TWEETY 25 Almost Ready to Fly Nitro/Electric Aerobat INSTRUCTION MANUAL SPECIFICATIONS FEATURES WINGSPAN: 45.7 (1160mm) LENGTH: 38.6 (980mm) WING AREA: 370 sq in(24 sq dm) FLYING WEIGHT: Approx. 3.3 lbs (1500g) SUGGESTED POWER SYSTEM: GForce G15(3542) Brushless Electric Motor or.15 25 Nitro Motor SUGGESTED RADIO SYSTEM: 4 CH, 4 5 Standard Servos Light weight laser cut ply and balsa construction. Detachable fuselage hatch for easy access of battery and electronics. Conveniently powered by either an electric or a nitro motor. Pre covered in high visibility trim scheme.
WARNING This radio controlled model is NOT a toy and NOT intended for person under 16 years old. Keep this kit out of reach of younger children, as it contains parts that could be dangerous. A radio controlled model is capable of causing serious bodily injury and property damage. It is the owner's responsibility to assemble the aircraft properly. Test fly your model in the presence of an experienced RC modeler. Your model must always be operated and flown using great care and common sense, as well as in accordance with the safety code of the AMA or MAAC. We suggest you purchase proper insurance prior to flying this model. The FCC requires that you use only radio frequencies specified for R/C model aircraft. Do not at any time fly this model while under the influence of drugs or alcohol. Parts of the Airplane 1. Fuselage 2. Fin and rudder 3. Wing 4. Horizontal stabilizer and elevator 5. Canopy
Included Hardware Please note the following abbreviations used in this manual about fasteners: 1. CM means socket head screws, e.g. CM4 means 4mm socket head screws 2. PWA means self tapping screws, e.g. PWA2/PWA3 means 2 or 3mm self tapping screws 3. PM means round head machine screws, e.g. PM4 4mm round head machine screws 4. Ф1.8X600mm means 1.8mm diameter and 600mm length pushrod Qty Qty 1. Rudder pushrod [Ф1.8X600mm] 2 16. Round head machine screws (securing 2 2. Elevator pushrod [Ф1.8X600mm] 2 wings to Fuselage) [PM3X30mm] 3. Throttle pushrod [Ф1.5X300mm] 1 17. Round head machine screws for securing 2 4. Aileron pushrod [Ф1.8X150mm] 2 landing gear [PM3X20mm] 5. Elevator joiner wire [Ф2X84mm] 1 18. Pushrod EZ connector for throttle servo 1 6. Tail wheel assembly 1 [Ф2.1mm] 7. Fuel tank 1 19. Self lock Nuts for securing wheel shaft 4 8. Wing joiner strip 1 [Ф3mm] 9. Electric motor mounting plate 1 20. Control horn 4 10. Wing joiner plate 1 21. Round head machine screws for control 12 11. Fuel tank mounting braces 1 horns [PM2X20mm] 12. Electric motor mounting block 4 22. Self tapping screws for securing Canopy 4 13. Main wheels 2 [PWA3X10mm] 14. Landing gear 1 23. M3 Washer 6 15. Socket head screws for use as main wheel 2 24. Clevises 4 shaft [CM3X35mm] 25. EZ link for pushrod Z Bend 4
Install the Ailerons Step 1: Drill a 1/16 inch hole into the center of each hinge slot in the aileron and wing panel. Trim the covering away from each hinge slot to ensure that the hinges will be properly glued in place. Step 4: Adjust the aileron so there is a small gap between the LE of the aileron and the wing. The gap should be about 1/64 inch or just wide enough to slip a piece of paper through. Step 2: Test fit a CA hinge into each of the hinge slots. If necessary, enlarge the slots with a hobby knife. When satisfied with the fit, place the hinges into the slots. Push a pin through the middle of each hinge to keep them centered. Step 5: Apply six drops of thin CA to the top and bottom of each hinge. Do not use accelerator in the hinging process. The CA must be allowed to soak into the hinge naturally. After the CA has cured, flex the surfaces several times to break in the hinges. Pull on both surfaces to make sure the hinges are secure. Repeat steps 1 5 for the other wing panel. Step 3: Join the aileron to the wing panel and remove the pins from the hinges. Center the aileron on the wing.
