• F3A contra drive system with RED 4025HS 500KV motor and 1:4 gear assembly, front view on white
  • Contra drive motor and gearbox assembly lying on side, carbon plate and white gear visible
  • Side profile of contra drive unit showing motor, white gear ring, and red output shaft
  • Front face view of contra drive showing red hub, blue fasteners, and carbon mounting plate
  • Angled view of contra drive showing red spinner hub, carbon bracing, and gear housing
  • Package contents: motor with mount plate, toothed belt, and four blue standoffs/spacers
  • Retail box set for F3A contra drive, packaging with model and motor specs printed
  • F3A contra drive packaging box, 'Designed for F3A Contra Drive' text on front
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F3A Contra Drive System RED 4025HS 500KV Motor, 1:4 Gear Ratio, F3A Pattern Contra Drive

F3A Contra Drive System RED 4025HS 500KV Motor, 1:4 Gear Ratio, F3A Pattern Contra Drive

Gemfan

$1,053.50 USD
$1,053.50 USD
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Overview

The F3A Contra Drive System is a contra-rotating propeller drive system for use in F3A pattern competition, built around the RED 4025HS 500KV motor and a 1:4 gear ratio.

F3A contra drive system exploded view with RED 4025HS 500KV motor, 1:4 gearbox, shafts and bearings

Key Features

  • Titanium alloy motor shaft and middle shaft for reduced weight.
  • Plastic gear with hardened surface.
  • Gear material uses oily plastic for wear resistance and quieter operation.
  • Tested with this motor; stated to save electricity.

Specifications

Product name F3A Contra Drive System: RED 4025HS 500KV
Motor KV 500KV
Gear ratio 1:4

Performance (Prop: Falcon F21X20R21X20)

Motor Battery (mAh) Speed Current Draw (A)
Original P19: 2800-3500 Horizontal: 85-90 Static: 75
F19: 3500-4000 Vertical: 75 Max Horizontal: 63
Vertical: 68
     
 
Align 700MX P19: 2800-3500 Horizontal: 85-90 Static: 75
F19: 3500-4000 Vertical: 75 Max Horizontal: 63
Vertical: 68
     
 

Selecting the Right Gear Ratio (Gearset: 1:4)

Props Gearset Downline Braking Horizontal Speed Vertical Pulling Power
22x18 Rear, 22x18 Front 1:4 +++ + +++
22x20 Rear, 22x20 Front ++ ++ ++
22x22 Rear, 22x22 Front + +++ ++

Component Reference (Exploded View List)

No. Part name
1 Front fairing rear pad
2 Front pad
3 Fairing back cover
4 Inner shaft
5 Outer shaft
6 Outer shaft bearing
7 Bearing housing
8 Synchronous wheel (small)
9 Small gear
10 Foreboard
11 Synchronous wheel (large)
12 Big gear
13 Back plate
14 Connecting column
15 Rear bearing
16 Motor

Applications

  • F3A pattern competition aircraft requiring a contra-rotating propeller drive system

For setup and compatibility questions, contact support@rcdrone.top or visit https://rcdrone.top/.

Details

Exploded parts diagram with numbered component list for the contra-rotating prop drive gearset, shafts, plates and hardware

An exploded parts layout helps confirm the shafts, gears, bearings, and covers before installation or ordering spares.

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