Overview
The Futaba HPS-A704 Low Profile Brushless Servo is a premium, high-performance servo specifically engineered for precision F3A aerobatic aircraft. This is a specialist component designed for serious RC aeroplane enthusiasts who demand the absolute best in control response, reliability and performance. Whether you're flying competition F3A patterns or pushing the boundaries of precision aerobatic flight, the HPS-A704 delivers the speed, torque and consistency needed to execute crisp, confident manoeuvres with absolute precision. This brushless servo represents the cutting edge of RC servo technology and is recognised as an essential upgrade for dedicated F3A pilots across the UK and Ireland.
Built by Futaba, a leader in RC radio control since 1962, the HPS-A704 combines decades of engineering expertise with modern brushless motor technology. The servo features a custom high-speed brushless motor paired with robust metal final gears, all housed in a lightweight plastic case optimised for low-profile installation. Supporting PWM, S.BUS and S.BUS2 protocols, this servo integrates seamlessly with modern high-voltage receiver systems and is programmable via PC using the optional CIU-2 or CIU-3 USB adapter. At just 48 grams, the HPS-A704 keeps your airframe light whilst delivering exceptional torque and lightning-fast response times.
If you're serious about F3A flying and want a servo that combines reliability, speed and precision in one compact package, the Futaba HPS-A704 is the benchmark choice. RC Model Shop stocks this servo in the UK and can help you find the perfect setup for your next build.
Key Features
- Brushless Motor Technology — The HPS-A704 uses a custom high-speed brushless motor which delivers superior efficiency, cooler running temperatures and longer operational life compared to traditional brushed motors, making it ideal for extended flying sessions.
- Ultra-Fast Response Time — With a transit time of just 0.06 seconds per 60 degrees at 7.4V (or 0.07 seconds at 6.6V), this servo offers blistering-fast actuation that translates to crisp, immediate control input response for precision aerobatic manoeuvres.
- Exceptional Torque Output — Maximum torque reaches 14.0 kgf·cm (194.4 ozf·in) at 7.4V, providing the power needed to maintain control authority even during aggressive aerobatic sequences and high-G manoeuvres.
- Low Profile Design — Measuring just 40.5 x 21 x 26.9mm and weighing only 48 grams, the HPS-A704 fits into compact low-profile servo bays typical of modern F3A aircraft, minimising weight and drag whilst maintaining full control performance.
- Metal Gear Construction — The final stage gear is manufactured from durable metal, providing exceptional strength and longevity under the demanding stresses of competitive aerobatic flying, whilst the upper, middle and bottom case components are reinforced plastic.
- High-Voltage Compatible — Rated for 6.0–7.4V operation with an extended operating range of 4.8–8.4V, the HPS-A704 is fully compatible with modern LiPo battery systems and high-voltage receiver setups, maximising power and performance.
- Multiple Protocol Support — Full compatibility with PWM, S.BUS and S.BUS2 command protocols ensures seamless integration with virtually any modern RC receiver system, providing flexibility and future-proofing for your setup.
- Programmable Performance — The servo can be connected to your PC using the CIU-2 or CIU-3 USB adapter (sold separately) to fine-tune performance parameters and optimise the servo for your specific flying style and aircraft requirements.
- Professional-Grade Reliability — Built to Futaba's exacting standards with metal spline connection (25T, Ø6mm), this servo delivers the consistency and precision that competitive pilots demand from their equipment.
