Overview
The ARRMA Input Shaft Cup, Safe-D (Z-ARA311144) is a premium replacement drivetrain component designed specifically for high-performance ARRMA RC vehicles. This spare part is engineered to deliver reliability and durability when you need it most, whether you're a competitive racer pushing your RC car to the limit or a weekend basher enjoying off-road thrills across the UK. The Input Shaft Cup is a critical component in your vehicle's drivetrain, and choosing a genuine ARRMA replacement ensures optimal compatibility and performance with your existing setup.
If you own an ARRMA 1/8 KRATON 6S V6 4X4 BLX Speed Monster Truck, 1/7 LIMITLESS 8S AVC 4X4 RTR BLX Street Speed, 1/8 NOTORIOUS 6S V6 4X4 BLX Stunt Truck, or any compatible Safe-D model, this Input Shaft Cup is an essential spare to keep in your RC toolkit. Whether you're replacing a worn component after intensive use or building up a backup drivetrain, this part delivers the quality and precision you expect from ARRMA's engineering. For RC enthusiasts across the UK looking for reliable drivetrain spares, this is a trusted choice from one of the industry's most recognised manufacturers.
The Safe-D design represents ARRMA's commitment to keeping your vehicle running even when the unexpected happens. This innovative feature ensures that your RC car maintains drive capability in the event of a minor setback, making it an excellent choice for bashers and racers alike who demand reliability from their equipment.
Key Features
- Machined Steel Construction — This Input Shaft Cup is machined from strong and durable steel material, providing exceptional strength and resistance to the stresses and impacts that come with aggressive RC driving. Steel's superior durability means this component will withstand the demands of high-performance off-road racing and casual bashing alike, offering excellent value for money over extended use.
- ARRMA Safe-D Design — The innovative Safe-D design keeps the input gear and drive cup key together as a unified assembly, ensuring that your vehicle maintains drive capability in the critical event that the attachment screw loosens during operation. This redundant safety feature gives you peace of mind and keeps you in action even if fasteners work free under extreme conditions.
- Precise Screw Threads — The Input Shaft Cup features precisely machined screw threads that guarantee a safe and secure fit for the supplied M4 x 6mm securing set screw. This precision engineering means you can trust the fastening system to remain solid and reliable through intense driving sessions without risk of accidental loosening.
- Genuine ARRMA Spare Part — As an official ARRMA component, this Input Shaft Cup delivers the exact fit and performance characteristics your ARRMA vehicle was engineered to use. Using genuine spares ensures optimal drivetrain geometry and performance, eliminating compatibility concerns that can arise with third-party alternatives.
Technical Performance
The ARRMA Input Shaft Cup represents precision engineering at its finest. Manufactured from high-grade steel using precision machining processes, this component is built to handle the extreme forces generated by brushless motors and high-voltage battery systems in modern RC vehicles. The material selection and machining tolerances ensure that the Input Shaft Cup maintains its structural integrity even under the intense stresses of 6S and 8S LiPo powered ARRMA vehicles. The Safe-D design integration demonstrates ARRMA's commitment to reliability, with the input gear and drive cup key functioning as a single assembly that prevents drivetrain failure even if the primary fastening screw becomes loose. The precisely threaded bore accommodates the included M4 x 6mm set screw with minimal tolerance, ensuring a rock-solid connection that won't shift or slip during acceleration, cornering, or impact events. This level of engineering is essential for maintaining optimal power transmission from motor to differential in high-performance 4WD vehicles like the KRATON 6S V6, LIMITLESS 8S, and NOTORIOUS 6S V6 platforms.
What's in the Box
- 1 x Input Shaft Cup (Safe-D)
- 1 x Set Screw M4 x 6mm
What You Need to Complete
- ARA311145 - Input Shaft Cup Sleeve (2pcs) — required to complete the input shaft assembly
- Suitable Safe-D compatible input gear matched to your main differential gear
Frequently Asked Questions
- Is the ARRMA Input Shaft Cup Safe-D suitable for my ARRMA RC vehicle? — This Input Shaft Cup is compatible with several ARRMA models including the 1/8 KRATON 6S V6 4X4 BLX Speed Monster Truck (all colour variants), 1/7 LIMITLESS 8S AVC 4X4 RTR BLX Street Speed, and 1/8 NOTORIOUS 6S V6 4X4 BLX Stunt Truck. Check your vehicle's model number against the compatibility list to confirm this part is correct for your RC car. If you're unsure, our team at RC Model Shop can help identify the right part for your specific model.
- What does the Safe-D design actually do for my RC car? — The Safe-D design keeps your input gear and drive cup key together as a single assembly, ensuring your vehicle maintains drive capability even if the attachment screw loosens during operation. This redundant safety feature means you won't lose all drivetrain function due to a single fastener working loose, giving you extra reliability during competitive racing or casual bashing sessions.
- What additional parts do I need to install this Input Shaft Cup? — To complete your input shaft assembly, you'll need the ARA311145 Input Shaft Cup Sleeve (which comes as 2 pieces) and a suitable Safe-D compatible input gear that matches your main differential gear ratio. These items work together with the Input Shaft Cup to form a complete, functioning assembly.
- Why should I choose the genuine ARRMA part instead of aftermarket alternatives? — Using genuine ARRMA spares ensures perfect compatibility, optimal performance characteristics, and the same quality standards that went into your original vehicle. The Safe-D design and precision machining are engineered specifically for ARRMA's drivetrain geometry, giving you confidence that the part will fit perfectly and function reliably. Genuine parts also maintain your vehicle's warranty coverage and resale value.
- Is this suitable for beginners? — This is a replacement spare part rather than a complete vehicle or standalone product, so it's intended for owners who already have an ARRMA RC vehicle and need to replace a worn or damaged component. If you're new to RC cars, we recommend starting with a complete Ready to Run RC vehicle kit and consulting our expert team about maintenance and spare parts.
- Can I upgrade my current setup with this part? — The Input Shaft Cup is a direct replacement component for compatible ARRMA models. It's not designed as an upgrade but rather as a genuine replacement for your existing part. If you're looking to enhance your vehicle's performance, our team at RC Model Shop can recommend appropriate upgrades and complementary parts for your specific model.
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 ARRMA Input Shaft Cup, Safe-D Z-ARA311144 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.
