


14. Make up the root end elevator blocks from the S13 core with an S13a laminated to either side. You will need two such assemblies.



Image 9

Image 9

15. Add the S12 leading edge, S13/S13a root block, S15 tip block, and the 3/16" x 3/4" balsa trailing edge to each elevator. (Image 9) Please note that the design is slightly changed from that of the prototype and your trailing edge should extend the entire length of the elevator. Be sure the hole in the root end of S12 lines up with the pocket in the S13/S13a assembly so that the elevator joiner wire can be inserted later. Block sand to shape but do not round the tip or bevel the leading edge at this time.

16. Tack glue or tape the elevators and horizontal stab together and do the final shaping of the tips as one unit. In order to get the elevators positioned accurately it is advised that the joiner wire be temporarily installed while shaping the tips. Note that you will need to recess the trailing edge of the stab as well as the leading edge of both elevators for the wire joiner per the section "B" detail on sheet 1 of the plans.

17. Remove the elevators from the stabilizer and final shape the leading edge, again per the section "B" detail on the plans.

18. Slot the stabilizer and elevators for your favorite CA type hinge but do not permanently install them at this time.



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