Technical Performance
The Futaba HPS-A704 represents the pinnacle of RC servo engineering for F3A applications. At the heart of this servo is a custom high-speed brushless motor that delivers exceptional efficiency and longevity. The motor's brushless design eliminates brush wear, reduces electrical noise and provides smoother, more consistent power delivery compared to conventional brushed designs. The servo achieves a remarkable 0.06 second transit time per 60 degrees when powered at 7.4V, making it one of the fastest servos available for precision aircraft control. Even at the more conservative 6.6V operating point, the servo still delivers an impressive 0.07 second response time. Torque output scales with voltage: at 6.6V the servo produces 12.5 kgf·cm (173.6 ozf·in) of torque, whilst at full 7.4V operation it reaches a peak of 14.0 kgf·cm (194.4 ozf·in). This voltage-dependent performance means pilots can extract maximum output when needed for aggressive manoeuvres, or dial back voltage if running cooler temperatures become beneficial. The metal final-stage gear is engineered to withstand the cyclic loading and shock loads inherent in aerobatic flight. The combination of plastic case construction (upper, middle and bottom) with strategically applied metal where strength matters most keeps weight to just 48 grams—critical for maintaining the optimum weight and balance of competitive F3A airframes. Operating voltage flexibility is important: the servo is rated for 6.0–7.4V operation but tolerates 4.8–8.4V across its operating range, providing headroom for voltage sag during demanding manoeuvres. The 25-tooth spline (Ø6mm) provides a proven standard connection to horn and linkage hardware. Important note: this servo requires a suitable power supply and does not have built-in BEC (Battery Elimination Circuit) functionality, meaning you must provide power through a dedicated servo battery or high-current receiver battery system—do not attempt to power this servo with dry batteries or attempt to use it without proper power management.
What's in the Box
- 1x Futaba HPS-A704 Low Profile Brushless Servo
- Servo horns (multiple options)
- Mounting hardware (screws and fixings)
What You Need to Complete
- Suitable servo battery or high-current LiPo battery (4.8–7.4V) with proper battery management
- S.BUS2 compatible receiver or receiver with PWM outputs
- Modern RC transmitter compatible with your receiver (S.BUS2, S.BUS or PWM capable)
- RC aeroplane airframe suitable for F3A flying
- CIU-2 or CIU-3 USB adapter if you wish to programme servo parameters via PC (sold separately)
Frequently Asked Questions
- Is the Futaba HPS-A704 suitable for beginners to RC flying? — This servo is specifically designed for experienced F3A pilots and precision aerobatic flyers, not beginners. It is a specialist, high-performance component best suited to those with established RC flying experience. Beginners should consider starting with more robust, forgiving servos before upgrading to precision-focused models like the HPS-A704.
- What voltage should I run the HPS-A704 at for best performance? — The servo is rated for 6.0–7.4V operation, with the fastest response times (0.06 seconds) and highest torque (14.0 kgf·cm) achieved at 7.4V. Running at 6.6V yields slightly slower response (0.07 seconds) but may be preferable in certain flying conditions. The servo tolerates 4.8–8.4V overall, but performance outside the rated 6.0–7.4V window is not guaranteed.
- Can I use the HPS-A704 with PWM, S.BUS or S.BUS2 receivers? — Yes, absolutely. The HPS-A704 supports all three command protocols: PWM, S.BUS and S.BUS2. This makes it compatible with a wide range of modern receivers from Futaba and other manufacturers, providing excellent future-proofing.
- Does this servo include a battery and BEC? — No. The HPS-A704 does not include a built-in BEC (Battery Elimination Circuit) and does not come with a battery. You must provide power to the servo via a dedicated servo battery or high-current receiver battery system operating at 6.0–7.4V. Do not attempt to power this servo with dry batteries.
- How can I programme the HPS-A704? — The servo can be connected to a PC using the Futaba CIU-2 or CIU-3 USB adapter (sold separately). This allows you to fine-tune servo parameters and optimise performance to suit your aircraft and flying style.
- What is the difference between the HPS-A704 and standard servos? — The HPS-A704 is specifically engineered for F3A precision aerobatic flying. Key advantages include its brushless motor (higher efficiency, longer life), extremely fast response time (0.06 seconds), high torque output (14.0 kgf·cm), low weight (48g), metal final gears for durability, and support for modern S.BUS2 protocol. Standard servos typically offer slower response, lower torque or heavier construction.
- Is the HPS-A704 waterproof? — No, this servo is not waterproof. It is designed for F3A aerobatic flying and should not be exposed to water, moisture or harsh weather conditions.
- What is the difference between 6.6V and 7.4V operation? — At 6.6V the servo delivers 0.07 sec/60° speed and 12.5 kgf·cm torque. At 7.4V it achieves 0.06 sec/60° speed and 14.0 kgf·cm torque. Running at higher voltage provides faster response and more power, whilst lower voltage may offer slightly cooler operation and extended servo lifespan.
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 HPS-A704 Low Profile Brushless Servo PWM/S.BUS2 14.0kg 0.06s 4.8V - 7.4V FUT05102724-3 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.