Install the Aileron Servos & Pushrods Before installation, confirm that the servos you will be using will properly fit in the servo opening. Make adjustments as necessary for your servos. The pre cut servo openings on this airplane will fit most standard sized servos. ENLARGE TO 2mm CUT OFF UNUSED ARM Step 1: Installing the servos in the wing will require the use of a servo extension wire for each aileron servo. One Y harness connector is also required and is used to allow the aileron servos to plug into one slot in your receiver. You may also have a computer radio that allows you to plug the servos into separate slots and then mix them together with the radio transmitter. If you choose to mix them together with the radio rather than a Y harness, refer to the manual for your particular model radio system. Step 3: Securely tie the string from inside the opening for the aileron servo to the end of the servo extension. Pull the servo wire and extension through the wing. Step 4: Temporarily position the aileron servo into the servo bay. Install and remove a servo mounting screw into each of the four holes. Apply a drop of thin CA into the holes to harden the wood. After the glue has hardened, install the servo into the opening. Cut three arms from a four armed servo arm (arms may need to be purchased separately). Center the servo with your radio system and install a servo arm parallel to the aileron hinge line as shown. Step 2: Attach the servo extension to the aileron servo and secure it with heat shrink tubing. The tubing can be shrunk around the connector with a heat gun or micro torch. If your aileron servo has tabs molded into the case for mounting the servo on its side, they must be cut off in order for the servo to fit into the servo bay in the wing panel. Follow the instructions included with the servo for cutting the tabs. Install the eyelets and grommets included with the servo. Ф1.8X170 mm Nylon Clevis Aileron Pushrod The clevis needs to be secured onto the pushrod for about 8mm 8mm
Step 5: Place one of the nylon control horn on the aileron, positioning it as shown in the sketch and aligning it with the servo arm using a straight edge as a guide. Mark the location for the screw holes. Drill a hole through the aileron at the marks you made. Install and remove the screw into each of the holes. Harden the holes with a drop of thin CA. After the glue has hardened completely, secure the control horn with two screws. Step 7: Use tape or a small clamp to hold the aileron in the neutral position. With the servo arm still parallel to the hinge line, make a mark on the pushrod where it crosses the outer hole in the servo arm. Remove the pushrod and clevis from the control horn and make a 90 degree bend at your mark. Cut off the excess pushrod wire 6mm beyond the bend. Enlarge the outer hole in the servo arm using a 2mm drill bit. Connect the pushrod to the servo arm using a nylon Fast Link. Finish the wing panels Servo Arm Ф1.8X170 mm Aileron Pushrod 6mm Faslink Bend the end of the wire into a right angle. Depending on the length of the wire needed, excess wire can be removed. Step 6: Locate the pushrod wire with threads on one end. Screw a nylon clevis onto the rod. It is recommended you use a clevis retainer (not included) to help keep the clevis in place. Slide a silicone clevis retainer onto the base of the clevis. Connect the clevis to the second hole on the control horn. Step 1: Without using any glue, test fit the wing halves with the wing joiner. Make sure the halves fit together well. If there is a problem with the fit, look for obstructions such as glue bumps or wood slivers inside the wings where the joiners fit. Make any adjustments necessary to get a good fit.
Step 2: Mix a generous amount of 30 minute epoxy. Pour the epoxy into the joiner opening on the wing. Make sure the epoxy is distributed all the way around inside the wings. Use an epoxy brush to coat the root ribs of both wings and one half of the joiner all the way around. Insert the epoxy coated half of the joiner. Wipe away excess epoxy as it is forced out. Step 5: Align the wing bolt plate over the holes on the underside of the wing. With the wing bolt plate centered over the holes, use a sharpie pen to trace around the plate onto the wing. Step 3: Coat the protruding end of the joiner all the way around with epoxy. Join the other wing, press the two halves together, allowing excess epoxy to drip out as you go. When the wings come together, wipe away excess epoxy that is squeezed out, then use a C clamp and several strips of masking tape on both the top and bottom of the wing to tightly hold the two halves together. If epoxy continues to work out of the wing under the tape, remove one strip at a time and wipe off the epoxy, then replace with another strip of tape. Do not disturb the wing until the epoxy has hardened. Step 6: Trim the covering just inside your lines. Wipe away the lines with alcohol and glue the wing bolt plate to the wing. Continue the wing bolt holes through the wing bolt plate with a 1/8" [3.2mm] drill bit. A wood backer piece while drilling will help ensure clean edged holes in the wing bolt plate. Step 4: Locate and remove the covering from the wing bolt holes near the trailing edge of the wing. Step 7: When you are finished installing electronics inside the fuselage, you can install the wing onto the fuselage using two machine screws and two flat washers.
