FBRC Sparrow 400

FBRC Sparrow 400 – 2 Channel RC Plane A lightweight, 3D-printable RC plane designed for relaxed flying, simple assembly and affordable electronics! The FBRC Sparrow 400 is a compact, 2-channel RC plane designed to make getting into 3D-printed aircraft as simple and accessible as possible. With a wingspan of just over 400mm, a lightweight printed airframe and a straightforward control system, the Sparrow is designed for casual park flying and enjoying the skies. The design uses electronics salvaged from an inexpensive Z50 2-channel RC plane, keeping costs down and making the project more accessible. Almost all the electronics and propulsion components can be reused, meaning you don't need to buy a complete new set of RC equipment. Link to the donner model: https://www.hawks-work.com/products/hawks-work-2-ch-rc-airplane-rc-plane-ready-to-fly-2-4ghz-remote-control-airplane-easy-to-fly-rc-glider-for-kids-beginners-red - A full build guide and ready-to-use Bambu Studio print profiles are included to help you go from the print bed to the flying field! - Features: • Simple 2-channel controls – throttle and directional control without complicated mixing or additional servos. • Differential thrust steering – left and right turns are controlled by varying the thrust of the two motors. • Gyro-assisted stability – uses the donor aircraft's control board to help keep the plane flying straight. • Lightweight construction – as little as 45g for the printed frame when using PLA Basic and a 0.2mm nozzle. • Removable main wings – convenient for transport, storage and repairs. • Spring-latched canopy – provides quick and easy access to the battery bay. • Accessible power switch – switch the aircraft on and off without dismantling it. • Easy to print – almost no supports required; supports are only needed for the canopy. • Straightforward assembly – just 14 printed parts, with alignment dowels built into the fuselage and wings. • Low-cost electronics – designed around readily available donor components. • Full build guide included – step-by-step assembly instructions to help you build your own Sparrow. • Bambu Studio profiles included – print settings provided for both 0.2mm and 0.4mm nozzle setups. Specifications: Model FBRC Sparrow 400 Wingspan: 403mm Length: 382mm Height: 93mm Channels: 2 Frame weight: (0.2mm nozzle) 45g / (0.4mm nozzle) 67g All-up weight: (0.2mm nozzle) 65g / (0.4mm nozzle) 86g Thrust 30–40g Thrust-to-weight ratio (0.2mm): 0.43:1 Thrust-to-weight ratio (0.4mm): 0.33:1 Centre of gravity (CG): 19–21mm behind the leading edge Motors: 2 × 615 brushed motors Propellers: 2 × 50mm Battery: 1S / 3.7V LiPo Recommended battery capacity: 200–400mAh Reference battery: 360mAh Weights are approximate and depend on print settings, filament and assembly. All-up weight (AUW) includes the completed aircraft and electronics. Printing Information The Sparrow has been designed with practical 3D printing in mind, keeping the number of parts low and minimising the need for post-processing. Using a 0.2mm nozzle is recommended • Filament: PLA Basic • Print profiles: Bambu Studio profiles included for 0.2mm Nozzle (0.4mm nozzle on the way) • Supports: Required for the canopy only • Printed frame weight: Approximately 45g with a 0.2mm nozzle or 67g with a 0.4mm nozzle • Assembly: 14 printed parts The 0.2mm nozzle configuration produces a lighter airframe, which is beneficial for this small aircraft. The 0.4mm nozzle configuration offers an alternative for builders who prefer to print with a more conventional nozzle size. However please note, during testing the 0.4mm, performance was sluggish. BOM / Parts Required The Sparrow is designed around components from the Z50 2-channel RC aircraft. Parts need from donner aircraft: • 2 × 615 brushed motors • 2 × 50mm propellers • Original 2-channel receiver and gyro control board • 1S LiPo battery In addition, your will also need: • 1 x small rubber band • 2 x M1.7x7mm (0r M2x7mm) self-tapping screws • 1 x Pen Spring (Diameter 4mm) Other donor aircraft electronics may also be suitable, but modifications to the motor mounts and component trays may be required. Assembly The Sparrow has been designed to keep assembly as straightforward as possible. The fuselage and wings use alignment dowels to help ensure everything fits together straight, while the removable main wings make transportation and maintenance much easier. With the parts printed and the donor electronics ready, assembly is designed to take approximately 30–45 minutes depending on your experience and preparation. A full build guide is included with the downloadable files, covering the assembly process and installation of the electronics. Flight & Setup The Sparrow uses a simple control system: • Throttle: Increase power to climb and reduce power to descend or glide. • Left and right: Differential thrust from the two motors provides directional control. • Gyro: The donor control board helps stabilise the aircraft and maintain a straight flight path. Before flying, check the centre of gravity is between 19mm and 21mm behind the wing's leading edge, verify that the controls respond correctly, and ensure the battery is secure. The Sparrow is a small, lightweight aircraft designed for park flying, so choose a calm day and a suitable open flying area for initial testing. The recommended thrust and thrust-to-weight figures are design targets and should be verified with your own electronics and setup. Documentation Included: • FBRC Sparrow 400 printable model files • Bambu Studio print profiles for 0.2mm nozzles (0.4mm on the way!) • Full build guide • Designed-in alignment features for easier assembly The models shown in the phots have been printed using a Bambu Lab P2S using a Hardened Steel 0.4mm Noxxle and a stainless Steel 0.2mm Nozzle. the fillament used was: Orange: Basic PLA - Creality Hyper RFID Orange (FF6600) Green: Basic PLA - Creality Hyper RFID Green (00AA3C) Light Green: Bambu Lab Matt PLA - Matte Apple Green (11502 Black: Bambu Lab Matte PLA – Charcoal Black (11101) The FBRC Project The FBRC Sparrow 400 is all about making RC aircraft design, 3D printing and flying more accessible. By combining a compact printed airframe with inexpensive donor electronics, it offers an approachable project for makers who enjoy designing, printing, building and testing their own aircraft. If you build one, I'd love to see your results, modifications and flight videos! Happy printing and happy flying! I am a hobbyist designer and creator with a passion for designing and I love to know how I can improve my designs so any comments or advice on how my Designs, Guides or Print Profiles could be improved are always welcome! Thank you for reading and have fun making!