Piper J-3 Cub Assembly manual Specifications Wingspan................................... 106 in (2692.5mm) Wing Area........................ 1630 sq in (10.52 sq dm) Length............................................. 68 in (1727mm) Weight........................ 14.5–16.5 lb (6.6 kg–7.5 kg) Engine................................... 1.00–1.80 Four-Stroke .................................. 1.00–1.60 Two-Stroke ..........................................20–26cc Gasoline Motor...........
Table of Contents Using the Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Required Tools and Adhesives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 UltraCote Covering Colors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Before Starting Assembly . . . . . . . . . . . . . . .
Using the Manual This manual is divided into sections to help make assembly easier to understand, and to provide breaks between each major section. In addition, check boxes have been placed next to each step to keep track of each step completed. Steps with a single box () are performed once, while steps with two boxes ( ) indicate that the step will require repeating, such as for a right or left wing panel, two servos, etc. Remember to take your time and follow the directions.
Radio and Power Systems Requirements • 4-channel radio system (minimum) w/receiver • Large Servo Arms (JRPA212) (3 pkgs) • 12-Inch Servo Lead Extension (JRPA098) • JR Charge Jack Switch (JRPA004) • 18-inch Servo Lead Extension (JRPA099) (4) • Choke Rings (JRPA029 (2) • Y-harness (Ailerons) (JSP98020) (Required when using 4-channel radio) • DS821 Digital Sport Hi-Torque Servo (JRPS821) (JSP20071) (6) or equivalent The elevator installation will require: Two servos and mixing through the radio Or Two servos a
Warranty Period Exclusive Warranty- Horizon Hobby, Inc., (Horizon) warranties that the Products purchased (the "Product") will be free from defects in materials and workmanship at the date of purchase by the Purchaser. Limited Warranty (a) This warranty is limited to the original Purchaser ("Purchaser") and is not transferable. REPAIR OR REPLACEMENT AS PROVIDED UNDER THIS WARRANTY IS THE EXCLUSIVE REMEDY OF THE PURCHASER. This warranty covers only those Products purchased from an authorized Horizon dealer.
Questions, Assistance, and Repairs Your local hobby store and/or place of purchase cannot provide warranty support or repair. Once assembly, setup or use of the Product has been started, you must contact Horizon directly. This will enable Horizon to better answer your questions and service you in the event that you may need any assistance. For questions or assistance, please direct your email to productsupport@horizonhobby.com, or call 877.504.0233 toll free to speak to a service technician.
Safety, Precautions, and Warnings This model is controlled by a radio signal that is subject to interference from many sources outside your control. This interference can cause momentary loss of control so it is advisable to always keep a safe distance in all directions around your model, as this margin will help to avoid collisions or injury. • Always operate your model in an open area away from cars, traffic, or people. • Avoid operating your model in the street where injury or damage can occur.
Hinging the Control Surfaces Required Parts • Stabilizer (2) • Wing (left and right) • Aileron (left and right) • CA hinge (19) Step 3 • Elevator (2) • Rudder • Fuselage Position the hinge in the stabilizer. The slot in the hinge will align with the hole drilled in the stabilizer. Required Tools and Adhesives • Rotary tool • T-pins • Thin CA • Drill bit: 1/16-inch (1.5mm) Step 1 Use a rotary tool and 1/16-inch (1.
Hinging the Control Surfaces Step 5 Step 7 Apply thin CA to the top and bottom of each of the three hinges. Make sure to saturate each hinge so there is enough CA to wick into the hinge and bond with the surrounding wood. Flex the elevator up and down a number of times to break in the hinges. Note: Do not use CA accelerator on the hinges. The CA must be allowed to wick fully into the hinge to provide the best bond between the hinge and the surrounding wood.
Hinging the Control Surfaces Step 8 Step 9 Repeat Steps 1 through 8, and using five hinges per aileron, hinge the ailerons to the wing panels. Repeat Steps 1 through 8, and using three hinges, hinge the rudder to the fin/fuselage.
Landing Gear Installation Note: In Step 2, leave the screws loose in the gear until all the struts and cross brace are in position. Step 2 Step 4 Secure the wheel collar to the axle by tightening . the setscrew onto the flat of the axle with the included . hex wrench. Use two 4-40 x 5/8-inch socket head screws and two . 4-40 locknuts to attach the shock struts to the main landing gear struts. The cross brace also uses two . 4-40 x 5/8-inch socket head screws and 4-40 locknuts .
