Overview
The SPM Firma 3660-3100Kv 4-Pole Sensorless Brushless Motor is a high-performance electric motor designed for RC enthusiasts who demand reliability, power and precision in their brushless RC vehicles. This compact yet powerful motor delivers impressive output and is engineered to provide consistent performance across a wide range of RC car applications. Whether you're building a competition-grade RC buggy, upgrading an existing 1/10 scale RC car, or seeking a versatile brushless motor option for your RC collection, the Firma 3660 represents Spektrum's commitment to quality engineering and proven performance in the UK RC hobby market.
Built by Spektrum, a recognised leader in RC electronics and motors, this sensorless brushless motor combines advanced motor design with practical usability. The 3100Kv rating strikes an excellent balance between acceleration and top speed potential, making it suitable for varied driving conditions and skill levels. If you're new to brushless RC cars or upgrading from a brushed setup, this motor offers the reliability and performance that serious RC hobbyists expect from a trusted brand.
The Firma 3660-3100Kv is particularly valued in the RC car community for its robust 4-pole construction, which provides smooth power delivery and efficient energy conversion. Its sensorless operation simplifies installation and reduces overall system complexity, whilst maintaining the performance advantages that brushless technology is renowned for. This motor represents excellent value for anyone seeking to upgrade their RC car setup or build a new ready-to-run or competition RC platform.
Key Features
- 3100Kv Rating — The Kv rating determines the motor's speed characteristics, and 3100Kv offers a versatile middle ground that provides strong torque whilst maintaining reasonable top-end speed, making this motor adaptable to various RC driving styles and vehicle configurations across the UK RC hobby.
- 4-Pole Motor Construction — The four-pole design delivers more consistent torque delivery and smoother acceleration than simpler motor designs, resulting in better handling characteristics and more predictable performance for drivers of all skill levels in RC car racing and bashing applications.
- Sensorless Brushless Technology — Operating without position sensors simplifies the motor design and reduces complexity, allowing for straightforward installation into compatible ESC systems while maintaining all the efficiency benefits of brushless motors that make them the preferred choice for modern RC vehicles.
- 5mm Shaft Diameter — The standard 5mm shaft is compatible with a wide range of RC car pinions and drive systems, ensuring easy integration into most 1/10 scale RC car platforms available in the UK market without requiring additional adapters or modifications.
- Compact 36mm Diameter Housing — The 3660 size designation refers to the 36mm outer diameter, which is compact enough for efficient cooling and fits into space-constrained RC vehicle chassis whilst providing sufficient power for demanding applications.
- High Power Output — Delivering 1150 watts on a 3S LiPo battery, this motor provides genuine performance suitable for competitive racing, high-speed bashing and various RC car disciplines, ensuring your RC investment delivers thrilling driving experiences.
- Standard 4mm Bullet Connectors — The industry-standard connector type ensures broad compatibility with most brushless ESC systems and battery packs available to UK RC hobbyists, simplifying component selection and reducing compatibility concerns.
Technical Performance
The Firma 3660-3100Kv represents excellent engineering that prioritises reliability alongside performance. With a compact outer diameter of just 36mm and a length of 60mm, this motor is designed to fit into most modern RC car chassis configurations without requiring extensive modifications. The 5mm shaft diameter is the standard across 1/10 scale RC vehicles, ensuring straightforward compatibility with pinions, drive systems and transmission components from all major RC brands. The motor's brushless construction eliminates carbon brushes entirely, which means reduced maintenance, longer operational life, and superior efficiency compared to traditional brushed motors commonly found in older RC car designs. The 3100Kv rating provides an intelligent balance between low-end torque and top-end speed potential—faster than crawler-oriented motors but more controlled than ultra-high-speed options. When powered by a 3S LiPo battery system (the most common battery voltage for RC cars in the UK), the Firma 3660 generates 1150 watts of continuous power output, translating into responsive acceleration and sustained performance across demanding driving scenarios. The 4-pole construction ensures commutation is smooth and predictable, reducing cogging and vibration that can affect handling precision in competitive RC racing environments. Spektrum's engineering means you're purchasing a motor that has been thoroughly tested and proven in real-world RC applications, offering the reliability that UK RC enthusiasts depend upon.
What's in the Box
- SPM Firma 3660-3100Kv 4-Pole Sensorless Brushless Motor with 5mm shaft
What You Need to Complete
- Brushless ESC (Electronic Speed Controller) compatible with sensorless brushless motors—ensure your ESC is rated for the power level and battery voltage you intend to use
- LiPo Battery (3S recommended based on 1150W output specification at 3S voltage)
- Battery Charger suitable for charging LiPo batteries
- RC Car Chassis with compatible motor mounting plate
- Motor pinion gear matching your desired final drive ratio
- Radio Control transmitter and receiver compatible with your RC vehicle
Frequently Asked Questions
- What battery voltage does the Firma 3660-3100Kv motor use? — The motor is specified to deliver 1150 watts of power on a 3S LiPo battery (11.1 volts nominal). Whilst sensorless brushless motors can operate on other voltages, 3S LiPo is the recommended system for this motor to achieve optimal performance and protect the motor and ESC from overpowering.
- Is the Firma 3660-3100Kv suitable for beginners? — Yes, this motor is excellent for beginners transitioning to brushless RC cars. The 3100Kv rating provides manageable acceleration and speed rather than extreme top-end capability, making it easier to control. The sensorless design simplifies installation, and compatibility with standard 5mm shafts means integration into most beginner-friendly RC platforms is straightforward. If you're purchasing your first brushless RC car or upgrading from a brushed motor, this represents a sensible choice that won't overwhelm new drivers.
- What is the difference between this 3100Kv motor and other Spektrum Firma motors? — The primary difference lies in Kv rating, which affects speed and torque characteristics. The Firma 3660-3100Kv offers a mid-range Kv suitable for balanced performance, whilst higher Kv motors (such as the Firma 3650-4000Kv or Firma 3300Kv variants) provide either higher top-end speed or lower speed with more torque respectively. Choose based on your driving style: lower Kv for more control and torque, higher Kv for speed-focused racing.
- How does sensorless brushless technology differ from sensored brushless? — Sensorless brushless motors lack position sensors and determine rotor position through back-EMF voltage, resulting in a simpler motor with fewer internal components and lower cost. Sensored motors include hall-effect sensors that provide precise rotor position information. For most RC car applications including bashing and racing, sensorless brushless motors like the Firma 3660 perform excellently and are the standard choice across the UK RC hobby.
- What ESC do I need for this motor? — You'll need a brushless ESC rated for sensorless operation and designed for your intended power level. Given the 1150W output at 3S, an ESC with at least 30-50 amps continuous current rating is recommended. Spektrum manufactures compatible ESCs, and most modern brushless ESCs from reputable manufacturers will work with this motor—ensure your selection specifically supports sensorless brushless motors.
- Can I use this motor in any RC car? — The Firma 3660-3100Kv is designed for 1/10 scale RC cars and compatible with any platform that accepts a standard 5mm shaft motor and has appropriate mounting provisions. The 36mm diameter is standard for 1/10 scale applications. Always verify that your specific RC chassis can physically accommodate a motor this size and has compatible motor mounting hardware before purchasing.
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 Firma 3660-3100Kv 4-Pole Sensorless Brushless Motor:5mmshaft M-SPMX-1081 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.
