ANNIVERSARY CUB RC82 WING CONSTRUCTION

As mentioned in the introduction, you can build either a standard PIPER J-3 CUB (84-1/2" wingspan) or a CLIPPED WING CUB (68-1/4" wingspan) from this kit. All of the parts to build either version are included. The differences between the J-3 and the CLIPPED WING are the wing panel length, the wing strut length, and the jury strut patterns. These differences are clearly shown on the full-size plans. Just make sure you are using the correct plans for the airplane you decide to build.

To build a PIPER J-3 CUB wing:
  • The basic Wing Plan is on plan sheet 2
  • The Wing Struts are on plan sheet 3
  • The Jury Struts are on plan sheet 3
To build a CLIPPED WING CUB wing:
  • The basic Wing Plan is on plan sheet 4
  • The Wing Struts are on plan sheet 4
  • The Jury Struts are on plan sheet 3

If you are using the correct plan, the only differences will be in the length of some of the parts. These parts will be cut from the same stock for either version. The differences in length will be noted in the instruction steps. However, note that ALL the photos are of the J3 wing.

72.

Locate the two plywood W-1 wing ribs (sheet 1). When you punch out the circles in the W-1 ribs, donít throw the circles away! Cut two 7-3/8" long pieces of the .880" id Phenolic Tube Wing Joiner Sleeve material. Carefully glue one of the plywood circles, that you removed from the W-1 ribs, onto one end of each of the phenolic tubes. Lightly sand the outer edges of the plywood circle flush with the tube. Set the tubes aside until needed later.
NOTE: If you are building the Clipped Wing Cub, the phenolic tubes should be cut 5-3/4" long.



73a.

Locate the two plywood W-1A ribs, (sheet 15). Glue one W-1A to each of the W-1 ribs. Be sure to make a left and a right rib assembly by gluing the W-1A ribs on opposite sides of the W-1 ribs! Match up the cutouts in the ribs carefully when gluing them in place (the photo shows the phenolic tube being used to help align the holes).

b.

Install an 8-32 Blind Nut in the small hole in each of the W-1A ribs.

74a.

Tape or pin the one of the wing panel plans down on a flat building board. Cover with wax paper or plastic wrap.

b.

Cut to length and pin down on the plan the 1/4" sq. balsa Main Spar, the 3/16" sq. balsa Rear Spar, and the 1/8"x1/4" balsa Wing Spar. Itís best to leave the spars a little long on the inboard end of the wing - they can be sanded flush with the end rib later.

75a.

Locate the Front Spar Web and Rear Spar Web (sheet 6), and ribs W-2 (sheet 3), W-3 (sheet 1), W-4 (sheet 4), and W-5 (sheet 5). Insert the W-2, W-3, W-4, and W-5 ribs into their slots in the spar web. Set this assembly in place on the spars.
NOTE: If you are building the Clipped Wing Cub, the correct Front Spar Web and the Rear Spar Web are on sheet 25. The wing ribs are all the same, but there are 2 less W-4 ribs in a Clipped Wing Cub wing panel.

b.





c.

Slip the W-1 rib assembly that you made in step 73 in place at the root end of the wing panel. Remember, the side with the W-1A and the blind nut must be on the inside of the wing.

Now carefully pin all the spar webs and ribs to the spars, starting with the W-1 rib. Make sure W-1 lines up right on the lines on the plan and pin it in place. Then, pin the spar web next to W-1 down to the spar, making sure it is up tight against W-1.

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Proceed down the length of the wing panel, pinning the parts to the spars. You may notice as you are going along that some of the ribs may not line up exactly with the plan. This is because the plan paper can shrink or expand a little bit in size with climate changes. Donít worry about it. As long as W-1 is in the correct position, and the rest of the ribs are fitted into their proper slots in the spar webs (which donít ever change), the wing panel will turn out OK. When you get to the last rib, it shouldnít be off more than an 1/8" or so.

d.

Begin gluing all the joints of the wing assembly together with Thin CA. Hold a 90 deg. triangle up against the ribs while gluing them to insure that they are 90 deg. to the building board.

76a.

Carefully slide the phenolic tube Wing Joiner Sleeve (from step 72) into the appropriate holes in ribs W-1, W-2, and W-3. Glue the tube to the ribs.

b.

