Servo Tray Assembly Installation

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Tools Required Jewelry SIzed Phillips and Flat Screw Drivers Phillips #2 Driver Wire Frame Landing Gear 1/16" drill bit and hobby drill Servo Tray Compatibility for Metal Servos If you are reusing a T-Hawk servo tray and will be installing CS-919MG metal gear servos, make sure it is the servo tray version with the taller standoffs as shown.
Remove the old Servo Tray Assembly (1) Disconnect the pushrod tail connections and remove the six servo tray screws on the underside of the fuselage. Open the canopy cover and hold it open by latching the canopy rubber band to the front wing post. Slide the servo tray assembly forward as far as the pushrods will allow. This works well for T-Hawk and SkySeeker GT. For Predator push the assembly back and pull through the fuselage opening below the wing. Now it will be easy to remove the servo arm connections and then the servos.
Install the new Servo Tray Assembly (2) If you are installing the CS-919MG metal gear servos, you will need to trim the servo tray as shown.
(3) The new servo arms should be trimmed leaving only 4 holes as shown. Note that you may have received them trimmed already. The new servo arms must be placed on the replacement servos when they are centered. Connect the replacement servos into the proper Rudder & Elevator receiver ports. Note the Rudder servo is over the landing gear slot molded in the servo tray which will be the forward servo position. For safety, remove the propeller. Power up the transmitter and then the aircraft. Center both the rudder and elevator trims on the transmitter. The servos are now zeroed with the center trim position on your radio. Now install the new servo arms at right angles to the servo body as shown. Note the arm must directed to the right when oriented as shown. Set both servos like this.
(4) Insert the wire frame landing gear through the housing slot. This will stabilize the fuselage during the process and will also be used to fix the position of the new servo tray while drilling.
(5) Insert the shorter push rod (elevator push rod) into the tail boom forward slot. Push through as far as possible with the V-bend pointed UP and over the slot.
(6) Feed the elevator push rod end through the open end of the servo tray and then up through the opening where the elevator servo will mount. (rear stand-off set) Make the push rod connection to the servo arm 4th hole position (3rd hole for SkySeeker GT). Note the pushrod Z-bend must enter from the underside of the servo arm. Slide the servo arm past the first bend and position the servo over the rear standoffs and fasten with screws.
(7) Insert the longer push rod (rudder push rod) into the tail boom aft slot. Feed it through the servo tray end and out through the opening where the rudder servo will mount. (forward stand-off set) Make the push rod connection to the servo arm 4th hole position (3rd hole for SkySeeker GT). Note the pushrod Z-bend must enter from the topside of the servo arm. Slide the servo arm past the first bend and position the servo over the forward standoffs and fasten with screws.
(8) Place the Servo Tray Assembly onto the housing floor with landing gear slot facing forward and over the landing gear wire protrusion. Hold the landing gear with one hand, and the servo tray in the other, press the two together until the servo tray is fully seated on the fuselage floor and the landing gear is fully inserted.
(9) Drill the 2 forward 1/16" pilot holes through the fuselage & servo tray base and insert screws, don't over tighten. Apply pressure on the backs of the servos as needed to make sure the screws bite into the pilot holes.
(10) Perform a visual check - you should see about 1/8" of the screw emerging through the servo tray floor.
(11) Then drill and fasten the 2 mid points, and lastly the 2 aft points. This progression of 2 at a time minimizes hole offsets that occur between the servo tray and fuselage if all 6 are done at once.
Final Test (12) Connect the servo cables to the receiver. The forward servo plugs into CH1-Rudder and the aft servo into CH2-Elevator. Power up the transmitter, then the aircraft. Moving the stick to the right should pull the rudder stick into the tail boom. Moving the stick down should pull the elevator stick into the tail boom. Move the stick diagonally back and forth. Confirm the push rods move smoothly and there are no clicking sounds that usually indicate binding or interference.