A sudden blade strike or hard landing on your YuXiang F112S AH-1 Cobra RC Helicopter often forces high impact torque through the swashplate linkages, stripping the delicate splines on the 4.3g digital servo arms or bending the ball linkage studs. Stripped or cracked plastic servo horns cause uncommanded swashplate tilting, sluggish collective pitch response, and uncontrollable flight drift that can ruin the advanced GPS stabilization. Replacing damaged servo arms with mismatched third-party horns often fails due to incorrect hole positioning or spline pitch mismatches on the micro servo gear shaft. This official YuXiang F112S Servo Arm Set solves all swashplate connection issues. Precision-engineered for 4.3g digital metal-gear servos, this kit includes heavy-duty molded servo arms, corrosion-resistant SUS303 stainless steel ball studs, and brass gear mounting screws to completely restore crisp, rock-solid swashplate geometry. Ships worldwide.
Product Highlights
Factory-Matched Spline Dimensions: Engineered specifically for 4.3g metal digital servos to provide a snug, non-slip mesh on the output shaft.
Corrosion-Resistant SUS303 Ball Studs: Features three 3.175mm stainless steel linkage ball studs that resist wear and ensure smooth movement inside swashplate linkage rods.
High-Torque Brass Spline Screws: Includes specialized brass gear screws that clamp the arms firmly to the servo output shaft without stripping internal threads.
Complete 3-Servo Refresh Pack: Contains 3x Servo Arms, 3x Stainless Steel Ball Studs (3.175mm diameter), and 3x Brass Gear Screws—enough to replace all cyclic pitch servo linkages on the helicopter.
Attaching Ball Linkage Studs: Thread the SUS303 stainless steel ball studs into the designated mounting holes on each servo arm and tighten securely; do not over-torque to prevent plastic stress cracks.
Setting Mechanical Servo Neutral: Power on the helicopter with the flight battery and receiver active (transmitter throttle stick at 50% neutral pitch) to ensure all three cyclic servos center themselves before installing the new arms.
Pressing Arms and Securing Screws: Push the new YuXiang F112S Servo Arm Set horns onto the servo output gear shafts as close to a horizontal 90-degree angle as possible, then fasten firmly using the included brass screws.
Pre-Flight Swashplate Leveling Inspection: Reattach the pushrods to the 3.175mm ball studs and move the transmitter sticks to verify that the swashplate travels smoothly and remains level across the entire pitch range.
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