Yak-55 46” - Assembly Manual

Thank you for purchasing this 3DHobbyShop aircraft.

If you have any issues, questions, concerns or problems during assembly, please contact our tech

department at: info@3DHobbyShop.com or 1-717-814-5316 10am-4pm Eastern Time, Monday-Thursday.

We highly recommend www.RCGroups.com as a good source for RC tips, tricks, and information.

SAFETY NOTICE: Assembly

During assembly of this aircraft, you will be asked to use sharp knives and hobby adhesives. Please follow all safety procedures recommended by the manufacturers of the products you use, and always follow these important guidelines:

ALWAYS protect your eyes when working with adhesives, knives, or tools, especially power tools. Safety glasses are the best way to protect your eyes.

ALWAYS protect your body, especially your hands and fingers when using adhesives, knives, or tools, especially power tools. Do not cut toward exposed skin with hobby knives. Do not place hobby knives on tables or benches where they can roll off or be knocked off.

ALWAYS have a first-aid kit handy when working with adhesives, knives, or tools, especially power tools.

ALWAYS keep hobby equipment and supplies out of the reach of children.

IMPORTANT NOTE – We strive to provide the absolute best-quality ARF aircraft on the planet. However, the ultimate success or failure of this aircraft is dependent upon proper assembly by you. If you have questions about an assembly step, please contact us, or read the assembly thread for your airplane on RCGroups.com before proceeding. It is always better to slow down and be sure of your assembly than to rush through it and make a mistake which can cause a crash.

SAFETY NOTICE: Flying

This is NOT a toy! It is a very high-performance RC airplane capable of high speeds and extreme maneuvers. It

should only be operated by a competent pilot in a safe area with proper supervision.

ONLY fly your aircraft in a safe, open area, away from spectators and vehicles–and where it is legal to fly. NEVER fly

over an unsafe area, such as a road or street. NEVER fly near overhead power or utility lines. If your airplane ever

becomes stuck in a line or a tree DO NOT attempt to retrieve it yourself. Contact the authorities for assistance in

retrieving your aircraft. Power lines are DANGEROUS and falls from ladders and trees CAN KILL! Never fly too close

to yourself or spectators. Spinning propellers are DANGEROUS! Never run your motor inside a house or building with

the propeller attached – Remove the prop for safety. Always fly within your control. Always follow manufacturer’s

instructions for your radio system. Always obtain proper insurance before flying – contact the AMA at

www.modelaircraft.org

-- READ ALL ASSEMBLY INSTRUCTIONS COMPLETELY BEFORE STARTING ASSEMBLY! --

REQUIRED ITEMS CA Glue (thin and thick) - Hobby Knife - Small Phillips Screwdriver Set - Metric Allen Wrenches - Scissors - Small Pliers - Wire Cutters - Masking Tape. Heat gun is optional.

UNPACKING Unpack your airplane and examine the components. Check for damage of any kind. If you have damage, please contact 3DHobbyShop to discuss.

WRINKLES Your airplane was packed in plastic at the factory without any wrinkles in the covering. You may notice some wrinkles now; more likely, you will notice a few in a day or two or the first time you take the plane out to the flying field. These wrinkles are the result of wood shrinkage and/or expansion. Balsa wood changes size and shape slightly as it is exposed to varying humidity in the air. This is a natural property of balsa wood. As your airplane adjusts to the weather in your part of the world, wrinkles may appear and disappear. Wrinkles may be removed with the gentle application of heat to the covering material on your airplane. The best tool to use is a hobby heat gun. Apply the heat gently: the covering material will shrink as you apply the heat, and this will remove the wrinkles. BE CAREFUL! Too much heat applied too quickly can damage the covering, either by causing it to pull away from the wood at seams and corners or even by melting it. The covering will shrink at low temperature with patient application of heat.

Wrinkles in the covering DO NOT affect flight performance.

IMPORTANT: Remove the canopy before attempting to use heat on your covering! The canopy is made of thermo-activated plastic and WILL deform with the application of heat. Do not apply heat to the canopy.

CLEANING If you need to clean your airplane, we recommend using a damp towel. The paint used on the canopy and cowl is not safe for all cleaners. In particular, DO NOT use alcohol on these parts, it will remove the paint.

