Futaba S-A300 Standard Digital RC Servo 11kg 0.17s FUT05102732-3

Overview

The Futaba S-A300 Standard Digital Servo PWM/S.BUS2 is a premium coreless digital servo engineered for RC aircraft and other demanding applications where precision control and rapid response are essential. This compact yet powerful servo delivers exceptional performance in a standard-size package, making it an ideal choice for RC enthusiasts across the UK looking to upgrade their control systems or build high-performance RC models. Whether you're piloting RC planes, helicopters, or other RC vehicles that demand smooth, reliable servo operation, the S-A300 combines cutting-edge digital technology with robust metal gearing to provide the control authority you need.

Futaba has been a trusted name in RC radio control since 1962, and the S-A300 represents their commitment to quality and innovation. This servo supports both conventional PWM protocol and Futaba's advanced S.BUS2 digital communication system, offering compatibility with virtually any modern RC radio system. The combination of a coreless motor design and metal gears with bearing support ensures smooth, responsive control whilst maintaining exceptional durability. At just 47 grams, this servo adds minimal weight to your RC model, allowing you to optimise your setup for better flight characteristics and performance.

The S-A300 operates across a voltage range of 4.8V to 7.4V, providing flexibility for different battery configurations. At maximum voltage (7.4V), this servo achieves an impressive 11.0 kgf cm of torque and completes a 60-degree transit in just 0.17 seconds, delivering the speed and strength necessary for responsive control inputs. This makes it particularly suitable for RC aircraft that demand rapid control response, though it performs equally well in other RC applications requiring reliable standard-size servo performance.

Key Features

• Coreless Digital Motor Design — The coreless motor technology eliminates iron losses and provides a lighter, more efficient motor that responds instantly to control inputs, crucial for the precision flying required in modern RC aircraft and other performance-demanding applications.
• Metal Gears with Bearing Support — Unlike plastic gears found in budget servos, the S-A300 features a 2-3 stage metal gear train with bearing support throughout, dramatically reducing wear and extending servo lifespan whilst ensuring smooth, backlash-free operation even under sustained use.
• Dual Protocol Support (PWM and S.BUS2) — This servo accepts both traditional PWM signals and Futaba's S.BUS2 digital protocol, providing maximum compatibility with your existing RC radio systems whether you're running older PWM receivers or the latest S.BUS2 technology.
• Exceptional Speed Performance — With a transit time of just 0.17 seconds per 60 degrees at 7.4V, the S-A300 delivers rapid response that translates directly into more precise control of your RC model, particularly important for aerobatic flying or quick corrective inputs.
• Powerful 11.0 kgf cm Torque — The 11.0 kgf cm torque output (at 7.4V) provides plenty of strength to move control surfaces decisively, preventing the servo from stalling under aerodynamic loads that would bind lesser servos, ensuring reliable control throughout your flying envelope.
• Compact Standard Size — Measuring just 40×20×38.1mm, the S-A300 fits standard servo mounting locations on RC aircraft and other vehicles, simplifying installation and allowing drop-in replacement of existing servos without requiring custom modifications.
• Lightweight at 47 Grams — Weighing only 47 grams, this servo adds minimal weight to your RC model, preserving valuable weight budget for batteries, fuel, fuel cells or other equipment, directly improving flight performance and efficiency.
• Wide Voltage Operating Range — Operating from 4.8V up to 7.4V, the S-A300 adapts to your power system whether you're running NiMH batteries, 2S LiPo packs, or higher voltage configurations, providing flexibility in battery selection.
• 25T Spline Metal Output Shaft — The 25-tooth metal spline shaft with 6mm diameter provides a standard interface for servo horns and arms, ensuring compatibility with a vast array of aftermarket servo horns and control linkages available for RC models across the UK.

Technical Performance

The Futaba S-A300 represents a significant step up from budget servo options, combining several engineering choices that translate directly into superior real-world performance. The coreless motor eliminates the iron core found in conventional designs, reducing motor inertia and allowing faster acceleration of the rotor, which directly improves response time and makes control inputs feel more immediate and precise. The metal gear train consisting of 2-3 stages ensures that torque is delivered smoothly without the binding or dead zones that sometimes plague plastic-geared servos. Bearing support throughout the gear train reduces friction and wear, meaning your servo will maintain consistent performance throughout its service life rather than gradually degrading as internal wear accumulates.