Landing Gear Installation Step 6 Step 8 The front and rear hubs will key together when . installed properly. Once installed, use four #2 x 5/8-inch sheet metal screws to secure the hubs together. Check . the rotation of the wheel when installing the screws. . If the wheel does not rotate, loosen the screws slightly until it does. To complete the wheel installation, snap the hub cap . onto the wheel. Step 9 Repeat Steps 3 through 8 to install the remaining wheel.
Stabilizer Installation Required Parts • Fuselage assembly • Stabilizer/elevator (2) 3 • 6 /8-inch (162mm) joiner • #6 washer (4) • Tail wheel assembly • 2-56 nut (4) • 4-40 locknut (3) • Large strut support bracket (2) • Small strut support bracket (2) • #6 x 5/8-inch sheet metal screws (2) • 4-40 x 5/8-inch socket head screw (3) • Support rod w/clevis, 10-inch (254mm) (2) • Support rod w/clevis, 9 1/2-inch (241mm) (2) • 6-32 x 3/4-inch socket head screw (4) Step 2 Slide the stabilizer into the slot in
Stabilizer Installation Step 4 Step 6 Attach the tail wheel assembly to the fuselage using two #6 x 5/8-inch sheet metal screws. The forward screw goes through the gear and into the fuselage, while the rear screw goes through the two large strut support brackets, then through the gear and into the fuselage. Remove the clevis from each of the support rods. Use a hobby knife to clean the paint from the threads. Thread a 2-56 nut onto the threads, then replace the clevis.
Stabilizer Installation Step 8 Clip the clevis to the strut support bracket. It will be necessary to adjust the position of the clevis to ensure the support rods are not causing any twists between the fuselage, stabilizer and fin. Tighten the nuts against the clevises once all adjustments have been made. Note: Use threadlock on the nuts and clevises to prevent them from vibrating loose in flight.
Aileron Servo Installation Required Parts • 4-40 metal clevis (4) • 4-40 nut (4) • Wing panel (right and left) • Servo hatch cover (right and left) • 2-56 x 1-inch machine screw (6) • 4 3/4-inch (120mm) pushrod (2) • #2 x 1/2-inch sheet metal screw (8) • Nylon control horn w/backplate (2) • 3/4 x 11/16 x 7/16-inch (19 x 17 x 11mm).
Aileron Servo Installation Step 4 Step 7 Repeat steps 1 through 3 to prepare the remaining cover while the epoxy cures. Use string or a commercially available connector to secure a 18-inch (457mm) servo extension to the servo lead. Step 5 Position the servo between the block and with a small space between the servo and cover. Use a felt-tipped pen to mark the locations for the servo mounting screws onto the blocks. Step 8 Tie a weight to a 24-inch (610mm) piece of string.
Aileron Servo Installation Step 9 Step 10 Tie the string to the end of the servo extension and use it to pull the extension through the wing. Use a piece of tape to keep the extension from falling back into the fuselage. Position the servo hatch cover and secure it using four #2 x 1/2-inch sheet metal screws. After installing the screws, remove them and apply a few drops of thin CA to the holes to harden the wood to prevent the screws from vibrating loose.
Aileron Servo Installation Step 12 Step 14 Attach one end of the linkage to the servo horn. Remove the backplate from a nylon control horn and attach the other end of the linkage to the horn. Position the horn on the aileron with the holes in the horn aligned with the hinge line of the aileron. Use a felt-tipped pen to mark the location for the three control horn mounting screws. Secure the control horn to the aileron using three 2-56 x 1-inch machine screws and the control horn backplate.
Radio Installation Required Parts • Fuselage assembly • 4-40 nut (4) • Metal clevis (4) • Rudder cable • Rigging couplers (4) • Cable crimps (4) • 2-56 nuts (3) • Rudder spring (2) • Rudder tiller bracket • Radio tray cover • Safety fuel tubing (4) • Rado tray cover • 2-56 x 5/8-inch machine screw (9) • Hook and loop strap (2) • #2 x 5/8-inch sheet metal screw (4) • 33 1/4-inch (845mm) elevator pushrod (2) • 4-40 ball end w/hardware (4) • Control horn w/backplate (4) Required Tools and Adhesives • Drill • L
Radio Installation Step 5 Step 7 Remove the backplate from a control horn. Attach the clevis to the horn and position the horn on the elevator with the holes in the horn aligned with the elevator . hinge line. The horn cenerline will be 1-inch (25mm) . from the edge of the stabilizer to avoid interferrence between the control linkage and mounting tabs. Use a . felt-tipped pen to mark the positions for the three control horn mounting screws.
