Scorpion HK-4025-550 (5mm Shaft) [HK-4025-550]
Optional accessories: Check Related products
Introduction to Scorpion Motors
The Scorpion HK-4025 motors have been developed for the 550 to 600 class electric helicopters and the HK-4025-550KV motor is suitable for the glow to electric conversation of 50 size helicopter. 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 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 shrink 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.
For the best overall combination of quality, performance, and value, use Scorpion Motors in your helicopter!
No. of Stator Arms
No. of Stator Poles
No-Load Current (Io)
Motor Resistance (Rm)
Max Continuous Current
Max Continuous Power
Overall Shaft Length
Max Lipo Cell
|40 mm (1.56 in)
25 mm (0.98in)
14 Turn Delta
18-Stand 0.29 mm
550KV RPM / Volt
0.9 Amps @ 10v
326 Grams (11.50 oz)
48.9 mm (1.9 in)
4.98 mm (0.19 in)
51.5 mm (2.01 in)
83.7 mm (3.30 in))
Included in the Box
1 x Scorpion HK-4025-550KV 5mm Shaft
Weight including packaging
View Scorpion HK-4025-550KV (5mm Shaft) Full Dimension
* Please note that photographs may not accurately represent the number of items per package, size, color or features of a product.