Hosim F28-CS02 Helical Main Drive Differential Gear Upgrade Manual

1. Introduction

This manual provides detailed instructions for the installation, maintenance, and troubleshooting of the Hosim F28-CS02 Helical Main Drive Differential Gear. This chrome steel upgrade accessory is designed to enhance the performance and durability of compatible 1:8 and 1:10 scale Hosim RC cars. Please read these instructions carefully before proceeding with installation or maintenance.

2. Product Overview & Features

The Hosim F28-CS02 is a high-quality helical main drive gear designed as an upgrade for your RC vehicle's differential system. Its key features include:

• Part Number: F28-CS02
• Material: Upgraded to durable chrome steel for enhanced longevity.
• Performance: Helical gear design provides less vibration, reduced noise, and smoother rotation compared to standard gears.
• Strength: Significantly stronger construction, tested for resilience against damage.
• Quantity: 1 unit per package.

Figure 2.1: Hosim F28-CS02 Helical Main Drive Differential Gear.

Figure 2.2: Top-down view of the helical gear, showcasing its intricate design for optimal performance.

3. Compatibility

This helical main drive gear (F28-CS02) is compatible with the following Hosim 1:8 and 1:10 scale RC car models:

• Hosim X07
• Hosim X07W
• Hosim X08
• Hosim X15W
• Hosim X17
• Hosim X25
• Hosim X27

Important Note: When upgrading to this helical main drive gear, it is highly recommended to also replace the differential (Hosim F28-CS01) for optimal performance and compatibility.

4. Installation Guide

Follow these steps carefully to install your new helical main drive differential gear. Refer to the accompanying video for visual guidance.

4.1. Tools Required

• Hex Drivers: 2.5mm, 2.0mm, 1.5mm
• Heat Gun or Lighter (for loosening old screw adhesive)
• Screw Lock Adhesive (Red - high-temperature, high-viscosity for pinion; Blue - low-intensity, low-viscosity for motor mount)
• Small Scissors (for paper strip)
• A4 Paper Strip (for gear mesh adjustment)

4.2. Step-by-Step Installation

1. Disconnect Motor Cables: Carefully disconnect the motor's three-phase cables from the Electronic Speed Controller (ESC).
2. Remove ESC: Gently move the ESC out of the way to access the motor mount area.
3. Remove Side Guard: Using a 1.5mm hex driver, remove the four screws securing the protective side guard. Once screws are removed, the side guard can be detached.
4. Remove Motor Dust Cover: Use a 2.0mm hex driver to remove the single screw holding the motor dust cover. Remove the cover.
5. Remove Motor: Using a 2.5mm hex driver, remove the two screws from the motor mount plate that secure the motor. The motor can now be removed.
6. Remove Heat Sink: Detach the heat sink from the motor.
7. Remove Old Pinion Gear:
   • Locate the grub screw on the pinion gear. Use a 1.5mm hex driver.
   • If the screw is too tight due to old adhesive, gently apply heat with a heat gun or lighter to the grub screw area to loosen the adhesive.
   • Once loosened, remove the grub screw and slide the pinion gear off the motor shaft.
8. Install New Pinion Gear:
   • Place the new F28-CS02 helical main drive gear onto the motor shaft.
   • Apply a small amount of high-temperature, high-viscosity red screw lock adhesive to the grub screw. This is crucial for securing the pinion gear due to high speeds and temperatures.
   • Tighten the grub screw clockwise to secure the pinion gear in place.
9. Reinstall Motor: Replace the motor onto the motor mount plate. Do not fully tighten the screws yet.
10. Set Gear Mesh: Proper gear mesh is vital for smooth operation and preventing premature wear.
    • Cut a small strip of standard A4 paper.
    • Insert the paper strip between the new pinion gear and the spur gear.
    • Position the motor to the closest possible position to the spur gear, ensuring the paper strip is held firmly but can still be pulled out without tearing. This creates a gap equal to the paper's thickness.
    • Apply low-intensity, low-viscosity blue screw lock adhesive to the motor mount screws. This allows for easier future removal if needed.
    • Secure the motor plate by tightening the two screws with a 2.5mm hex driver.
11. Reinstall Components:
    • Reinstall the motor dust cover.
    • Reinstall the protective side guard.
    • Reinstall the ESC to its original position.
    • Reconnect the motor's three cables to the ESC.
12. Test Gear Mesh and Rotation: Rotate the tires by hand and listen for smoothness. There should be no binding or excessive play. Power on the RC car and remote control, then check the throttle and reverse rotation to confirm smooth and correct operation.

Figure 4.1: The helical main drive gear correctly installed within the differential housing, ready for operation.

Figure 4.2: Visual representation of the helical gear meshing with the spur gear, illustrating the smooth contact points.

5. Maintenance

Regular maintenance of your differential gear is essential for prolonging its lifespan and ensuring consistent performance.

• Inspection: Periodically inspect the helical main drive gear and the spur gear for any signs of wear, damage, or foreign debris.
• Cleaning: Clean any dirt, dust, or grime from the gears using a soft brush or compressed air.
• Lubrication: Apply a small amount of appropriate RC gear grease to the meshing surfaces of the helical and spur gears to reduce friction and wear. Avoid over-lubrication, which can attract dirt.
• Gear Mesh Check: Re-check the gear mesh periodically, especially after heavy use or impacts, to ensure it remains optimal.

6. Troubleshooting

If you encounter issues after installing the F28-CS02 gear, consider the following:

• Noisy Gears: This often indicates incorrect gear mesh. Re-adjust the gear mesh using the paper strip method described in the installation section. Also, check for proper lubrication and ensure no foreign objects are lodged between the gears.
• Binding or Sticking Gears: This can be caused by overly tight gear mesh, bent motor shaft, or damaged gears. Inspect all components and re-adjust the mesh.
• Stripped Gears: If gears are stripped, they need to be replaced. Common causes include incorrect gear mesh, excessive power, or impacts. Ensure the recommended differential (F28-CS01) is also used with this helical gear.
• Motor Overheating: An improperly set gear mesh can cause the motor to work harder, leading to overheating. Verify the gear mesh is correct and ensure the motor's cooling fan (if applicable) is functioning properly.

7. Specifications

8. Warranty & Support

For warranty information, technical support, or replacement parts, please contact Hosim customer service through their official website or the retailer where the product was purchased. Keep your proof of purchase for warranty claims.