Radio Installation Step 9 Install the elevator servo into the fuselage. The output arm on the servo faces toward the rear of the fuselage. Secure the servo horn to the servo using the hardware provided with the servo. Note: The cable will be installed into the fuselage from the tail to make the servo end of the cable easier to install, and to keep it from falling into the fuselage while installing the ends and servo.
Radio Installation Step 12 Step 15 Thread a rigging coupler into one of the 4-40 ball ends. Slide a crimp onto the cable, then pass the cable through the rigging coupler. The cable then goes back through the crimp. Use a crimping tool or vice grips to secure the crimp to the cable. Install the rudder servo into the fuselage and attach the servo horn to the servo using the hardware provided with the servo. The output of the servo faces the front of the fuselage.
Radio Installation Step 17 Step 18 The rudder uses two control horns mounted on either side. Position one horn so it is aligned with the mark made in the previous step. Mark and drill the holes for . the control horn screws, then mount the horns. The three . 2-56 x 5/8-inch machine screws go through the first control horn, through the rudder, through the second horn and are then secured using three 2-56 nuts. Slide a piece of safety tubing on a metal clevis.
Radio Installation Step 20 Step 23 Connect the rudder tiller bracket to the tailwheel steering arm using the two rudder springs. You will need to bend the springs to attach them on each end using pliers. Install a choke ring (JRPA029) on each of the the . 18-inch (457mm) aileron extensions that are plugged . into the receiver. These will be hidden under the radio . tray. This is strongly recommended due to all the metal struts on the Cub.
Engine Installation (Glow) Required Parts • Fuselage assembly • Firewall template • Engine mount (2) • #8 washer (12) • 8-32 locknut (4) • Throttle pushrod • Throttle pushrod tube • Metal clevis (2) • Battery cover • #4 washer (4) • 8-32 blind nut (4) • Cowl screw fuel tubing (4) • 4-40 x 1/2-inch socket head screw (4) • #2 x 1/2-inch sheet metal screw (2) • Threaded rod, 1-inch (25mm) (2) • 8-32 x 1 1/4-inch socket head screw (4) • 8-32 x 1 1/2-inch socket head screw (4) Required Tools and Adhesives • Dril
Engine Installation (Glow) Step 4 Step 6 Position the engine on the mount so the drive washer is 6 inches (152mm) forward of the firewall. Clamp the engine to the mount and transfer the locations for the engine mounting bolts onto the engine mounts. Slide the throttle pushrod tube into the hole drilled in the firewall. The tube will extend forward of the firewall slightly. Use medium CA to glue the tube to the firewall.
Engine Installation (Glow) Step 8 Step 11 Thread a 1-inch (25mm) threaded rod into each end of the throttle pushrod. Thread a metal clevis onto one of the threaded rods and slide the pushrod into the pushrod tube. Attach the clevis to the arm of the carburetor. Slide the fuel tank into the fuselage with the stopper facing toward the top of the fuselage. Use a rubber band to keep the fuel tank from moving rearward in the fuselage.
Engine Installation (Glow) Step 13 Step 14 Install the muffler and connect the fuel lines from the tank to the engine. Attach the cowling using four 4-40 x 1/2-inch . socket head screws, four pieces of cowl screw tubing . and four #4 washers. Install the propeller to complete . the engine installation. Note: We used a fuel dot and T-fitting on our model so the cowl won't have to be removed to fuel the engine.
Engine Installation (Gas) Required Parts • Fuselage assembly • Firewall template • Throttle pushrod tube • Metal clevis (2) • Battery cover • #4 washer (4) • Cowl screw tubing (4) • Throttle pushrod • Fender washer (4) • Ignition switch (JRPA004) • 10-32 x 5/8-inch bolt (4) • 4-40 x 1/2-inch socket head screw (4) • #2 x 1/2-inch sheet metal screw (2) • Threaded rod, 1-inch (25mm) (2) • 38mm engine stand-offs (EVO3307) Required Tools and Adhesives • Drill • Clamp • Medium CA • Phillips screwdriver • Threadlo
Engine Installation (Gas) Step 7 Slide gas compatible fuel lines back onto the brass . tubes. Use fine wire to secure the fuel lines. The wire . is placed behind the solder applied in the previous step . to keep the tubes in place. Step 5 Secure the throttle servo in the fuselage using the hardware provided with the servo. Thread a clevis onto the threaded rod and attach the clevis to the servo arm. Step 8 Carefully insert the stopper assembly into the fuel tank.