ASSEMBLY -- Locate the wheels, wheel axles and axle nuts, wheel collars, and wheel pants. Fit the wheel onto the axle. Install the wheel collar to retain the wheel onto the axle, as shown. Use the axle nut to affix the wheel/axle/pant assembly onto the gear leg, as shown, use included wrench to hold axle.

-- Install the landing gear legs into the fuselage with the shorter of the provided 3mm screws as shown below.

-- Using a sharp hobby knife, remove the covering on both sides of the fuselage as shown below, for the wing spar tube, the aileron servo wire access, anti-rotation pin and wing retaining screw.

-- Remove the covering over the horizontal stabilizer slot, on both sides with a sharp hobby knife.

 

 

 

 

 

 

-- Slide the horizontal stabilizer into the fuselage slot. Use a ruler to measure each side to make sure that it is centered. -- Locate the carbon wing-spar tube and slide it into the fuselage. Measure each of the rear corners of the stabilizer to the wing tube as shown. Adjust the stabilizer until each side measures exactly the same to correctly align the stabilizer.

-- Apply thin CA glue to the joint of the horizontal stabilizer and fuselage as shown. Allow the thin CA to run along the joint and wick into the joint. NOTE: it is not necessary to remove any covering on the stabilizer.

 

 

 

-- Locate the elevator half that has the joiner rod attached -- Slide the elevator onto the stabilizer, inserting the elevator joiner rod through the fuselage cutout as shown. DO NOT GLUE THE HINGES YET -- Make sure the elevator can flex up 45 degrees and down 45 degrees easily. You can easily make a tool to measure 45 degrees by folding a piece of paper as shown.

 

 

 

 

 

 

 

 

 

 

 

-- Once you are satisfied that your elevator can move easily 45 degrees up and 45 degrees down, put two drops of thin CA glue on each hinge to glue the elevator permanently to the stabilizer as shown.

-- Next place a small piece of tape on the elevator and stab as shown to hold the elevator perfectly straight and level to the stabilizer.

 

-- Now install the other side elevator without glue. Make sure that the elevator is straight and level to the stabilizer like the first elevator. If not, if the elevator shows a slight twist, you can take a little time and sand or trim the slot that the elevator joiner rod fits into to correct this. A slight twist in the elevators will not affect flight performance, but it may bother you, so this is the right time to correct it if necessary. -- Once you are satisfied with the alignment of the elevator, remove it and put thick CA glue in the joiner slot as shown. Re-install it onto the stab and joiner rod, and put two drops of thin CA glue on each hinge.

 

 

 

-- Using THIN CA glue, go over the motor box assembly, applying a small amount of glue to all the seams. This is the highest-stress area of the airframe, and we want to make it as strong as possible. -- Your airplane includes a pre-drilled firewall with pre-installed blind nuts that fit Omega, Torque, Hacker, and other popular brands of brushless motors. If your brand of motor uses a different bolt pattern, use your hobby knife to carefully remove the blind nuts and plywood circle spacers from the back of the firewall, and then re-drill the firewall for your motor. -- Assemble brushless outrunner motor as shown below for mounting in front of the firewall surface. The prop adaptor should be on the OPPOSITE side of the motor from the mount. Install motor with the longer 3mm screws as shown. Please note that the motor is installed IN FRONT of the firewall. NOTE: Your kit contains 4 plastic motor mount spacers. They may be used to space the motor away from the firewall as needed for cowl clearance. Short motors, such as the Omega 103g1030KV, Hacker A30-16M, or Torque 2818-T900 require the spacers. Longer motors, such as the Omega 130g870KV, Torque 2814-T820 do not require the spacers. -- Install speed control to fuselage with short velcro strip or zip ties.

 

-- Install the canopy hatch onto the model and seat it in place. Place some tape across the front of the hatch. -- Tape small strips of paper over the cowl-mounting tabs as shown below and mark with pen or hobby knife the location of the cowl mounting screws over the ply mounting tabs.

-- Making sure to slide the cowling underneath the taped pieces of paper, slide the cowling onto the front of the plane as shown below. -- Holding the cowling in place with tape, take your time to align the cowling on the fuselage. Measure vertically and horizontally from the edge of the front of the cowling to the motor to ensure that the cowling is centered as shown.