Cut to length and glue in place the three top spars: 1/4" sq. balsa Main Spar, 3/16" sq. balsa Rear Spar, and 1/8"x1/4" balsa Wing Spar.

77.

Locate the pre-shaped balsa Leading Edge. Notice that it is not symmetrical! Hold the Leading Edge against one of the wing cross-section drawings on the plan, and after you are sure that you have it matched up correctly, mark an "up" arrow on one end. Then, cut it to length and glue it in place in the front notches of the ribs. Make sure you glue it into the wing right side up!

78.

Cut a piece of 3/32"x1"x13-3/4" balsa T.E. Sheet from the 36" stock provided. Glue it in place on the ends of the W-1, W-2, W-3, and W-4 ribs. Make sure the back edge of the T.E. Sheet is right on the line on the plan.
NOTE: If you are building the Clipped Wing Cub, cut the piece to 5-7/8" long and glue it to the W-1, W-2 and W-3 ribs - there is no W-4 rib at this location.




79.

Cut a piece of 3/32"x3/4"x21-1/4" balsa from the 24" stock provided. This is for sheeting the rear edge of the aileron bay. Glue it in place to the ribs and to the 1/8"x1/4" wing spar. Look closely at the drawing - note that the inboard end of this sheeting should extend past the wing rib at the inboard end of the aileron about 3/16", so that it will line up with the cap strips to be put on that rib later.




80a.

Use a long straightedge to true up one edge of a 3/32"x3"x36" balsa sheet for the wing leading edge sheeting. This edge will go against the rear face of the shaped leading edge that is already glued on the front of the wing. Trial fit the leading edge sheet to the wing to figure out where to trim the back edge. You want the back edge of the sheeting to end up sitting halfway across the 1/4" top main spar, leaving the rear of the spar exposed 1/8" for the cap strips and center sheeting.

b.

Once youíve got the leading edge sheet trimmed to fit, glue it in place. Weíve found the easiest way to accomplish this is to do it in two steps.
1) Start by gluing the front edge of the sheet to the top rear face of the shaped leading edge. Apply a bead of glue along the entire length of the sheet, on its front edge only. Set the sheet in place againt the shaped leading edge, holding it up at about a 45 deg. angle. Spray this joint with CA accelerator.

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2) When dry, apply glue along the ribs and the front half of the top spar. Uniformly press the sheet down onto the ribs and spar. Use a straightedge and weight to hold the sheet flat to the spar and spray with accelerator.

Builderís Tip: You may need to wet the outside surface of the sheet slightly to make it bend over the ribs easier.

81.

Locate the 3/32"x3" balsa sheet left over from sheeting the nose of the fuselage. This will be used for sheeting the top of wing between ribs W-1 and W-2, from the main spar all the way back to the trailing edge. Cut lengths of the balsa sheet to fit over the W-1 and W-2 ribs, and glue in place.
Note: Be sure to remove all the pins from the ribs and spars between the W-1 and W-2 ribs.

82a.

Cut to length and glue in place the 3/32"x1/4" balsa Cap Strips over ribs W-3, W-4, and W-5. Carefully study the plans so you will know which Cap Strips should be put on centered over the rib and which ones should be put on along the edge of a rib.

b.

The trailing edge of the tip rib should be capped with a short piece of the 3/32" sq. balsa left over from the fuselage bottom corner stringers.




83.

When everything is dry, remove the wing panel from the building board. Thoroughly inspect your work and re-glue all joints with a small bead of Medium CA .

84a.

Locate the plywood Front Strut Mounts, Rear Strut Mounts, and Jury Strut Mounts (sheet 15). Lay them in place on the wing plan, carefully centering the holes in the mounts with the blind nuts on the plan. Now lay the wing panel back in place on the plan, on top of the strut mounts. Carefully line the wing up with the plan. One at a time, glue the strut mounts to the wing structure, making certain you get them in the proper location.

b.

Locate the Strut Mount Doublers (sheet 15). Determine which doubler fits behind which strut mount, and then glue them in place inside the wing. When dry, use a 9/64" drill to re-open the holes for the blind nuts.

c.

Install 4-40 Blind Nuts in the holes from the inside, gluing them to the strut mount doublers.

85a.

Pin the wing panel on the building board upside down along the main spar. Using scrap wood to support the leading and trailing edges of the wing. It is important to properly support the wing panel during the next step in order to avoid inducing a warp into the structure.


b.