- Brand: Futaba
- Model: HPS-A704
- Part Number: FUT05102724-3
- Product Type: Low Profile Brushless Servo
- Servo Size: Low Profile
- Colour: Black
- Case Material: Plastic (upper, middle, bottom), with metal final-stage gear
- Final Gear Material: Metal
- Motor Type: Brushless (custom high-speed HPS motor)
- Motor Design: Custom high-speed brushless motor
- Spline Type: 25T (Ø6mm)
- Dimensions (L x W x H): 40.5 x 21 x 26.9mm (1.59 x 0.83 x 1.06 inches)
- Weight: 48 grams (1.69 oz)
- Shipping Weight: 0.10 kg (0.22 lbs)
- Max Torque at 7.4V: 14.0 kgf·cm (194.4 ozf·in)
- Max Torque at 6.6V: 12.5 kgf·cm (173.6 ozf·in)
- Speed at 7.4V: 0.06 sec/60°
- Speed at 6.6V: 0.07 sec/60°
- Rated Voltage: DC 6.0V - 7.4V
- Operating Voltage: DC 4.8V - 8.4V
- Command Protocol: PWM, S.BUS, S.BUS2
- Control Circuit: Digital
- Power Supply: Requires dedicated servo battery or high-current receiver battery system
- BEC: No built-in BEC
- Programmable: Yes (via CIU-2 or CIU-3 USB adapter, sold separately)
- Application: F3A precision aerobatic aircraft
- Contents: 1x HPS-A704 Low Profile Brushless Servo, Horns, Mounting Hardware
- Age Recommendation: 14+
- Important Note: NO DRY BATTERY OR BEC USE
Product Description of Futaba FUT05102724-3 HPS-A704 brushless servo with S.Bus2
The Futaba FUT05102724-3 HPS-A704 brushless servo with S.Bus2 is a precision-engineered low profile servo designed specifically for F3A class competition aircraft. With a lightning-fast response time of 0.06 seconds per 60° and a torque output of 14.0kgf.cm at 7.4V, this servo delivers the speed and authority required for high-precision aerobatic maneuvers. The Futaba FUT05102724-3 low profile servo 14kg 0.06s features a custom high-speed brushless motor, metal gears, and a lightweight plastic case—balancing performance with weight efficiency for optimal airframe integration. Fully programmable and compatible with both PWM and S.Bus2 systems, it offers advanced configurability via CIU-3 for pilots who demand tailored control responses.
Key features of the Futaba FUT05102724-3 HPS-A704 brushless servo
- High-speed brushless motor – engineered for rapid actuation and minimal latency
- Low profile design – ideal for wing-mounted installations in F3A aircraft
- Torque output – 14.0kgf.cm at 7.4V for confident control of precision surfaces
- Response time – 0.06 sec/60° at 7.4V for crisp, accurate maneuver execution
- Metal gear train – ensures durability under repetitive high-speed cycles
- 25T spline – compatible with Futaba-standard servo horns and linkages
- Plastic case – lightweight housing optimized for aerobatic airframes
Why is the Futaba FUT05102724-3 programmable servo for F3A aircraft ideal for competitive flying?
The Futaba FUT05102724-3 programmable servo for F3A aircraft is purpose-built for competitive aerobatics, where precision and responsiveness are non-negotiable. Its low profile form factor allows for flush wing installations, reducing drag and improving control geometry. With programmable parameters accessible via CIU-3, pilots can fine-tune servo behavior to match their flight style and aircraft setup. Whether executing slow rolls or snap maneuvers, this servo delivers the accuracy and speed needed to stay ahead in competition.
How does the Futaba HPS-A704 servo with 25T spline and CIU-3 compatibility enhance setup flexibility?
Setup flexibility is key in aerobatic aircraft, and the Futaba HPS-A704 servo with 25T spline and CIU-3 compatibility offers just that. The 25T spline ensures secure linkage with Futaba-standard horns, while CIU-3 support enables PC-based programming for advanced configuration. This allows pilots to adjust endpoints, speed curves, and signal response to suit specific control surfaces and flight routines. The result is a servo that adapts to your aircraft—not the other way around.
