Introduction
This manual provides essential information for the proper setup, operation, and maintenance of your FUTABA S-U300 or S-U400 Universal Standard Digital Servo. These servos are designed for use in various RC models, including airplanes, helicopters, and cars, offering precise control and reliable performance. Please read this manual thoroughly before using your servo to ensure safe and optimal operation.
Product Overview
The FUTABA S-U300 and S-U400 are universal digital servos featuring all-resin gears and S.BUS compatibility. They are designed for different voltage requirements and torque/speed characteristics to suit a range of RC applications.
Figure 1: FUTABA S-U300 and S-U400 Servo Packaging with Key Dimensions.
Figure 2: FUTABA S-U300 and S-U400 Servos with Accessories.
Setup and Installation
- Power Connection: Before initial use, ensure the servo is powered on (within the specified voltage range) and allowed to return to its neutral position.
- S-U300: Requires 4.8V to 6.0V DC.
- S-U400: Requires 6.6V to 7.4V DC (High Voltage).
Caution: Do not use dry cell batteries as a power source for the servo. Ensure the power supply matches the servo's voltage requirements.
- Mounting: Securely mount the servo within your RC model's frame using appropriate hardware. Ensure there is no binding or obstruction to the servo's movement.
- Linkage Setup: After the model's frame is assembled, set the maximum stroke of the servo. This stroke must be consistent with the physical travel limits of the control surface or mechanism it operates to prevent damage to the servo or model.
- S.BUS Compatibility: These servos support the S.BUS method for simplified wiring and setup with compatible receivers. Refer to your receiver's manual for S.BUS connection details.
Figure 3: S-U300 Servo with Included Accessories for Installation.
Figure 4: S-U400 Servo with Included Accessories for Installation.
Operating Instructions
FUTABA digital servos provide precise and responsive control. Once installed and calibrated, they will respond to commands from your RC transmitter via the receiver.
- Ensure your transmitter and receiver are properly bound and configured according to their respective manuals.
- Always perform a range check before operating your model to ensure reliable control.
- Avoid applying excessive force to the servo horn, as this can damage the internal gears or motor.
- Monitor servo temperature during operation, especially in demanding applications. Overheating can lead to reduced performance and premature failure.
Maintenance
- Cleaning: Keep the servo clean and free from dirt, dust, and moisture. Use a soft, dry cloth for cleaning.
- Inspection: Regularly inspect the servo case for cracks or damage, and check the servo wires for fraying or loose connections.
- Gear Inspection: Periodically check the servo gears for wear. While these servos feature durable resin gears, heavy use or crashes can cause wear.
- Storage: Store servos in a dry, cool environment away from direct sunlight and extreme temperatures.
Troubleshooting
- Servo Not Responding:
- Check power supply: Ensure the servo is receiving the correct voltage (4.8-6.0V for S-U300, 6.6-7.4V for S-U400).
- Verify connections: Ensure the servo is correctly plugged into the receiver.
- Check transmitter/receiver: Confirm that the RC system is powered on and functioning correctly.
- Erratic Movement or Jittering:
- Interference: Check for sources of electrical interference near the servo or receiver.
- Power fluctuations: Ensure a stable power supply.
- Damaged gears: Inspect gears for signs of wear or damage.
- Weak or Slow Response:
- Low voltage: Ensure the power supply is adequate and fully charged.
- Binding: Check for mechanical binding in the linkage system that might be overloading the servo.
Specifications
FUTABA S-U300 Universal Standard Digital Servo
Figure 5: S-U300 Servo and its Specifications.
| Feature | Detail |
|---|---|
| Type | Universal Standard Digital Servo |
| Application | Airplanes (Standard Servo for Air Use) |
| Gear Type | All Resin Gear |
| Communication | S.BUS Method |
| Speed (6.0V) | 0.19 sec/60° |
| Speed (4.8V) | 0.23 sec/60° |
| Torque (6.0V) | 4.1 kgf·cm |
| Torque (4.8V) | 3.2 kgf·cm |
| Dimensions | 40.4 × 19.8 × 36.0 mm |
| Weight | 36 g |
| Power Supply | 4.8V ~ 6.0V |
FUTABA S-U400 Universal Standard Digital Servo
Figure 6: S-U400 Servo and its Specifications.
| Feature | Detail |
|---|---|
| Type | Universal Standard Digital Servo |
| Application | Airplanes, Helicopters, Cars (High Voltage Servo) |
| Gear Type | All Resin Gear |
| Communication | S.BUS Method |
| Speed (7.4V) | 0.13 sec/60° |
| Speed (6.6V) | 0.14 sec/60° |
| Torque (7.4V) | 7.9 kgf·cm |
| Torque (6.6V) | 7.1 kgf·cm |
| Dimensions | 40.0 × 20.0 × 38.1 mm |
| Weight | 39 g |
User Tips
- Quantity Clarification: The product is typically sold as a single servo unit. If you require multiple servos, please ensure you adjust your order quantity accordingly.
- Voltage Matching: Always double-check that your power source voltage matches the specific requirements of your S-U300 (4.8-6.0V) or S-U400 (6.6-7.4V) servo to prevent damage.
- Linkage Freedom: Ensure all linkages connected to the servo move freely without any binding. Binding can cause the servo to draw excessive current, leading to overheating and premature failure.
- S.BUS Advantage: If your RC system supports S.BUS, utilize it for a cleaner wiring setup and potentially easier configuration of multiple servos.
Warranty and Support
For any technical assistance, troubleshooting beyond this manual, or warranty inquiries, please contact the seller or authorized Futaba service center. Keep your purchase receipt as proof of purchase.
