Next, tie turnbuckles(W042) where indicated to the compression bars and to the holes in ribs #6 and #15. You will use 14 turn- buckles for each half of the upper wing. Begin each run of the rig- ging line by tying one end to a turnbuckle and permanently affix- ing it with a drop of super glue. Run the line through the holes as indicated, ending through the second turnbuckle. Affix a small weight on the line to keep it taut (Fig. 2/13-D) and seize thread around the line at that point. Apply a drop of super glue there and at each place the line passes through a rib. Cut off the excess line and repeat the procedure until all of these alignment lines are in place. Note that the lines connect directly to rib #1, without a turnbuckle.

Joining the wing halves:

This step requires patience in order to get the correct 1.5 degrees dihedral when joining the upper wing halves and a little

extra care to avoid making your fingers part of the assembly. Begin by taping a 5mm high riser block, cut from spare wood strips, to rib #12 on each wing half. [Note that this varies slight- ly from Fig. 2/15.] Next, insert the two joint pins (WP5101-24) through ribs #1. There should be just enough play so that, with the top of ribs #1 touching, the center of the assembled wing can sag to the table top. Super glue the topside contact edges togeth- er.

When the glue is hard, carefully turn the assembly over and run a drop of super glue into the gap to lock the joint pins in place and to strengthen the joint. Finally, shape a shim to fit the gap(Fig.2/14), without prying it apart, and glue this in place with white or yellow glue. After everything is dry, finish off the wing by sanding the joint as needed and affixing the four joint plates(Ni28-020).

Stage 3: Building the Lower Wing and Ailerons

The lower wing will also be constructed in right and left halves, but there will be no dihedral when they are attached to the fuse- lage. The ailerons are built integral to the wing structure and will then be cut free to operate. This ensures that it all lines up per- fectly. Refer to Figures 3/1 through 3/10 for the number and loca- tion of the parts. As before, ribs are numbered out from the cen- terline. The following procedures will need to be repeated for the right and left lower wings.

PARTS LIST FOR STAGE 3:

WP3688-24

Rib caps

.02 x 5/64 wood strips

Ni28-021

Ribs #1

4

laser-cut wood parts 3/64 thick

Ni28-022

Ribs #2

2

laser-cut wood parts 3/64 thick

Ni28-023

Ribs #3, 5

4

laser-cut wood parts 3/64 thick

Ni28-024

Ribs #4, 6

4

laser-cut wood parts 3/64 thick

Ni28-025 Ribs #7, 8, 10, 11 8

laser-cut wood parts 3/64 thick

Ni28-026

Ribs #9

2

laser-cut wood parts 3/64 thick

Ni28-027

Ribs #12

2

laser-cut wood parts 3/64 thick

Ni28-028

Ribs #13

2

laser-cut wood parts 3/64 thick

Ni28-029

Ribs #14 -

 

 

 

 

ailerons only

2

laser-cut wood parts 3/64 thick

WP3626-24

Front and rear spars

2 3/32 x 1/8 wood strips

WP3202-40 Wing tips

 

 

 

 

(laminated)

5 .02 x 5/32 Tanganyika wood strips

WP3202-40

Center trailing

 

 

 

 

edges (lam.)

5 .02 x 5/32 Tanganyika wood strips

WP3640-24

Leading edge

2

3/16 x 3/16 wood strips

WP3620-24

Trailing edge

2

1/16 x 1/8 wood strips

WP3688-24

Leading edge cover

5 .02 x 5/64 wood strips

WP40264

Aileron torque bars

2 5/64 x 9 1/4 brass rod

Ni28-033

Aileron hinges

6

Britannia castings

Ni28-034

Lower wing joint

1

Britannia casting

Ni28-018

Compression bars

2

Britannia casting

W042

Turnbuckles

16

Britannia castings

WP1205

Rigging cable

7’ Metal-gray thread

J004 R-L

Lower wing tip

 

 

 

 

jigs

1

laser-cut wood part 5/32 thick

J005 R-L

Lower center

 

 

 

 

trailing edge jigs1

laser-cut wood part 5/32 thick

Wing ribs; cap strips:

Prepare the lower wing ribs(Ni28-021-029) and cap strips(WP3688-24) exactly the way you did for the upper wing. Begin by laminating two parts Ni28-021 to form each rib #1. Take the required lengths of the cap strips from full-size Plan D02.

Wing tips and center trailing edges:

The technique is the same as for the likewise laminated parts for the upper wing, using five Tanganyika wood strips(WP3202-40). In this case, use jigs J004 and J005 and refer to Plan D02. As before, shape the laminated parts as necessary for installation on the wings.

Inserting the spars; leading and trailing edges; aileron torque bars; aileron hinges:

Referring to full-size Plan D02, cut the front and rear spars (WP3626-24) to length and shape them as required. Adjust the spar holes in the ribs so the spar slips through without binding, then cut and insert the aileron torque bar(WP40264), adding rib #14 between ribs #6 and 7, and the hinges(Ni28-033) between ribs #7 and 8, #9 and 10, and #12 and 13. These should turn freely on the torque bar. The leading edge, spars and torque bar will pro- trude through rib #1. Pin the assembly down, making sure every- thing is square, then glue the spars in place.

The torque bar should be glued only to ribs #7-14 and be able to turn without binding in the other ribs. Do not glue the hinges to the rear spar. This will be done after the aileron is cut free from the wing and sanded to its final shape.

Finally, cut the leading (WP3640-24)and trailing(WP3620-24) edges to size and glue them in place against the ribs, then add the laminated wing tips and center trailing edge as for the upper wing. After the glue dries thoroughly, unpin the structure. Using a long strip of sandpaper (about 11”) affixed to the same length straight

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Model Shipways 28 manual Stage 3 Building the Lower Wing and Ailerons