The Scorpion HKIII-4025 motors follow in the footsteps of the larger HKIII-4035 models which re-wrote the book on power for helicopter models. Replacing the earlier model HK-4025-550, the HKIII-4025-550 motor features a new patented rotor can that provides several benefits. First, it is thicker for more stability at higher speeds, and this also helps to retain more of the magnetic field for higher efficiency. Second, the outer surface of the rotor can features a new spiral rib pattern that increases surface area and helps to move air around the motor for increased cooling and lower operating temperatures.
In addition to the mechanical changes to these motors, changes in metallurgy in the stator assembly and rotor can have increased the overall efficiency. This allows the motor to handle higher currents while developing more torque and more power that will allow your helicopter to perform like never before.
Scorpion HKIII Series Brushless Motors are built from the best materials available, and are designed to provide both quality and performance at an affordable price. Scorpion starts with high quality aluminum alloy parts that are produced on the latest CNC milling machines. These parts are then gold Electro-plated to provide a beautiful, long-lasting finish. The stators are made with 0.2mm lamination's to give maximum efficiency, and minimum Eddy current losses. The stators are epoxy coated to prevent shorts, and are wound with wire that is rated at 180 degrees C (356 F). The magnets used in Scorpion Motors are the highest temperature rating available, making a motor that is virtually impossible to burn up in normal use.
All Scorpion HKIII-4025 series motors come with 4mm male Bullet style connectors already attached, and include a hardware package that contains 3 matching female Bullet connectors for your speed controller with matching heat shrink tubing. For maximum strength, the Scorpion HKIII-4025 series motors feature an 8mm motor shaft that is ground down to a 6mm diameter at the output end to fit standard size pinion gears. Since the HKIII Series motors are primarily designed for Helicopter use, they do not include a prop adapter. If you intend on running a prop on this motor, you will need to purchase a prop adapter for a 6mm shaft.
Scorpion Motors are built to last, and are backed with a 2-Year warranty against defects in materials or workmanship. However, due to the high RPM of these motors, and the fact that we cannot control the installation and setup, the bearings are not covered by the 2-Year warranty, nor is any subsequent damage caused to the motor by a bearing failure. Bearings are a normal wear item, and as such, need to be maintained and changed periodically. For maximum life, make sure that a sufficient gap is left between the pinion and main gear during motor installation to avoid binding, and put a small drop of oil on each bearing every 5-6 flights. It is the responsibility of the pilot to ensure that the bearings are maintained properly.
The Scorpion Motor Bearing Lubrication Kit is now available for maintaining the bearings in your helicopter motor. To view this product, please check out the Bearing Lubrication Kit.
For the best overall combination of quality, performance, and value, use Scorpion Motors in your helicopter!
Included in the box
|Scorpion HKIII-4025-550 Motor Specifications|
| Stator Diameter|| 40.0 mm (1.575 in)|
| Stator Thickness|| 25 mm (0.98 in)|
| Number of Stator Slots|| 12|
| Number of Magnet Poles|| 10|
| Motor Wind|| 6-7 Turn Delta|
| Motor Wire|| 22-Strand 0.29mm|
| Motor Kv Value|| 550 RPM per Volt|
| No Load Current (Io)|| 1.65 Amps @ 10 Volts|
| Motor Resistance (Rm) per Phase|| 0.023 Ohms|
| Maximum Continuous Current|| 65 Amps|
| Max Continuous Power (12-cell Li-Po)|| 2850 Watts|
| Motor Weight|| 354 grams (12.49 oz.)|
| Outside Diameter|| 49.98 mm (1.97 in.)|
| Shaft Diameter|| 5.98 mm (0.24 in.)|
| Motor Body Length|| 54.3 mm (2.14 in.)|
| Overall Shaft Length|| 90.1 mm (3.55 in.)|
| Max LiPo Cell|| 12s|
| Peak Current|| 90 Amps (5 seconds)|
| Peak Continuous Power|| 3900 Watts (5 seconds)|
| Motor Timing|| 5deg|
| PWM Frequency|| 8kHz|
1 x Scorpion HKIII-4025-550kv Motor
3 x Female Connectors
3 x Heat Shrink
4 x M3 Screws
Weight including packaging
View Scorpion HKIII-4025-550KV (6mm) Full Dimension