Locate the Bottom L.E. Sheeting (sheet12). Check the fit of the Bottom L.E. Sheeting to the wing structure, especially around the strut mounts. Bevel the front edge of the Bottom L.E. Sheeting slightly with a sanding block to achieve a good joint with the back of the formed balsa leading edge. When everything fits properly, glue the Bottom L.E. Sheeting in place in the same manner you did the top leading edge sheeting in step 80b.
NOTE: If you are building the Clipped Wing Cub the Bottom L.E. Sheeting is in laser-cut sheet 24.


86.

Cut to length and glue on the bottom 3/32"x1"x13-3/4" balsa T.E. sheet (remember step 78).
NOTE: Itís 5-7/8" long if youíre building the Clipped Wing Cub.

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87. Cut to length and glue on the bottom 3/32"x3/4"x21-1/4" balsa sheet for the rear edge of the aileron bay (remember step 79). When dry, use a sanding block sand the top and bottom sheets even with the 1/8"x1/4" wing spars.

88.

Trim to length the 1/8"x1"x24" balsa sheet that caps off the aileron bay. Glue it in place, using tape or pins to hold it until dry. When dry, carve and sand off the overhanging excess 1/8" sheet flush with the rest of the wing.
89. Cut lengths of 3/32"x3" balsa to sheet over the bottom of ribs W-1 to W-2, from the main spar all the way back to the trailing edge (remember step 81).

90.

Cut to length and glue in place all the 3/32"x1/4" balsa Cap Strips for the bottom of the wing (remember step 82a). Note, that here on the bottom of the wing, the two Cap Strips on each side of the aileron servo bay should not be centered over the ribs, as they were on top of the wing. These two cap strips should be glued along the edge of the ribs so they are completely outside the servo bay.

91.

The trailing edge of the tip rib should be capped on the bottom with a short piece of the 3/32" sq. balsa (remember step 82b).

92.

Glue the 3/32" balsa Triangle (sheet 25) in at the inboard end of the aileron bay.




93.

When dry, unpin the wing panel from the building board. Use a large sanding block with 80 grit paper to carefully smooth the entire wing panel. The goal is to only level out any mismatched areas, not to do the final sanding. Sand off any overhanging balsa sheeting or spars flush with the root rib and the tip rib.

Wing Tip


94.

Locate parts TR-1 and TR-2 (sheet 11). These are small subribs that go on the outside of the last W-4 rib at the tip end of the wing panel to help support the wing tip sheet. Refer to crosssection W-4 one the plane to familiarize yourself with their precise location. Then, glue them in place on the tip rib.

95.

Locate the plywood Wingtips (sheet 27) and balsa parts TS-1, TS-2, and TS-3 (sheet 11). Glue the balsa parts in place on the top and bottom of the plywood Wingtip.

96.

Locate parts TB-1 (sheet 11), and TB-2 (sheet 5), and glue them in place on the tip end of the wing panel. TB-1 goes against the ends of the 1/4" sq. balsa Main Spars, and TB-2 goes against the ends of the 3/16" sq. balsa Rear Spars, as shown on the plans. Make sure these parts are 90O to the rib.



97.

Locate plywood rib W-6 (sheet 11) and set it in the notches in TB-1 and TB-2. Then, pin the Wingtip assembly (from step 24) in place to the ends of TB-1 and TB-2, to rib W-6, and to the leading and trailing edges of the wing panel. At the leading edge, make sure the Wingtip lines up with the back edge of the shaped balsa leading edge piece. At the trailing edge, use a 90 deg. triangle to make sure that the tail end of the end rib doesnít get pushed out of shape while you are gluing on the wingtip. Once you have all the pieces in correct alignment, glue them together.

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98. Locate the 1/2"x1"x2" balsa Wing Tip Block and glue into place at the front of the wingtip.




99.

Sheet the front of the wingtip, top, and bottom with 3/32"x3" balsa sheet.

100.

Glue 3/32"x1/4" balsa capstrips to the top and bottom of rib W-6.

101.

Carve and sand the tip block and the tip sheeting to flow into the wing leading edge and the wingtip.

102.

Tape a piece of plain paper over one end of your sanding block to protect the capstrip while you sand a bevel in the edge of the balsa TS-1, TS-2, and TS-3. Do this to the top and bottom of the wingtip.




