Key Features
- Performance linear tail servos designed specifically for use with AS3X ultra micro heli's
- Performance linear long throw servo designed specifically for use with AS3X ultra micro heli's
- 13.5 mm servo throw
- Compact footprint
- JST-SHR Connector
- Brand: Spektrum
- Model Number: P-SPMSH2040T / SPMSH2040T
- Servo Type: Linear tail servo for ultra-micro aircraft
- Application: Helicopter, AS3X ultra-micro aircraft
- Weight: 2.9 grams (0.10 oz)
- Length: 23 mm (0.9 inches)
- Width: 18 mm (0.7 inches)
- Height: 10 mm (0.4 inches)
- Servo Throw: 13.5 mm linear
- Motor Type: Brushed DC motor
- Gear Type: Nylon
- Bearing Type: Single ball bearing
- Connector Type: JST-SHR 1.0 mm
- Wire Length: 115 mm (4.52 inches)
- Input Voltage Range: 3.2V - 4.2V
- Maximum Servo Speed: 0.065 seconds per 60 degrees at 4.2V
- Maximum Servo Torque: 9.6 oz/in at 4.2V
- Programmable: Yes
- Water-Resistant: No
- Servo Size Category: Ultra Micro
- Servo Configuration: Analog
Overview
The Spektrum SPM 2.9g Linear Tail Servo is a precision-engineered micro servo specifically designed for ultra-micro RC helicopters and aircraft equipped with AS3X stabilisation technology. At just 2.9 grams, this is one of the lightest and most compact servo solutions available for the RC hobby market in the UK, making it an essential component for builders and pilots who demand minimal weight without compromising on performance or reliability. Whether you're flying ultra-micro helis or compact fixed-wing aircraft, this servo delivers the responsive control and durability you need for stable, predictable flight characteristics.
Spektrum is a globally recognised brand trusted by RC enthusiasts, racers and professional pilots alike. Their servo technology is renowned for precision engineering, consistent performance and compatibility with the latest digital flight control systems. This linear tail servo represents the pinnacle of micro servo design, combining ultra-lightweight construction with genuine performance specifications that make a real difference in the air. If you're serious about your RC aircraft hobby in the UK, this servo should be on your shopping list.
The SPM 2.9g Linear Tail Servo is perfect for anyone upgrading their micro helicopter setup, building a custom ultra-micro aircraft, or replacing a worn servo in an existing platform. With its compact footprint, high-quality brushed motor, nylon gears and JST-SHR connector, this servo integrates seamlessly into modern AS3X systems whilst delivering the throw distance and response time needed for precise flight control. RC Model Shop stocks this genuine Spektrum product as an authorised UK retailer.
Key Features
- Linear Long Throw Design — This servo features a 13.5 mm servo throw, providing substantially more control authority than standard micro servos of similar size. The linear actuation mechanism ensures predictable, smooth control response across the full range of motion, which is critical for precise tail control on ultra-micro helicopters.
- Ultra-Lightweight Construction — At just 2.9 grams, this servo minimises weight whilst maintaining structural integrity and performance. Every gram saved on servo weight translates directly to improved flight performance, better battery efficiency and easier aircraft handling characteristics.
- Compact Footprint — With dimensions of 23 mm length, 18 mm width and just 10 mm height, this servo fits into the tightest spaces on modern ultra-micro aircraft and AS3X compatible helicopter platforms. The compact design makes it ideal for weight-conscious builds where installation space is limited.
- JST-SHR Connector — The industry-standard JST-SHR 1.0 mm connector ensures compatibility with modern Spektrum receivers and flight control systems. This connector type is lightweight, secure and widely used throughout the ultra-micro RC community in the UK and worldwide.
- Programmable Servo — Unlike fixed-function servos, this model is fully programmable, allowing you to customise travel range, centre point and response characteristics using compatible Spektrum transmitters and software. This flexibility means you can optimise servo behaviour for your specific aircraft setup.
- High-Quality Brushed Motor — Featuring a brushed DC motor design, this servo provides reliable, responsive control with minimal latency. The motor is tuned specifically for the lightweight demands of ultra-micro platforms, delivering consistent torque across battery voltage ranges.
- Nylon Gear Construction — The servo uses nylon gears that offer an excellent balance between weight, cost and durability. Nylon gears are proven in micro servo applications and provide smooth, quiet operation without the brittleness of plastic gears or the weight penalty of metal alternatives.
- Single Bearing Support — This servo uses a single ball bearing in the output shaft mounting, providing smooth rotation and minimal friction. The bearing design is optimised for ultra-micro applications where weight is critical but smooth operation is essential.
- Wide Operating Voltage Range — Operating from 3.2V to 4.2V, this servo is compatible with standard 1S LiPo battery systems used on most ultra-micro helicopters and aircraft. The wide voltage tolerance ensures consistent performance even as battery voltage sags slightly during flight.
