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wing. The holes in the wing ends of the struts should be
positioned so they will align with the hardwood blocks in the
wing.

Do not drill into the wing or fuselage at this time.

❏ ❏

3. Position the strut on the fuselage and wing. Drill a 3/32"

[2.4mm] hole at the fuselage and the 

front strut mount

only.

Do not drill the hole for the rear strut mount at this time.

❏ ❏

4. Thread a #4 x 1/2" sheet metal screw into the fuselage

and front wing strut mount block. Remove the screws and
place three drops of thin CA into the holes to harden the
threads. Wait until the CA has cured before you continue.

❏ ❏

5. Attach the strut using two #4 x 1/2" sheet metal

screws and two #4 washers.

The following steps are necessary to install the struts so
they do not twist the wing. Work slowly and carefully,
checking the alignment until you are confident the strut will
not twist the wing when attached.

❏ ❏

6. Place your Cub upside-down in an aircraft stand.

Place a level (or incidence meter) on the wing near the
fuselage. Adjust the position of the airplane until the root of
the wing is perfectly level.

❏ ❏

7. Move the level (or incidence meter) out to the tip of

the wing without allowing the position of the main aircraft to
change. Use the level to check the wing to make sure it is
not twisted. If so, carefully twist the wing until it is level.

❏ ❏

8. Once level, mark the location of the rear strut

attachment through the hole in the strut. Remove the strut and
drill the marked location using a 3/32" [2.4mm] drill bit. Follow
the procedure in step 4 to harden the hole for the screw.

9. Repeat steps 2 through 8 to install the remaining strut.

IMPORTANT: The struts are necessary to safely fly
your Cub. It must not be flown without them installed
under any circumstance.

20

Summary of Contents for Piper j-3 cub

Page 1: ...umed nor accepted for any damage resulting from the use by the user of the final user assembled product By the act of using the user assembled product the user accepts all resulting liability If the buyers are not prepared to accept the liability associated with the use of this product they are advised to return this kit immediately in new and unused condition to the place of purchase READ THROUGH...

Page 2: ...property To make your R C modeling experience totally enjoyable we recommend that you get experienced knowledgeable help from an instructor with assembly and during your first flights You ll learn faster and avoid risking your model before you re truly ready to solo Your local hobby shop has information about flying clubs in your area whose membership includes qualified instructors You may also co...

Page 3: ...ding HCAQ1000 Fueling System Great Planes Top Fueler GPMQ4160 8 32 Tap 29 Drill Bit GPMR8103 These are the building tools that are required We recommend Great Planes Pro CA and Epoxy glue 2 oz Pro CA Thin GPMR6003 2 oz Pro CA Medium GPMR6009 CA Accelerator GPMR6035 6 Minute Pro Epoxy GPMR6045 30 Minute Pro Epoxy GPMR6047 Canopy Glue JOZR5007 Hobby Knife HCAR0105 Blades HCAR0311 Builders Triangle S...

Page 4: ...ll securely bond the covering to the wood so the wrinkles will be less likely to reappear in the future AMA Academy of Model Aeronautics ARF almost ready to fly Deg degrees Elev elevator Fuse fuselage inches LE leading edge Ply plywood Stab stabilizer TE trailing edge LG landing gear mm millimeters 1 64 4mm 1 32 8mm 1 16 1 6mm 3 32 2 4mm 1 8 3 2mm 5 32 4mm 3 16 4 8mm 1 4 6 4mm 3 8 9 5mm 1 2 12 7mm...

Page 5: ...ing Struts 2 19 Elevator Joiner Wire 1 20 Dummy Engine 1 21 Wing Joiners 3 22 Landing Gear Fairing Mounts 2 23 Wing Dowels 2 24 Pushrods 1 Set Parts Not Shown In Photo Description Qty Adjustable Engine Mount 1 Main Wheels 2 Servo Tray 1 CA Hinge Strip 2 x 9 1 Hardware Bag 1 Replacement Parts If needed replacement parts for Piper Cub ARF are available through your hobby supplier Wing Set GPMA2180 F...

Page 6: ...so there is no gap when you join them Since the wing is built with no dihedral it can be built flat on your work surface Make a dry run of the following step without using any glue so you will know how to clamp your wing together 4 Tape a piece of wax paper or plan protector over your work surface Thoroughly coat the joiner pockets and the mating ends of both wing halves with 30 minute epoxy Set t...

Page 7: ...ing holes without moving the rails 6 Position the engine on the engine mount rails so the propeller thrust washer is 5 1 4 133mm ahead of the firewall Use a Great Planes Dead Center Hole Locator GPMR8130 not included or a sharpened piece of wire to scribe the four engine mount holes onto the rails Use a center punch at the marks to prevent the drill bit from wandering then drill 29 pilot holes thr...

Page 8: ...nt of epoxy to fuelproof the cowl mounting blocks 1 Cut the clear pick up tube included with this kit to a length of 3 3 16 81mm Assemble the fuel tank as shown in the sketch using the 90 degree nipple After you assemble the tank hold it up to the light and make sure the clunk does not contact the rear of the tank If necessary disassemble the tank and shorten the pick up tube 2 Wrap the tank with ...

Page 9: ...a mark on the wing and fuselage so it can be repositioned accurately for the following steps 4 Remove the covering from the wing center section where the wing bolts will pass through the wing 5 Bolt the wing to the fuselage using the 1 4 20 x 2 Nylon Bolts Enlarge the holes if necessary to allow the bolts to pass through the wing Check the alignment of the wing and enlarge the holes in the wing if...