103.

Finish the wingtip by sanding the trailing edge of the wing panel end rib to blend in flush with the wing tip. Also, round off the outside edges of the wingtip plate.

Ailerons



104a.

Cut two 3-3/8" long pieces of 1/4"x1/2"x16" grooved basswood Hatch Rail material to fit between the two W-5 wing ribs. Glue one of the pieces right in front of the 3/16" sq. rear spar for the rear Hatch Rail. Study the plan drawings carefully to understand the orientation of the Hatch Rails. Note that the top edge of the Hatch Rail should be flush with the cap strips on the bottom of the wing.

b.

Lay the plywood Aileron Hatch (sheet 7) in place on the lip of the rear Hatch Rail. Now, place the front Hatch Rail on the lip so you can determine the exact location for the front Hatch Rail. Glue the front Hatch Rail in place to the ribs.

c.

Lay the plywood Aileron Hatch on the plan to make sure you understand where the slot for the servo arm should end up. Then, lay the Aileron Hatch in the same position in the wing (if you install it wrong, the pushrod will not line up with the aileron horn). Drill pilot holes in the Hatch Rails with a 1/16" drill bit, using the holes in the Hatch as a guide. Screw the Hatch in place with #2 x3/8" Sheet Metal Screws.

105a.

Pin the Aileron Bottom Sheet (sheet 9) flat onto the building board.

b.

Cut a piece of 1/8"x1/4" balsa stick for the bottom Aileron Spar and glue it in place at the leading edge of the Aileron Bottom Sheet.

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c. Glue seven balsa Aileron Ribs (sheet 11) in place, locating them in the slots in the Aileron Bottom Sheet.


d.

Locate the plywood Aileron Horn Mount (sheet 27). Notice the small hole in the part. This is where the nylon control horn will be screwed on later. In order to make that installation of the control horn easier later on, itís a good idea to pre-thread the hole now by screwing in a #2 x3/8" Sheet Metal Screw and then taking it back out. Do this a couple times and then, after the screw is out, soak a little Thin CA glue in the threads to toughen them up. When done, glue the plywood Aileron Horn Mount in place on the Aileron Bottom Sheet - locate it 5-1/8" from the inboard end of the aileron (see plan).

106a.

Cut a piece of 1/8"x1/4" balsa stick for the top Aileron Spar and glue it in place in the notches of the ribs.

b.

Use a small sanding block to taper the back edge of the Aileron Bottom Sheet to match the angle of the ribs.

107a.

Trial fit the Aileron Top Sheet (sheet 8). Adjust if necessary, then glue it in place.

b.

Remove the aileron from the building board and block sand the top and bottom sheets smooth. Also, sand the two 1/8"x1/4" Aileron Spars flush with the front face of the ribs.

c.

Finish off the front of the aileron by gluing on a piece of 1/8"x1" balsa. When dry, carve and sand off the overhang flush with top and bottom aileron sheet.

108a.

With a razor saw, cut off the base of a small Nylon Control Horn (4 holes). Inlet the bottom of the aileron sheeting to allow the Nylon Control Horn to be slid in place alongside the plywood Aileron Horn Mount. Before cutting, study the wing plan and the cross-section drawings to familiarize yourself with how the Nylon Control Horn should be installed in the aileron. Notice that the horn should be installed on the outboard side of the plywood Aileron Horn Mount (installed in step 205d). Also, determine how far into the aileron the horn should be located.

b.

Hold the Control Horn in position against the plywood mount and mark the location of the pre-threaded hole onto the horn. Remove the Control Horn and drill the hole with a 3/32" bit. Then, apply a small amount of epoxy to the horn and screw it securely in place against the plywood mount.

c.

Fill in behind the horn, on the bottom of the aileron, with 3/64"x3/8" scrap balsa to provide a place to attach the covering material later.



d.

Smear a little more epoxy glue over the screw and horn assembly inside the aileron to make sure it never comes loose.

Aileron Servo Installation

109.

Lay your aileron servo on its side with a 1/32" thick scrap shim of plywood or cardboard underneath it. Then, place the 1/4"x3/4"x7/8" basswood Aileron Servo Mounts under the servo lugs and mark the location of the servo mounting holes onto the mounts. Drill 1/16" dia. pilot holes for the mounting screws.