Technical Performance
The SPM 2.9g Linear Tail Servo delivers impressive performance metrics for an ultra-micro servo platform. Operating across a 3.2V to 4.2V input voltage range, the servo achieves a maximum speed of 0.065 seconds per 60 degrees of rotation at 4.2V, which translates to responsive, snappy control inputs ideal for stabilising tail movement on AS3X equipped helicopters. Maximum torque output reaches 9.6 ounces per inch at 4.2V, sufficient for authority over the tail rotor authority required on ultra-micro heli platforms. The servo's brushed motor provides consistent, predictable power delivery without the noise or complexity of brushless alternatives. Construction quality reflects Spektrum's reputation for precision engineering: nylon gears ensure durability at ultra-micro scale, whilst the single ball bearing output shaft minimises friction and extends service life. The compact 23 mm × 18 mm × 10 mm physical envelope and 2.9 g weight make this servo genuinely suitable for weight-critical applications where every gram matters. The 115 mm (4.52 inch) lead wire with JST-SHR connector arrives ready for installation into modern Spektrum receiver systems. Whether you're upgrading a worn servo, building a custom ultra-micro helicopter, or replacing a damaged unit in an existing AS3X platform, the SPM 2.9g delivers the technical credentials and build quality expected from Spektrum's servo range in the RC hobby market.
What's in the Box
- SPM 2.9g Linear Tail Servo with JST-SHR connector
- Pre-assembled servo ready for installation
Frequently Asked Questions
- Is the Spektrum 2.9g Linear Servo suitable for AS3X equipped ultra-micro helicopters? — Yes, this servo is specifically designed for use with AS3X ultra-micro aircraft and helicopters. The linear design, throw distance and response characteristics are optimised for AS3X flight control system compatibility, making it an ideal choice for pilots running Spektrum AS3X stabilisation technology.
- What voltage battery system does this servo require? — The servo operates across 3.2V to 4.2V, which means it runs on standard 1S LiPo battery systems (1-cell LiPo) commonly used on ultra-micro helicopters and aircraft. Always ensure your battery voltage stays within the specified range for optimal performance and longevity.
- How heavy is this servo and why does weight matter on ultra-micro aircraft? — The servo weighs just 2.9 grams, making it one of the lightest servo solutions available. On ultra-micro helicopters and aircraft, weight directly impacts flight performance, battery efficiency, handling characteristics and overall flight time. Saving grams on servo weight translates to measurable improvements in aircraft responsiveness and endurance.
- Can I programme this servo with my Spektrum transmitter? — Yes, the SPM 2.9g Linear Servo is fully programmable with compatible Spektrum transmitters and software. You can customise travel range, centre point, rate and other servo parameters to match your specific aircraft setup and flying preferences.
- What is the servo throw distance and why is 13.5 mm significant? — The servo provides 13.5 mm of linear throw, which is substantial for a micro servo of this scale. Longer throw distances provide greater control authority over tail movement, allowing more precise and responsive helicopter control. This is crucial for stabilising tail rotor input on AS3X systems.
- What connector type does this servo use and is it standard? — The servo uses a JST-SHR 1.0 mm connector, which is the industry standard for modern Spektrum receivers and flight control systems. This connector type is lightweight, secure and universally compatible with contemporary ultra-micro RC platforms in the UK hobby market.
- Is this servo water-resistant or weatherproof? — No, the SPM 2.9g Linear Servo is not water-resistant. It should be protected from moisture and kept dry during storage and transport. If flying in wet conditions or near water, ensure the servo remains dry to avoid electrical damage or corrosion.
- How does this servo compare to standard fixed-weight servos? — This linear servo delivers significantly more throw distance (13.5 mm) than many standard micro servos, whilst weighing only 2.9 grams. The programmable nature, JST-SHR connector compatibility and AS3X optimisation make it specifically superior for modern ultra-micro helicopter and aircraft applications versus generic alternatives.
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 SPM 2.9g Linear Tail Servo P-SPMSH2040T 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.
We want to make sure your delivery goes smoothly, so here are some important details about our service:
- For orders above £120, we offer delivery to most mainland UK addresses. For orders under £120, we can still deliver to Northern Ireland and the outlying isles, as long as the item can be sent by Royal Mail, weighs less than 30kg, and fits within 61cm × 46cm × 46cm. Some highland and remote areas may carry an extra delivery charge as couriers often apply surcharges in these locations. If you live in one of these areas, feel free to contact us before ordering so we can confirm the delivery options and costs for you.
- Most of our products include delivery in the price. If your order is under £90, a small delivery fee will apply but do not worry this will always be clearly shown at checkout before you complete your purchase.
- Depending on what you choose at checkout, your order will usually be delivered either the next working day or within 2 working days. For next day delivery please place your order before 2:00pm. Orders are dispatched Monday to Friday only. Some items may take a little longer and if that is the case we will always show the expected delivery time on the product page.
- If your order includes items with different dispatch times we will normally wait and send everything together once all items are in stock. If one of the items is going to take a while we will give you the choice either wait for everything to arrive or let us send the available items now and deliver the rest later. It is up to you.
- We use trusted delivery partners to make sure your order gets to you safely and on time. We use DPD for next working day deliveries and Royal Mail for the 2 day option.
- As soon as your order is on its way we will send you a tracking number by email. If you provide your mobile number at checkout we will also send delivery updates straight to your phone so you can keep an eye on progress.
- If a product is marked as "Dispatched within 3 working days" delivery usually takes around 3 to 5 working days from when your order is placed.
- For customers in Inverness and other parts of the Scottish Highlands deliveries can take up to 2 working days even if you select next day delivery as couriers do not currently offer a guaranteed next day service to those areas.