Install the Stabilizer Step 1: Locate the horizontal stabilizer slot under the covering on the tail section of the fuselage by lightly pressing with your finger. The slot is located on both sides of the fuselage. Carefully remove the covering. Make sure you do not cut into the wood. Step 4: Attach a piece of string to measure the distance A of each stabilizer halves, and B the difference between the wing tip and the top of stabilizer. Both distances should be equal. Step 2: Locate the slot for the vertical fin on the top of the fuselage and remove the covering. Make sure you do not cut into the wood. Step 5: With the stabilizer properly aligned, use a felt tip pen to trace a line around the tail of the airplane on the top and bottom of the horizontal stabilizer. Step 3: Insert the stabilizer into the stabilizer slot so it is centered in the fuselage (dimension A should be equal). Place the wing onto the fuselage and secure it in place with the wing hold down bolts. View the plane from the rear and at a distance of a few feet. The stabilizer should be parallel to the wing (dimension B should be equal). If not, sand the stabilizer mounting base slightly to achieve the proper position of the stabilizer. Step 6: Remove the stabilizer and draw two additional lines, top and bottom, 1.6mm inside the lines drawn in the previous step. Using a knife, carefully cut through the covering along the inside lines and remove the covering from the center. Do not cut the wood under the covering!
If the covering is not removed from the stabilizer, a proper bond for your adhesive will not be achieved. Step 7: Mix 30 minute epoxy and spread some inside the horizontal stabilizer mount on the fuselage. Spread more epoxy onto the top and bottom of the stabilizer where the covering was removed. Insert the stabilizer into the fuselage from the rear and adjust the alignment using the guide lines that were drawn onto the stabilizer. Wipe off any epoxy that squeezes out using a paper towel dampened with rubbing alcohol. Recheck the alignment frequently while the epoxy cures. Install the Vertical Fin degree angle between the vertical fin and horizontal stabilizer when viewed from the rear. Use masking tape to hold the vertical fin in this position. Recheck the alignment frequently while the epoxy cures. Install the Elevator Step 1: Find the pre cut hinges from the included accessories. Test fit the hinges in the slots in the elevator halves and stabilizer. If the hinges do not slide into the slots easily, work your knife blade back and forth in the slot a few times to provide more clearance DRILL A 3/32 HOLE DEEP IN CENTER OF HINGE SLOT Step 1: Test fit the vertical fin in the slot in the top of the fuselage. Sand the edges of the slot if necessary to obtain a snug fit. Draw a line around the vertical fin where it meets the fuselage. Cut the covering 1/16 [1.6mm] inside the lines you drew on the vertical fin and the top of the fuselage. Remove the covering. Step 2: Drill a 3/32 [2.4mm] hole, 1/2 [12.7mm] deep in the center of the hinge slots. Reinsert your knife blade to clean out the slot after you drill the holes. Step 2: Mix some 30 minute epoxy and apply it to the top of the horizontal stabilizer through the slot and on the sides of the slot. Apply more epoxy to the vertical fin where the covering was removed. Insert the vertical fin into the fuselage and adjust the alignment. Check for a 90 Step 3: Insert four hinges into the slots in the stabilizer. Press the elevators onto the hinges until the gap between the elevators and stabilizer is about 1/32 [.8mm]. Flex the elevators a little in one direction, but do not allow them to pull away from the stabilizer. Apply six drops of thin CA onto each hinge. Turn the fuselage over and apply six more drops of thin CA to the other side of each hinge. DO NOT use accelerator while hinging, as the CA must wick into the hinge to properly attach the hinges. Use a paper towel to absorb any excess CA. After the CA cures,