110.

Mount the servo to the mounts using the grommets, eyelets, and screws that came with the servo.

111.

Position the mounted servo on the plywood Aileron Hatch, centering the servo arm in the slot. Glue the servo mounts to the hatch cover. Make sure you glue it to the correct side of the slot so the pushrod will line up with the aileron horn. The plan shows the proper arrangement.

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112.

Mount the aileron servo/hatch assembly in the wing. Use a 12" aileron extension cable (not supplied) to extend the servo wire to the end of the wing panel.


CONGRATULATONS!
You have now completed one wing panel and one aileron.
Repeat the steps to build the opposite wing panel and aileron.

Mounting The Wings

113a.

Locate the 7/8" od x17-1/2" aluminum tube for the Wing Joiners. Cut two 8-3/8" long pieces.

b.

Slide the aluminum tube Wing Joiners inside the phenolic tube sleeves that are built into the root ends of both wing panels. Push them all the way in, until they bottom out against the plywood end caps of the phenolic sleeves. That should leave about 1-3/16" of aluminum tube sticking out of the end of the wing panel.

114.

Locate the 3/16" dia. x6" hardwood Rear Wing Dowel. This dowel goes completely thru the cabin center section and sticks out on both sides. Itís purpose is to engage the aft portion of the wing panels, to prevent them from pivoting around the aluminum tube Wing Joiner at the front. Slide the dowel thru the small holes at the rear of the cabin center section, until there is an equal amount of dowel sticking out each side of the fuselage.

Note: You can glue the dowel in the center section at this time if you wish, or as we prefer, you can wait until after the fuselage is covered to glue the dowel in permanently.


115.

Mount the wing panels on the fuselage by sliding the protruding part of the aluminum Wing Joiner into the sleeve in the center section, while at the same time sliding the protruding Rear Wing Dowel into the wing panel.

116.

Use an 8-32 x1/2" Socket-Head Bolt along with a #8 Flat Metal Washer, from the inside of the cabin, to hold the wing panel up tight against the fuselage. Remember, 8-32 Blind Nuts were mounted inside the W-1 rib for this purpose way back at the beginning of the wing panel construction.

Wing Struts

The Front Wing Struts for the Piper J-3 Cub are 1/4"x1/2"x24-1/4" spruce, and the Rear Wing Struts are 1/4"x3/8"x24-1/4" spruce. Study the J-3 Wing Strut Plan (plan sheet 3) to understand the design of the wing struts. Notice that the Front and Rear Struts will be joined permanently together into a one-piece "V"-shaped wing strut assembly.

NOTE: If you are building the Clipped Wing Cub, the Front and Rear Struts are both made of 1/4"x1/2"x24-1/4" spruce. The Clipped Wing Strut Plan is on plan sheet 4.

117a.

Lay the spruce Front Wing Strut down on the plan. Mark and cut the ends of the spruce to match the plan, being careful to get the overall length exact.


b.

Lay the spruce Rear Wing Strut down on the plan. Cut the lower (fuselage) end of this strut as shown on the plan. It must be cut at an angle to mate up properly with the Front Wing Strut. After youíve got that end done, mark and cut the other end of the Rear Wing Strut to proper length.

c.

Mark the slots to be cut in each end of the spruce struts. Cut the slots down the middle of the sticks with a band saw or small hand saw.

118a.

Locate two .060"x3/8"x2-1/4" pieces of aluminum for the Fuselage Strut Fittings. Lay them on the Fuselage Strut Fittings drawing (plan sheet 3) and mark the locations for the 1/8" and 3/32" dia. holes. Clamp the part in a vise and drill the holes (use a drill press if available).

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b. Round the two outside corners of the fittings with a file or grinder.

c.

Lay the Fuselage Strut Fitting back over the plan pattern and mark the bend line exactly where shown. Clamp the part in a vise right at the line, and gently bend it to the angle shown.

119.

Hold the Fuselage Strut Fittings in place on the bottom of the fuselage and mark the location of the two mounting holes. Drill the holes with a 1/8" dia. bit. Mount the Fuselage Strut Fittings to the fuselage with two 2-56 x 3/8" Bolts and 2-56 Blind Nuts. Glue the Blind Nuts on the inside of the fuselage.

120.

