The Scorpion HK-4025 motors have been developed for the newer 550 to 600 class electric helicopters that are now coming onto the market. These motors are designed to provide all the power that you can use, while still maintaining excellent efficiency and cool running characteristics.

Scorpion HK 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 anodized to provide a beautiful, long-lasting finish. The stators are made with 0.2mm laminations 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 N-50EH style, which are rated for operation at 200 degrees C (392 F), making a motor that is virtually impossible to burn up in normal use.

All Scorpion HK-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 shink tubing. For maximum strength, the Scorpion HK-4025 series motors feature an 8mm motor shaft that is ground down to a 5mm diameter at the output end to fit standard size pinion gears. Since the HK series motors are primarily designed for Helicopter and Ducted Fan 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 5mm 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!

Specifications

Stator Diameter ............................ 40.0 mm (1.575 in)
Stator Thickness ........................... 25.0 mm (0.975 in)
No. of Stator Arms ................................................ 12
No. of Magnet Poles ................................................ 8
Motor Wind ........................................... 10 Turn Delta
Motor Wire ..................... 24-Strand 0.25mm (30 AWG)
Motor Kv ............................................. 740 RPM / Volt
No-Load Current (Io) ................. 1.33 Amps @ 8.4 volts
Motor Resistance (Rm) ............................. 0.017 Ohms
Max Continuous Current ............................... 70 Amps
Max Continuous Power .............................. 2450 Watts
Weight ...................................... 326 Grams (11.50 oz)
Outside Diameter .......................... 48.9 mm (1.925 in)
Shaft Diameter ............................. 4.98 mm (0.196 in)
Body Length ................................. 51.4 mm (2.024 in)
Overall Shaft Length ...................... 77.0 mm (3.031 in)