-- When the cowling is aligned and centered, using a hobby knife or fine drill, start the holes in the cowling to the locations indicated by the pieces of paper. Install the wood screws. -- Remove the cowling, and soak the newly created cowling screw holes with thin CA and allow to cure to strengthen the cowling mounts. -- Remove the tape from the canopy hatch and sides of the fuselage and reinstall the cowling. Everything should align properly and the canopy hatch fitting nicely under the cowling. -- -- On the base of the rudder, using a sharp knife open the covering the slot for the tail wheel wire. Add some thick CA to the slot and insert the wire as shown below.

 

-- Insert the rudder into the fuselage, make sure it swings 45 degrees in both directions, and glue the hinges with a couple of drops of thin CA from each side as shown.

-- Slide the tail wheel bracket over the wire and screw the wood screws into place through the bracket as shown below. Make sure that the rudder swings freely. -- Remove the screws to apply thin CA to the screw holes. -- Screw the bracket back into place after the thin CA has cured.

 

 

 

 

 

-- Install the tail wheel onto the wire, making sure the wheel rotates freely tighten the set screw with a 1.5mm hex tool as shown below.

 

 

-- Insert aileron into wing panel making sure to align the end of the aileron with the wing tip. -- Making sure that the aileron can deflect 45 degrees in each direction freely and glue the hinges with a couple of drops of thin CA on each side. NOTE: it is recommended to glue the inside hinge, re-check the aileron motion, and then glue the hinge near the wingtip followed by the hinges in the middle.

 

 

 

-- With a sharp knife, clear the covering over the slot for the control horn in the aileron as shown.

-- Test fit the control horn into the slot. Remove the horn and add a bead of thick CA into the control horn slot. Apply some thick CA to each side of the lower portion of the control horn and insert the horn into the aileron as shown.

-- Install the aileron servo into the wing as shown below. Inside the servo hole there is a piece of string added for convenience to attach your servo wire with tape to help guide the servo wire to the wing root. -- The pushrods for the Yak are assembled as shown below. At the control horn the ball link is screwed onto the threaded end of the pushrod 5-6 turns. With the 2mm screw, washer and nut, the ball link is then bolted to the control horn and tightened fully tight. -- Use a drop of thick CA on the nut to lock it in place. NOTE: the longest pushrod is for the elevator, and the two smaller equal length pushrods are for the ailerons.

-- The pushrod connectors for the servo arms are also shown in the photo above. The hole in the servo arm is enlarged to accept the connector, and making sure there is a washer either side the nut is added although not tightened all the way. The nut should only be made to be a snug fit so that the connector can still rotate. Add a drop of thick CA to the bottom of the nut to secure it in place and allow to cure. -- Use a 1.5mm hex tool to secure the set screw on top to hold the pushrod. -- Repeat this process for the opposite wing. -- Using a sharp knife, open the slot for the pull-pull rudder control horn as shown.

-- Slide the horn through and center it to get an idea as to where it sits, slide out, add thick CA to the center of the horn (make sure to get CA into the holes) on both sides and slide back in making sure it’s centered properly before the glue cures. Once in place, put a few drops of thin CA around the horn on each side.

-- Please examine the following pull-pull diagram closely

-- When attaching the servo connectors to the arm, do not tighten the nut fully, but leave it a bit loose so the connectors can rotate freely. Use a drop of CA glue on the nut to prevent it from loosening in flight. -- Start by attaching the cables to the pull-wire end. Crimp well, preferably by making creases in the crimp tube with sharp pliers or cutters, rather than smashing it completely flat. Apply a drop of thin ca to the completed crimp to prevent it from sliding on the cable.

 

 

-- Mount the rudder servo as shown below. -- Insert the pull-wire ends into the servo connectors on the rudder servo as shown, just barely poking through the servo connectors, and tighten down the set screws with a 1.5mm hex wrench. Note that the cables cross each other once inside the fuselage, making an “X” shape. -- Spend time to find the exact correct length of the pull-pull wires before attaching the pull wire ends at the front. The system provides approximately .25 inch of adjustment on each wire when completed, so your assembly must be accurate. NOTE: it is helpful to tape the rudder in the center position to get the correct length on the pull-pull wires. -- When you are certain your wire length is correct, crimp the wire to the ends and use the adjustor to properly tension the wires as a final adjustment. We want the wires to be snug, without sag, but not springy-tight. NOTE: Proper adjustment of the pull-pull wires is critical. Too-loose wires allow the rudder to flop back and forth in flight, ruining precision flight. Too-tight wires cause the servo to drag and lose power, leading to a lack of rudder authority.