Inside the fuselage, add a 1/2" balsa triangle to the front edge of the rear landing gear block, between the blind nuts.




121a.

Locate four .060"x3/8"x2-1/4" pieces of aluminum for the Upper Strut Fittings. Lay them on the Upper Strut Fittings drawing (plan sheet 3) and mark the locations for the 1/8" and 3/32" dia. holes. Clamp the part in a vise and drill the holes.




b.

Round the two outside corners of the fittings with a file or grinder.

c.

Bend the Upper Strut Fittings as shown on the plan, making two #1 and two #2 fittings. The difference between the #1 and #2 Upper Strut Fittings is only in the slant of their bend lines. Make sure you produce two of each type. Mark the bend line exactly where shown, then clamp the part in a vise right at the line and gently bend it to about a 20 degree angle.

122a.

Locate two .060"x15/16" (tapered) x2-3/16" aluminum Lower Strut Fittings. Lay them on the Lower Strut Fittings drawing (plan sht.3) and mark the locations for the 1/8" and 3/32" dia. holes. Clamp the part in a vise and drill the holes.

b.

Round the two outside corners of the fittings with a file or grinder.

123.

Epoxy the spruce Front and Rear Wing Struts onto the aluminum Lower Strut Fittings. Double check them against the plan to make sure the "V" angle is correct. Let dry.

124.

Next, we need to trial fit the wing strut assemblies on the airplane, in preparation for gluing the Upper Strut Fittings into the struts.
RIGHT WING
Use a #1 Upper Strut Fitting for the Front Strut
Use a #2 Upper Strut Fitting for the Rear Strut
LEFT WING
Use a #2 Upper Strut Fitting for the Front Strut
Use a #1 Upper Strut Fitting for the Rear Strut

a.

Bolt the wing panels in place on the fuselage.

b.

Fasten the wing strut assemblies in position, one on each side of the fuselage, bolting the Lower Strut Fittings to the Fuse Strut Fittings with 4-40 x3/8" Socket-Head Bolts and Hex Nuts.

c.

Bolt the Upper Strut Fittings to the plywood strut mounts built into the wing with 4-40 x3/8" Rd.Hd. Bolts.

d.

Check the fit of the Upper Strut Fittings into the slots in the top ends of the wing struts. If they donít line up properly, double check to see that youíve got the correct upper fitting in the correct strut. If itís not that, you may have to adjust the bend angles of the upper strut fittings and/or the fuselage fitting slightly to get a good fit.

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e. When satisfied with the fit, take the Upper Strut Fittings off one at a time, apply epoxy, slip the fitting back into the slot, bolt it back in place, wipe off any excess glue, and then let dry.

125.

When dry, remove the strut assemblies from the airplane. Carve and sand the spruce Wing Struts to finished shape.

126.

Reinforce the ends of the spruce struts with a layer of fiberglass cloth and thin CA glue. Also, cover the areas near the center of each strut where the jury struts will go with fiberglass cloth. When dry, sand smooth.


127.

Lay the wing strut assembly on the plan and mark the location for the 2-56 x3/8" Flat-Head Bolts that hold the bottoms of the brass Jury Struts. Drill a 3/32" dia. hole through the spruce struts at these locations. Countersink the holes on the bottom of the struts so that the heads of the bolts will be flush with the spruce. Then, thread the bolts in place and leave them there.

128a.

Re-attach the wing strut assemblies to the airplane.

b.

Cut two 3-3/8" long pieces of 5/32" od brass tubing for the Jury Strut Spreader.
Note: If you are building the Clipped Wing Cub, the Jury Strut Spreader should be 2-7/8" long.

c.

Flatten both ends of the Jury Strut Spreader as needed to clear the spruce struts (approximately 3/8" on each end as shown on the plan).
Builderís Tip: A regular hand pliers works best for flattening and bending the ends of these brass tubes.

d.

Hold the Jury Strut Spreader in place on the wing struts and mark locations of the holes near each end. Drill the holes with a 3/32" dia. bit.

129a.

Cut two 4-3/4" long pieces of 5/32" od brass tubing for the Front Jury Struts.
Note: If you are building the Clipped Wing Cub, the Front Jury Struts should be 5-5/16" long.

b.