Engine Installation (Gas) Step 9 Step 11 Slide the fuel tank into the fuselage with the stopper facing toward the top of the fuselage. Use a rubber band to keep the fuel tank from moving rearward in the fuselage. Trim the cowling as necessary to clear the muffler, carburetor and head of the engine. Secure the cowling using four 4-40 x 1/2-inch socket head screws, four pieces of cowl screw tubing and four #4 washers.
Interior Detail Installation Required Parts • Fuselage assembly • Front windscreen • Side window (left and right) • Upper window • Front seat bottom • Front seat back • Rear seat bottom • Rear seat back • Floor • Instrument panel • Windscreen supports • Hook and loop • Pilot • #2 x 1/2-inch sheet metal screw (4) Step 3 Plug the switch harness into the battery and receiver. Slide the rear seat into position, guiding the wires from the switch harness behind the seat.
Interior Detail Installation Step 5 Step 7 Use four #2 x 1/2-inch sheet metal screws to secure the floor into the fuselage. The floor will keep the seats from sliding in the fuselage. Use 30-minute epoxy to glue the windscreen supports into position as shown. Step 6 Use medium CA to glue the instrument panel into . the fuselage 34 Step 8 Use canopy glue to glue the front windscreen onto the fuselage as shown.
Interior Detail Installation Step 9 Step 12 Use a hobby knife and hobby scissors to trim the side windows. Use canopy glue to attach the side windows . into position. Complete the window installation by trimming and installing the upper window in the fuselage. Step 10 Trim the rear window and use canopy glue to secure the rear window in position. Step 13 Use hook and loop to secure the pilot in the fuselage. Step 11 Repeat Steps 9 and 10 for the opposite side windows.
Wing Installation Required Parts • Wing (left and right) • Short strut pin (4) • Mid-span stud (4) • 4mm nut (4) • Wing strut end (4) • Long strut pin (4) • Retainer clip (8) • Aluminum wing tube • Wing strut wing bracket • 4-40 locknut (8) • 1/4-20 nylon wing bolt (2) • Mid-span cross brace (2) • 4-40 x 3/4-inch socket head screw (8) • 4-40 x 3/8-inch socket head screw (4) • 4-40 x 1/2-inch socket head screw (4) • Front wing strut (left and right) • Rear wing strut (left and right) Required Tools and Adhes
Wing Installation Step 4 Step 6 Thread the wing strut ends and 4mm nuts on the ends . of the struts. Slide the aluminum wing tube into the fuselage. The wing is then slid onto the wing tube. Plug the servo lead in the wing into the extension inside the fuselage. Step 5 Install the mid-span supports and cross brace as shown. The brace and supports attach using two 4-40 x 3/8-inch socket head screws and 4-40 locknuts.
Wing Installation Step 8 Step 9 Confirm that there is a piece of tubing on the pin before inserting it into the brace. If not, install a piece of tubing to prevent vibration and radio interferrence. Slide the . short pins from the strut ends into the brace at the fuselage. It will be necessary to adjust the strut ends . to align without binding or twisting the wing. Once adjusted, tighten the 4mm nuts against the ends to . prevent them from changing position.
Control Throws The amount of control throw should be adjusted as closely as possible using mechanical means, rather than making large changes electronically at the radio. By moving the position of the clevis at the control horn toward the outermost hole, you will decrease the amount of control throw of the control surface: moving it toward the control surface will increase the amount of throw; moving the pushrod wire at the servo arm will have the opposite effect.
Pre-Flight Charge both the transmitter and receiver pack for your airplane. Use the recommended charger supplied with your particular radio system, following the instructions provided with the radio. In most cases, the radio should be charged the night before going out flying. Check the radio installation and make sure all the control surfaces are moving correctly (i.e. the correct direction and with the recommended throws).
Building and Flying Notes 41
2007 Official AMA National Model Aircraft Safety Code GENERAL 1. A model aircraft shall be defined as a non-humancarrying device capable of sustained flight in the atmosphere. It shall not exceed limitations established in this code and is intended to be used exclusively for recreational or competition activity. 2. The maximum takeoff weight of a model aircraft, including fuel, is 55 pounds, except for those flown under the AMA Experimental Aircraft Rules. 3.
2007 Official AMA National Model Aircraft Safety Code Radio Control 1. All model flying shall be conducted in a manner to avoid over flight of unprotected people. 2. I will have completed a successful radio equipment ground-range check before the first flight of a new or repaired model aircraft. 3. I will not fly my model aircraft in the presence of spectators until I become a proficient flier, unless I am assisted by an experienced pilot. 4.
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