At 7.4V operation (a single lithium polymer cell or series of NiMH batteries), the servo delivers 152.8 ounces-force per inch of torque, which converts to the specified 11.0 kgf cm rating. This torque level proves sufficient for most standard RC aircraft applications, preventing servo stall when encountering aerodynamic forces during manoeuvres or turbulent conditions. The speed specification of 0.17 seconds per 60-degree movement at 7.4V makes this one of the faster standard servos available, enabling crisp, responsive control that's particularly valuable for acrobatic flying or when precision control is paramount. Even at lower 6.0V operation, the servo still delivers respectable performance with 0.19-second transit time and 138.9 ounces-force per inch torque, making it viable for 4-cell NiMH systems or where lower battery voltage is preferred.

The digital circuit design allows the servo to accept both PWM (pulse width modulation) control signals used in conventional RC systems and Futaba's proprietary S.BUS2 protocol, which combines multiple servo signals into a single digital data stream. This flexibility means the S-A300 works seamlessly whether you're upgrading an existing RC system or building a new one. The servo's compact dimensions and light weight make it particularly suitable for aircraft applications where every gram counts and space is limited, though the servo's robust construction and reliable performance make it equally at home in ground-based RC vehicles or other applications.

What's in the Box

• 1x Futaba A-A300 Standard Digital Servo
• Multiple servo horns for different control linkage configurations
• Complete mounting hardware including screws and brackets

Frequently Asked Questions

• What's the difference between the S-A300 and other standard size RC servos available in the UK? — The S-A300 stands out through its coreless motor design and metal gears with bearing support, which together provide faster response, smoother operation, and longer lifespan compared to budget plastic-geared servos. The inclusion of S.BUS2 support alongside traditional PWM also provides greater compatibility with modern RC radio systems than some competitors offer.
• Can I use the S-A300 in a 1S LiPo system? — Whilst the servo's minimum operating voltage is 4.8V (which is near 1S LiPo nominal voltage), Futaba recommends operation at 6.0V or higher for optimal performance and lifespan. A single LiPo cell's voltage drops below 4.8V relatively quickly during discharge, so a 2S LiPo pack (7.4V nominal) is the better choice for reliable operation and full performance.
• Is this servo suitable for RC aircraft beginners? — Yes, the S-A300 makes an excellent choice for RC aircraft builders at any experience level. The servo's reliability, smooth operation, and responsive control make it ideal for learning to fly, whilst its digital design and S.BUS2 compatibility mean it will remain useful even as you progress to more advanced RC aircraft and radio systems.
• What battery configuration should I use with the S-A300? — The servo performs optimally with 2S LiPo batteries providing 7.4V, which delivers maximum torque and speed as specified. Alternatively, you can use 6-cell NiMH packs at 7.2V for slightly reduced but still excellent performance. For weight-conscious applications, 2S LiPo is preferred, whilst for maximum reliability in less weight-critical applications, NiMH is equally viable.
• Does the S-A300 work with my existing RC radio system? — Most likely yes. The servo supports both PWM and S.BUS/S.BUS2 protocols, providing broad compatibility. If your receiver outputs PWM signals (the vast majority do), the servo will work perfectly. If you have a newer S.BUS2 receiver, the servo utilises that protocol for cleaner, more efficient signal transmission.
• How does the coreless motor differ from standard motor designs? — Coreless motors eliminate the iron core typically found at the centre of conventional motors, reducing rotational mass and friction. This design allows the rotor to accelerate and decelerate more quickly, translating into faster servo response times and smoother control feel during flight manoeuvres.
• What does the metal spline shaft provide that plastic wouldn't? — The metal 25-tooth spline shaft resists stripping and wear far better than plastic alternatives, ensuring that servo horns remain securely attached and control linkages don't slip or become loose over time. This reliability is essential in RC aircraft where control surface slippage could create a safety hazard.
• Can I use this servo in an RC boat or car? — Absolutely. Whilst the S-A300 is engineered for aircraft, its performance characteristics make it equally suitable for any RC vehicle requiring a standard-size servo. The compact size, light weight, and responsive control work well in steering and throttle control for ground and water-based RC models.

Why Buy from RC Model Shop?

RC Model Shop is a trusted UK RC retailer and authorised dealer for all the brands we stock, including Traxxas, ARRMA, Losi, FTX, Hobbywing, Spektrum and more. Based in Walsall, we have a physical store where customers are welcome to come in, view products and purchase in store. Whether you are a seasoned competitor, a weekend basher, or just discovering the world of RC for the first time, our team of experienced RC enthusiasts is here to help you find the perfect setup and provide ongoing support. Order the Futaba S-A300 Standard Digital Servo PWM/S.BUS2 11kg 0.17s 4.8V - 7.4V FUT05102732-3 today with confidence, knowing you are buying from an authorised retailer with genuine products, expert knowledge and a commitment to customer satisfaction. Shop online or visit us in Walsall — we look forward to helping you get the most out of your RC experience.