-- In a fashion similar to the ailerons described above, clear the covering over the control horn slot for the elevator with a sharp knife and glue the control horn into place with thick CA. -- With a sharp knife clear the elevator servo hole and mount the elevator servo as shown. Assemble the pushrod and bolt to the elevator control horn. Install the servo connector to link up the servo.

 

 

-- With a sharp knife, remove a panel of covering underneath the fuselage as shown to allow cooling air a place to exit the aircraft.

 

-- Mount your receiver and radio equipment into the fuselage. An example of final setup is shown below. A balsa plate is also provided to glue into the plane where convenient to mount your receiver with velcro or your preferred technique.

 

 

 

 

 

 

 

 

 

 

OPTIONAL ASSEMBLY Side Force Generators Side force generators (SFG) are optional on this airframe and simple to install and remove. -- Locate the small rectangular holes near the tip of the wings and clear the covering with a sharp hobby knife as shown.

 

 

 

 

-- On the ends of the wingtips, clear the covering over the two screw holes as shown.

-- Slide the tabs on the Side Force Generators into the holes above and below the wing, so that the taper of the SFG

leading edge is pointing forward as shown. -- Insert the nylon bolts into the holes and tighten until snug with a flat head screwdriver.

 

 

 

 

 

 

Cowling Detail Another optional feature of this kit is the cowling detail that resembles the radial cooling vanes seen on the full scale Yak-55. Note that the use of the plate does restrict some cooling air entering the cowling to cool the motor, ESC and batteries. So depending on your climate you may need to open just a panel or two for cool climates, or for hot climates it may be best to leave it off the plane for maximum cooling. -- Cut out some cooling air holes from the cowling detail using a pair of scissors or a sharp hobby knife. -- Center the cowling detail plate in the cowling and glue with CA by running a bead of medium or thick CA around the inside edge of the cowling as shown. Allow to fully cure before continued handling of the cowling as the flexing of the cowling can prevent good adhesion.

 

 

SETUP INFORMATION Center of Gravity The recommended Center of Gravity range is 2.75 to 3.25 inches from the leading edge of the wing root. For maiden flight, the plane should ideally have the Center of Gravity at the designer recommended 2.75 inches. After several flights, you can and should adjust to find your perfect, personal CG location.

 

Control throws Low / Precision Rates (in degrees and inches) and Corresponding Exponential

Aileron 15 degrees 20% expo Elevator 10 degrees 20% expo Rudder 20 degrees 30% expo

High / 3D Rates (in degrees and inches) and Corresponding Exponential Aileron 35 degrees 75% expo Elevator 45 degrees or more 75% expo Rudder 45 degrees 75% expo

Note: that Hitec and Futaba radios require NEGATIVE exponential, while JR and Spektrum use POSITIVE exponential. Servo arm length: Most servo arms have multiple locations in which you can install your pushrod adjustors into, giving different effective servo arm lengths. The method to determine the correct hole is as follows: Set your high-rate throws as indicated above using the endpoint adjustment for each channel in your transmitter. If your endpoint adjustment is near maximum (a value of 140-150 on most transmitters) then you are using the correct hole. However, if your endpoint adjustment is much lower, under 125 for example, you may need to use a hole that gives a shorter effective arm length. If your endpoint adjustment for correct high-rate throws is excessively low, you will notice very poor servo performance. To put it simply, use the shortest arm length that still allows proper high rate throws. Once you are certain of the correct arm length, be sure to use thick CA to lock all of your adjustor nuts on all servo arms.

 

Enjoy Your 3DHS Yak55!

Again, if you have any issues, questions, concerns or problems during assembly, please contact our tech

department at: info@3DHobbyShop.com or 1-717-814-5316 10am-4pm Eastern Time, Monday-Thursday. We highly recommend www.RCGroups.com as a good source for RC tips, tricks, and information.