flex the elevators in both directions to free up the elevators for operation. Install the Rudder and Tail Wheel Step 1: Assemble the tail wheel assembly set using the included accessories. Step 4: Temporarily insert a pushrod into the elevator pushrod exit slot. Use the position of the pushrod to align the elevator control horns onto the undersides of the elevator halves. Mark the locations of the control horn mounting holes onto the elevator halves and drill holes at the marks. Do not drill all the way through the elevator halves! Thread a screw into the hole and back it out. Apply a couple drops of thin CA glue to the hole and let it harden. Attach the elevator control horns to the elevators using four screws. Step 2: The installation tab of the tail wheel need to be mounted on the bottom of the fuselage. Test fit the rudder to the fuselage with the tail wheel assembly installed in the orientation shown. Make any adjustments necessary so the tab on the tail wheel is securely fastened on the fuse. Roughen the wire on the tail wheel assembly that fits into the rudder with sand paper and clean it off with alcohol. Glue the tail wheel wire into the hole in the
LE of the rudder with medium or thick CA glue. Fit the rudder to the fuselage along with CA hinges. Glue the CA hinges in place with thin CA glue. Step 3: As you did with the elevator, use the pushrod to temporarily position a control horn onto the side of the rudder. Then secure the control horn using two screws. Step 2: Thread the clevis securely onto the rudder pushrod. We recommend using a clevis retainer to help keep the clevis in place. Slide the pushrod through the rudder pushrod exit slot in the fuselage and connect it to the rudder control horn. Installing the Tail Servos and Pushrods Step 1: Install the elevator and rudder servos into the fuselage as shown using the hardware supplied with the servos. Be sure to harden the screw holes with thin CA as was done with the aileron servos. Cut three arms from two four armed servo arms. Center the servos with your radio system and install them onto the servos with the servo screws. Enlarge the outer holes of each servo arm with a 5/64" [2mm] drill bit. Depending on your balancing needs, you can install the receiver battery in the front of the fuselage or at the back of the fuselage. Step 3: With the rudder in the neutral position and the rudder servo arm perpendicular to the pushrod, mark where the pushrod crosses the outer hole of the servo arm. As you did with the aileron pushrods, make a 90 degree bend at the mark and cut off the excess pushrod 1/4" [6mm] beyond the bend. Secure the pushrod to the servo arm with a FasLink. Make any adjustments necessary to the nylon clevis so that the rudder is properly centered and slide the silicone clevis retainer to the end of the clevis.
Step 4: Thread the clevis securely onto the elevator pushrod. We recommend using a clevis retainer to help keep the clevis in place. Slide the pushrod through the elevator pushrod exit slot in the fuselage and connect it to the elevator control horn. Install the Main Landing Gear Step 5: With the elevator in the neutral position and the elevator servo arm perpendicular to the pushrod, mark where the pushrod crosses the outer hole of the servo arm. As you did with the rudder pushrods, make a 90 degree bend at the mark and cut off the excess pushrod 1/4" [6mm] beyond the bend. Secure the pushrod to the servo arm with a FasLink. Make any adjustments necessary to the nylon clevis so that the elevator is properly centered and slide the silicone clevis retainer to the end of the clevis. Step 1: Locate the four blind nuts in the bottom of the fuse. Cut the covering from the inside of the holes. Step 2: Mount the aluminum landing gear to the fuselage.
have been secured, glue the motor mounting plate onto the motor rail. The plate should be secured on the top and bottom by the four triangles. The motor mounting plate has been cut so they should fit properly between the motor rails. After the plate has been secured, glue the two triangle stock onto the side as shown in the photo. Step 3: Mount the two wheel axles. Step 4: Mount the main wheels to the axles with the wheel collars. Brushless Motor and ESC Installation Step1. Locate the parts for assembling the electric motor mount as shown. Step 2: Mix a generous amount of 30 minute epoxy. Next glue the four support triangles onto the motor rail, one on each side and top/bottom. After the four support triangles
Step3. Take the motor mount of your brushless motor, mark the position of the bolt openings. You will need to drill holes on the motor mounting plate for those bolt openings. Step6. Install the prop and spinner/prop adapter. Step4. Install the motor mount that came with your motor onto the motor mounting plate. Then Install your brushless motor onto the motor mount. Make sure the motor spins freely. Step5. Install the ESC inside the motor box or inside the fuselage, depending on the requirement for balancing the CG.