Flatten the ends of the Front Jury Struts and mark the location of the holes. Drill the bottom hole with a 3/32" dia. bit. Drill the top hole with a 1/8" dia. bit. There are patterns on the plan to use as a guide for bending the Front Jury Struts to shape. Be sure to make a right and a left!

130a.

Cut two 4-7/8" long pieces of 5/32" od brass tubing for the Rear Jury Struts.
Note: If you are building the Clipped Wing Cub, the Rear Jury Struts should be 5-1/4" long.

b.

Flatten the ends of the Rear Jury Struts and mark the location of the holes. Drill the bottom hole with a 3/32" dia. bit. Drill the top hole with a 1/8" dia. bit. There are patterns on the plan to use as a guide for bending the Rear Jury Struts to shape. Be sure to make a right and a left!


131.

Bolt the all the Jury Strut tubes in place on the Wing Struts. Epoxy together the lower ends of the Jury Struts and the Spreader where they overlap each other and the spruce wing struts. Use 2-56 Hex Huts to fasten them to the 2-56 Bolts that are already in the Wing Struts. Use 4-40 x3/8" Rd.Hd. Bolts to fasten the top ends of the Jury Struts to the wings.

Main Landing Gear

132.

Locate the formed wires 5/32" Main Landing Gear, 5/32" L.G. Rear Brace, 1/8" Top Shock Strut, and 1/8" Bottom Shock Strut. Sand all the wires with 220-grit paper, then wipe clean with acetone or paint thinner.

133a.

Place the Main Landing Gear wire in the front grooved landing gear block in the bottom of the fuselage. Place the L.G. Rear Brace wire in the aft grooved landing gear block. The Main Landing Gear should be perpendicular to the bottom of the fuselage, while the L.G. Rear Brace should be angled forward to meet it near the axle. You will have to trim the groove in the rear block slightly to allow the Rear Brace wire to swing forward.

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b. The wires are held in the grooved blocks with the four Nylon Landing Gear Straps provided. The straps should be installed all the way to the ends of the grooved blocks, right up against the wire where it exits the block. This is done to insure the landing gear cannot shift sideways in a rough landing. Mark the location of the holes on the grooved blocks. Then, use a 3/64" bit to drill a pilot hole for the # 2 x3/8" Sheet Metal Screws.

134a.

Bind the ends of the Main Landing Gear, the L.G. Rear Brace, and the 1/8" Bottom Shock Strut together near the axle with the soft copper wire supplied. Itís easiest to first tack glue them together with Medium CA to hold them in alignment while you wrap them. If the wires donít line up exactly right with each other, rebend as necessary to get them to fit properly. Make the copper wire wrapping as tight as you can, with each strand of copper wire right next to the previous one. There should be no gaps between the strands of copper wire. Donít worry about running out of copper wire, as we have included extra to help insure that you can make these bindings very strong.

b.

Next bind the 1/8" dia.Top Shock Strut wire in place at the top of the Main Landing Gear wire. Position this wire carefully (see front view plan). The middle bend of this Top Shock Strut should contact the middle bend of the Bottom Shock Strut. For flying, the Top and Bottom Shock Struts will be bound together at this spot by rubber bands, which will serve as an effective shock absorber.

c.

When you have all the wires bound together in proper alignment, solder the bindings securely with normal rosin core solder. Be sure to use a soldering iron or torch with enough heat output to get the wires and bindings hot enough for the solder to flow smoothly. Also, use plenty of solder paste to help the solder flow completely around and thru the bindings. Protect the fuselage during the soldering operation with a cloth so that dripping solder or paste will not fall on the wood. After both axles are soldered and cooled off, carefully remove the wires from the grooved blocks.


135.

After all the solder joints are cool, file and sand them to smooth out any prominent bulges in the bindings. Clean all the wires and joints with dope thinner or other suitable solvent.

136a.

A sheet of 3/16"x6"x8" balsa is provided for fairing in the sides of the Main Gear. Cut out a right and left fairing to fit between the gear wires. Note proper grain on the plan. Epoxy the balsa fairings in place and allow to dry.

b.

Using a sanding block, sand the balsa fairings flush with the wires if they are sticking out. Also, sand the top edge of the fairings round.



b.

Fill in any voids in the landing gear fairings with extra epoxy glue or epoxy putty.

137.

Solder a #6 Flat Metal Washer on each of the axle wires, right up against the bend in the wire, to keep the wheels from binding on the bend.