Page 10: ...enter of the firewall in the front of the fuselage Tie a small loop at one end of a 42 1070mm piece of monofilament string and slip it over the T pin 5 Fold a piece of masking tape over the other end of the string and draw an arrow on it Slide the tape along the string and align the arrow with one end of the stab Swing the string over to the other end of the stab while keeping the stab centered in...

Page 11: ...to glue the stab to the fuse Position the stab in the fuse so the exposed balsa of the center section is visible Apply a film of 30 minute epoxy to the bare balsa on both sides of the stab and slide it into position making sure you distribute enough epoxy in the opening Repeat this procedure once more to make sure you have distributed plenty of epoxy in the stab saddle Recheck alignment using the ...

Page 12: ...lage is upside down in your cradle If necessary bend the tail gear wire so your model will taxi straight when your rudder is centered 1 Use a fresh 11 blade to trim the covering from the slot in the fuselage for the main landing gear 2 Test fit the Main Landing Gear It s helpful if you use a file to remove any burrs or sharp edges from the ends of the wire Seat the landing gear wire in the landing...

Page 13: ...s using four 7 32 Wheel Collars and four 8 32 Set Screws Drill the hub of the wheels using a 7 32 5 6mm drill bit if necessary so they fit onto the axle Grind or file a flat spot at the point of set screw contact This provides a better area for the set screw to bite and helps keep the wheel in place Trim off any excess axle wire after installing the wheel collar Use threadlock on the set screws to...

Page 14: ...icult to install or don t go in far enough carefully enlarge the hinge slots with a hobby knife and a 11 blade 3 Drill a 3 32 2 4mm hole 1 2 13mm deep in the center of the hinge slot If you use a Dremel MultiPro for this task it will result in a cleaner hole than if you use a slower speed drill Drilling the hole will twist some of the wood fibers into the slot making it difficult to insert the hin...

Page 15: ...bber grommets and eyelets in your aileron servos Attach a servo extension to the aileron servo Use heat shrink tubing or electrical tape to secure the servo cord to the extension so they don t unplug in flight Pull the string part way out of one of the aileron servo compartments in the wing Tie the string to the servo cord on one of the aileron servos 2 Fit one of the aileron servos in the wing Ho...

Page 16: ... 13mm holes in the bottom center section of the wing to retrieve your aileron servo cords Connect both aileron servo cords to a Y harness 1 Use the following sequence for mounting the servos into the servo tray in the fuselage A Install rubber grommets and brass eyelets in the servos as shown in the sketch above B Test fit the servos in the tray Enlarge the openings if needed to create a 1 32 8mm ...

Page 17: ...nto the radio compartment The tubes must protrude at least 1 1 2 38mm from the fuse side exits 4 Cut the pushrod tubes 1 1 2 38mm behind the servo openings in the servo tray 5 Insert one of the 4 40 x 36 910mm Threaded End Rods into the rudder tube in the fuselage The pushrod should slide easily into the tube Screw a 4 40 nut and a 4 40 steel clevis on the pushrod and add a silicone retainer to th...

Page 18: ... tube from the servo compartment Attach the clevis to the outer hole of the servo arm Thread the nut and clevis back onto the pushrod wire and attach the clevis to the rudder control horn 9 Repeat steps 5 through 8 to assemble and install the elevator pushrod 10 A pushrod brace must be installed to prevent the pushrods from flexing near the servos We used 1 4 balsa to make the brace shown This bra...

Page 19: ... into a container Let it sit for about an hour or two to allow the damaging elements to boil off Using an air brush you may now spray your windshield with your specially prepared LustreKote For airbrushing we recommend thinning LustreKote with lacquer thinner If you prefer to spray your windshield frame directly from a spray can we have had success with Pactra Formula U and Chevron paint Always te...

Page 20: ... carefully checking the alignment until you are confident the strut will not twist the wing when attached 6 Place your Cub upside down in an aircraft stand Place a level or incidence meter on the wing near the fuselage Adjust the position of the airplane until the root of the wing is perfectly level 7 Move the level or incidence meter out to the tip of the wing without allowing the position of the...

Page 21: ...ric measurements Route the antenna to the tail of the model You may use your preferred method or the method we use in the Great Planes model shop Drill a 1 4 6mm hole through the fuse side in the proximity of the receiver Cut a 1 2 13mm long piece of fuel tubing and install it in the hole Install a strain relief as shown in the sketch then route the antenna through the fuel tubing to the bottom of...

Page 22: ...ll the clevises Charge the Batteries Follow the battery charging procedures in your radio instruction manual You should always charge your transmitter and receiver batteries the night before you go flying and at other times as recommended by the radio manufacturer Balance the Propeller Carefully balance your propellers before flying An unbalanced prop is the single most significant cause of vibrat...

Page 23: ...ndition so fuel will not leak onto a hot engine causing a fire To stop a glow engine cut off the fuel supply by closing off the fuel line or following the engine manufacturer s recommendations Do not use hands fingers or any other body part to try to stop the engine Do not throw anything into the propeller of a running engine Read and abide by the following Academy of Model Aeronautics Official Sa...

Page 24: ...erforming most any manuever however you can expect some roll coupling with rudder when attempting knife edge maneuvers Full throttle snaps are not recommended due to the extremely high stresses they place on the structure Sometime well before it s time to land you should climb your Piper Cub to a safe altitude cut the throttle to an idle and check out the model s low speed characteristics Do this ...

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