What makes the Futaba FUT05102724-3 with metal gears and plastic case ideal for weight-sensitive builds?
Weight management is critical in F3A aircraft, and the Futaba FUT05102724-3 with metal gears and plastic case strikes the perfect balance. The metal gear train provides mechanical resilience, while the plastic housing keeps overall weight to a minimum. This combination ensures reliable performance without compromising the aircraft’s weight distribution or agility. It’s a smart choice for pilots who need strength without excess mass.
Is the Futaba low profile servo for precision aerobatics and HV setups suitable for advanced control systems?
Absolutely. The Futaba low profile servo for precision aerobatics and HV setups is compatible with both PWM and S.Bus2 protocols, making it suitable for traditional receivers and advanced digital systems. Its high-voltage rating ensures consistent torque and speed across a wide operating range, while its programmable interface allows for granular control adjustments. Whether you're flying with a basic transmitter or a fully integrated telemetry system, this servo fits right in.
For aerobatic pilots seeking a lightweight, high-speed servo with advanced programmability and competition-grade performance, the affordable Futaba HPS-A704 with 0.06s speed and 14kg torque is a top-tier solution. Buy Futaba FUT05102724-3 servo with mounting hardware and horns today.
Technical Specifications of Futaba FUT05102724-3 HPS-A704 brushless servo with S.Bus2
Brand, Model and Product Type
- Brand: Futaba
- Model: FUT05102724-3
- Product Type: Futaba FUT05102724-3 HPS-A704 brushless servo with S.Bus2, Futaba FUT05102724-3 low profile servo 14kg 0.06s, Futaba FUT05102724-3 programmable servo for F3A aircraft, Futaba FUT05102724-3 with metal gears and plastic case, Futaba HPS-A704 servo with 25T spline and CIU-3 compatibility
- Product Color: Black
Dimensions
- Product Length: 4.1 cm – compact footprint for wing-mounted installations
- Product Width: 2.1 cm – streamlined for low-profile servo bays
- Product Height: 2.7 cm – optimized for flush mounting in F3A aircraft
- Product Weight: 48 g – lightweight for precision aerobatic builds
- Shipping Weight: 0.10 kg – includes packaging and mounting accessories
Performance Specifications
- Torque at 7.4V: 14.0 kgf.cm – delivers confident control for precision surfaces
- Torque at 6.6V: 12.5 kgf.cm – maintains reliable output under moderate voltage
- Speed at 7.4V: 0.06 sec/60° – ultra-fast actuation for crisp maneuvering
- Speed at 6.6V: 0.07 sec/60° – consistent responsiveness across voltage range
Motor and Signal Control
- Motor Type: Custom high-speed brushless – ensures rapid, efficient operation
- Signal Compatibility: PWM and S.Bus2 – supports both conventional and digital control systems
- PC Connectivity: Compatible with CIU-2 / CIU-3 USB adapter – enables advanced programming and configuration
Construction and Materials
- Gear Type: Metal – built for durability under high-speed cyclic loads
- Bearings: Dual ball bearings – enhances mechanical efficiency and reduces wear
- Spline Count: 25T – compatible with Futaba-standard servo horns
- Case Material: Plastic (upper, middle, bottom) – lightweight housing optimized for aerobatic airframes
Voltage and Power Requirements
- Rated Voltage: DC 6.0V – 7.4V – optimized for high-voltage F3A systems
- Operating Voltage: DC 4.8V – 8.4V – supports a broad range of regulated power sources
- Battery Compatibility: Dry batteries and BEC systems not supported – use regulated LiPo or dedicated power modules only
Application and Use Case
- Servo Type: Low Profile – ideal for F3A aircraft and precision aerobatic control surfaces
- Use Case: Aileron, elevator, and rudder control – engineered for speed and accuracy
- Recommended Aircraft: F3A competition planes and aerobatic platforms
What’s in the Box
- 1 × Futaba HPS-A704 Low Profile Brushless Servo
- Servo horns
- Mounting hardware
What You Require
- Compatible Futaba transmitter with S.Bus2 support
- Power source within 4.8V to 8.4V range
- CIU-2 or CIU-3 USB adapter for PC programming (sold separately)
Sold Separately
- Futaba transmitter with programmable servo settings
- CIU-2 / CIU-3 USB adapter
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