Attaching The Tail Surfaces

138a.

With the wings and struts mounted to the fuselage, place the stabilizer in position. Secure it lightly in place with a couple pins.

b.

CHECK TOP VIEW ALIGNMENT: Use a measuring tape to check the distance from one stab trailing edge tip straight ahead to the wing trailing edge. Now make the same measurement on the other side of the model. The two measurements should be the same! If not, adjust the stab accordingly. Once the alignment is correct, put in some more pins to keep it from moving. Use a pencil to mark the location of the fuselage sides on the bottom of the stab.

c.

CHECK FRONT VIEW ALIGNMENT: Step back a few feet and use your eyeballs to make sure the stab is lined up with the wings. If not, youíll need to adjust the top of the fuselage sides until it does.

.

d. Unpin the stabilizer from the fuselage and apply epoxy glue to the joint. Pin the stabilizer back in the exact same spot, using the pencil marks on the bottom as your guide. Recheck the front view alignment and adjust if necessary, using the pins to hold it in correct position until the glue dries. Builderís Tip: We recommend slow drying epoxy glue (not 5 minute) for this joint to allow adequate time to get the stabilizer back in exact alignment before the glue dries.

139.

Pin the vertical fin in position on the stab (without any glue). Locate the two balsa Tail Fairings (sheet 20) and pin them in place along each side of the fin (again no glue). Mark the Tail Fairingís location on the top of the stabilizer with a pencil. This line shows where you will stop the covering on the top of the stab. Remove the fin and tail fairings from the airplane.




140.

Cover the stabilizer and elevators according to the instructions provided with your covering material (see covering instructions further ahead in the book).

141a.

Refer to the plans and then mark the locations for the SIG Easy Hinges on the stabilizer and elevator. Carefully cut a very shallow slit at the hinge location using a sharp #11 blade in your modeling knife. This first slit should be very shallow so you can better control the direction of the knife. Itís main purpose is to establish the hinge slot in the right location, so concentrate on staying on the marked line. Donít try to cut too deep on the first pass. Make the slit a little wider than the actual hinge.

b.

Now make 3 or 4 more cuts in the slit, going a little deeper each time. As you make additional cuts, concentrate on staying in the slit and aiming straight into the center of wood so that it wonít come out the side of the of the part.

142a.

After the slots have been cut, insert an Easy Hinge halfway into each slot in the stabilizer. If the hinge is difficult to push in, re-insert the knife and move it back and forth in the slot a few more times. DO NOT GLUE THE HINGES IN AT THIS TIME. Now, carefully slide the elevator onto the exposed half of the hinges. You will find it easiest to slide the part onto the hinges at an angle, one hinge at a time. To set the proper amount of gap between the parts simply deflect the control surface to the maximum amount of travel desired in each direction. This will automatically set the proper hinge gap.

b.

Place three or four drops of Thin CA glue directly onto the hinge in the gap. You will notice that the glue is quickly wicked into the slot as it penetrates both the wood and the hinge. Immediately turn the part over and glue the other side of the hinge. Continue this process until you have glued both sides of all the hinges.

CAUTION: SIG Easy Hinges are designed to be used with any THIN CA adhesive. Make sure you are using the thinnest variety. Do not use medium or thick CA, or any other type of glue, on Easy Hinges. Also, never use CA accelerator on Easy Hinges.

143a.

Epoxy the fin securely in place. Do not put any glue on the bottom of the fin post or it may get into the rear tailwheel anchor nut. Be sure to line up the fin straight with the 1/8"x1/4" fuselage top stringer. Use a triangle to make sure that the fin is 90 deg. to the stabilizer. Pin in place and let dry.

b.

Sand the front of FN-2 to blend into the top stringer.

144.

Shape and glue the two balsa Tail Bairings in place. After theyíre glued on and dry, taper the Tail Fairings at the back to blend into the fin post.

145a.

Glue a piece of scrap 1/4" sq. balsa on each side of the fin post, between the tail fairing and the top of the fuselage side. Carve and sand to blend with the fuselage and tail fairing.


b.

Use a sanding block to taper the rear end of the fuselage sides to blend in with the fin post.
Note: In this photo, the right side of the fuselage shows this area before shaping. The left side shows how it should look when it's done.