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  Item found in the following categories;
> Electric Motors > Heli Motors
> Electric Motors > Scorpion Motors
> Electric Motors > Outrunners by size > 45 to 50mm


Scorpion HK-4025-550KV Brushless Outrunner Motor (Perfect for .50 size helicopter)

Scorpion HK-4025-550KV Brushless Outrunner Motor (Perfect for .50 size helicopter)
Scorpion HK-4025-550KV Brushless Outrunner Motor (Perfect for .50 size helicopter)

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.


Stator Diameter: 40 mm(1.56 in)
Stator Thickness: 25 mm(0.98 in)
No. of Stator Arms: 12
Magnet Poles: 8
Motor Wind: 14 Turn Delta
Motor Wire: 18-Strand 0.29mm
Motor Kv: 550KV RPM/Volt
No-Load Current (IO/10v): 0.9 Amps
Motor Resistance (RM): 0.035 Ohms
Max Continuous Current: 65 Amps
Max Continuous Power: 2850 Watts
Weight: 326 Grams (11.5 oz)
Outside Diameter: 48.9 mm (1.9 in)
Shaft Diameter: 4.98 mm (0.19 in)
Body Length: 51.5mm (2.01 in)
Overall Shaft Length: 83.7 mm (3.30 in)
Max Lipo Cell: 12s
Motor Timing: 5deg
Drive Frequency: 8kHz

Included in the Box
1 x Scorpion HK-4025-550KV Motor
3 x Female Connectors
3 x Heat Shrink
4 x M3 Screws

PRODUCT ID: S4025550

Kv(rpm/v) 550
Weight (g) 326
Max Current(A) 65
Resistance(mh) 0
Max Voltage(V) 44
Power(W) 2850
Shaft A (mm) 5
Length B (mm) 52
Diameter C (mm) 49
Can Length (mm) 30
Total Length E (mm) 84
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 Customer rated
Total of 3 discussions.
Garry  1 points - 2/18/2016
My shaft is 6mm it is a HK-4025-550KV_6
Bazzwano  8 points - 6/18/2015
5mm or 6mm shaft? Anyone know for sure? Thx
Garry  1 points - 1/5/2012
Plan to mount this in a hobby king high. Performance 120 mm EDF . Any idea on ESC? 10s. 19,800 rpm. Thinking 120Amp. dlux.
 dante 7 points
Either a Castle hv120 or a Hobbywing hv120, would be the safest. I use hobbywing on all my heli's and they preform better and are far easier to setup that Castle. IMO.
 dante 7 points
Not to mention rarely if ever have you heard of a hobbywing catching on fire.
 Garry 1 points
Thanks dante
Customer Reviews
Overall Rating
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I have this scorpion motor with a turnigy K-Force 120A in my raptor 50 converted to electric, more than 20 flights very good motor, using 2 lipo batteries, 6s 4000 20c and 5s 4000 20c, main gear 86, 9 teeth pinion, 550kv scorpion motor

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Overall Rating
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It is very good motor. The description contains an error. In the description the shaft 5mm, really shaft 6mm is specified.

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Porque lo teneis tan caro?
En Helipross esta a 110$. Incluso en España cuesta 115€.
Que ocurre?

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