Installing the Fuel Tank (only if you use nitro motor) 12mm touching. The fuel tubing and clunks (fuel pickup) on the carb and fill lines should almost reach the back of the tank but not touch. The clunks must be able to move freely inside the tank when assembled. Adjust the length of the fuel tubing accordingly. When satisfied, tighten the PM3x25mm screw in the stopper to secure it in place (do not over tighten). Mark the side of the tank that must face up when installed in the plane. We also suggest marking the tubes in the stopper. Step 1: The fuel tank can be assembled as a two line system consisting of a vent (pressure) line to the muffler and a carb line. Filling and emptying of the tank would need to be done through the carb line, or an optional fuel fill valve. The tank can also be assembled as a three line system having a vent line, carb line, and fill line. If installing a fill line, puncture the top of the stopper above the sealed off fuel tube hole. The fill and carb lines should extend out 13mm beyond the stopper and the vent line should be bent upwards and left uncut. With the tubes installed in the stopper, the stopper plates loosely in place with the PM3x25mm screw to hold the assembly together. Step 3: Insert the tank into the fuselage with the correct side facing up. The fuel tubing should be routed through the hole in the center of the firewall. Installing the Nitro Motor (only if you use nitro motor) Top o f tank Vent Step 1: Test fit your engine between the wood engine mount rails. Check the position of the engine for necessary offsets. Fill and carb lines Step 2: Fit the stopper assembly into the tank with the vent line pointing toward the top of the tank, but not
on/off switch. If the hole spacing does not fit your switch, you may need to modify the pre cut opening, or mount it in a different location. You can also mount an optional charge jack receptacle below the switch. 11 7mm Step 2: Position the front of the engine drive washer approx 115 120mm from the firewall, depending on the engine you selected. Mark the location of the engine mount bolt holes onto the mount rails using a Dead Center Hole Locator. Remove the engine from the mount rails and create threads in the four mounting holes. Attach the engine to the mount. Balancing the Model After you have finished building the model into ready tofly condition you can set the C.G. of the model. You need to have all of the systems installed before you begin, including the nitro engine or electric motor, landing gear, radio system, and battery pack. Installing the Receiver The C.G. is located 64mm back from the leading edge of the wing at the fuselage. This is where your model should balance for the first flights. Later you may wish to experiment by shifting the C.G. forward or back to change the flying characteristics. Moving the C.G. forward may improve the smoothness and stability, but the model may then require more speed for takeoff and make it more difficult to slow for landing. Moving the C.G. aft makes the model more maneuverable, but could also cause it to become too difficult to control. Step 1: Secure your receiver inside the fuselage. Then connect the servos to your receiver. Make sure the leads to not interfere with any of the pushrods. When balancing your model, support the plane upright at the C.G. position on the bottom of the wing with your fingers or a commercially available balancing stand. Move the battery or receiver inside the fuselage as necessary so the model hangs level or slightly nose down. This is the correct balance point for your model. After the first flights, the CG position can be adjusted for your personal preference. Step 2: Pre cut openings are provided for mounting an
Setting Control Throws Turn on the transmitter and receiver. Use a ruler to adjust the throw of the elevator, ailerons and rudder. Adjust the position of the pushrod at the control horn to achieve the following measurements when moving the sticks to their endpoints: Aileron Low Rate Up 9mm Down 9mm Aileron High Rate Up 16mm Down 16mm Elevator Low Rate Up 10mm Down 10mm Elevator High Rate Up 16mm Down 16mm Rudder Low Rate Up 12mm Down 12mm Rudder High Rate Up 20mm Down 20mm These are general guidelines for control throws. You can experiment with higher rates to match your preferred style of flying.