Servo Arm Set 25T 28T Double Head Round Steering Gear for RC Helicopter

Key Features

• 25T Horn Gear Spline — The set includes a 25T horn gear spline option for matching standard servo horns.
• Multiple Arm Sizes — The set covers a range of arm sizes, including 30*8mm, 21*5.8mm, 31*5.8mm and 56*8mm arms.
• Screw Assortment — The kit includes M2.5*14 and M3*5 screws for attaching the arms.
• Plastic Construction — The arms are made of plastic, with a PC plastic type noted for the set.

Product Specifications

• Material: Plastic
• Plastic Type: PC
• Horn Gear Spline: 25T and 28T
• Age Range: 14+y
• Power: No battery
• Remote Control Peripherals/Devices: Servos

What It Is / How It Works

This servo arm set is a kit of replacement and spare steering gear arms for RC helicopter servos. The set is described as a double head round type servo arm part, with 25T and 28T horn gear spline options, a range of arm sizes, and matching screws. The About details note it is suitable for Emax JX SPT DSPOWER HD 20kg and 30kg servos, along with standard steering engines from other brands.

Who It's For / Use Cases

Hobbyists who fly and maintain RC helicopters often keep spare servo arms on hand when a steering linkage needs replacing or a different arm length is needed for a build. Builders who swap horns or test different linkage geometry tend to look for a range of arm sizes and matching screws in one kit, which is the type of assortment this set provides.

How to Use / Care

1. Use these servo arm parts as servo arm accessories for RC helicopter steering gear, the use named in the product title.

How to Choose

Start with the spline count on the servo horn you already have, then choose the 25T or 28T option that matches it. Next, look at the arm length you need for your linkage, since this set includes many lengths from short arms around 10.6*3mm to longer arms such as 56*8mm. Finally, check that the screw sizes, such as M2.5*14 and M3*5, suit the holes on your servo and arm. Matching these three points helps you pick the right parts for the job.

Frequently Asked Questions

Does this set include batteries?
No. The set does not include batteries, and its power entry is No battery. It is made for servo arm use in RC helicopters, so plan to power your servo through your existing receiver setup.

Which horn gear spline sizes are offered?
The set offers 25T and 28T horn gear spline options. Check the spline count on your servo horn before you choose the matching option.

What arm sizes are in the set?
The set includes arms from 10.6*3mm up to 56*8mm, including 30*8mm, 21*5.8mm, 31*5.8mm, 56*8mm, 24.3*6mm, 21.4*6mm, 26*5.2mm, 38.6*6mm, 45*6mm, 19.7*4.2mm, 32*4.2mm, 34.5*4.2mm, 17.5*4mm, 28.8*4mm, 16*3.3mm, 17*3.3mm and 27*3.3mm.

Which screws come with the set?
The kit includes M2.5*14 screws (4 pieces) and M3*5 screws (1 piece), along with M2*8, M2*5, M1.7*4, M2*7.6 and M1.7*4.5 screws in the arm assortment. The screws are sized for attaching the arms to the servo.

What material is the set made from?
The arms are made from plastic, with a PC plastic type noted. The set also carries a CE certification mark.