FMS Futura 64mm EDF Speed Nozzle (Performance Accessory)

This is a light weight exhaust nozzle modification for the FMS Futura 64 mm EDF jet intended as a speed optimisation, not a thrust modification. The stock outlet on the Futura is approximately 58 mm. These designs reduce the exit diameter to either 55 mm or 54 mm in order to increase the velocity of the air leaving the fan. Higher exhaust velocity can improve maximum flight speed, although it may slightly reduce static thrust. These nozzles are intended for pilots interested in experimenting with EDF performance tuning rather than achieving a guaranteed upgrade. Do me a favour and ‘like’ this thing if you find it useful. ⸻ Why 55 mm and 54 mm? The stock Futura outlet is slightly larger than the effective airflow area of the fan (103%). This helps produce strong thrust for launching and climbing, but it is not optimised for maximum exhaust velocity. Reducing the outlet slightly increases the speed of the air leaving the fan, which in some setups can improve top speed. For this jet: • 55 mm is a moderate reduction and a good starting point (93%). • 54 mm is a more aggressive option that increases exhaust velocity further but may increase fan load (89%). Users can experiment with both sizes to see which works best for their setup. ⸻ These nozzles are experimental and are currently undergoing performance testing. Actual performance gains will depend on factors such as: • aircraft weight • battery condition and voltage sag • airflow quality through the duct • general airframe drag Users should expect modest changes, and results may vary. ⸻ The nozzle is designed to insert into the existing exhaust outlet of the Futura. It can be: • pressure fitted • secured with tape • lightly glued if desired Gluing is not recommended if you wish to experiment with different nozzle sizes later. But, If you do, I suggest only around the outlet mouth. ⸻ Reducing the exhaust diameter can: • slightly reduce static thrust • increase fan loading • increase current draw and system temperatures Monitor motor and ESC temperatures when testing. Because these designs increase exhaust velocity at the expense of some static thrust, launch performance may feel slightly softer compared with the stock outlet. ⸻ If your goal is maximum speed, reducing drag often provides larger gains than a nozzle change. The most effective modification is removing the fixed landing gear and flying the aircraft as a belly lander. Landing gear creates significant drag and its removal can produce a larger speed improvement than a nozzle change. Removing the landing gear means the aircraft will typically be hand launched and belly landed. I also have da esign available for servo horn covers that protect the control linkages when belly landing - https://www.thingiverse.com/thing:7302204 ⸻ Recommended Print Settings Layer Height: 0.12 mm Infill: 100% Supports: Enabled Material: PLA or PETG Speed: Slow Print with the nozzle exit on the print bed. ⸻ Final Note This nozzle is intended as a simple and reversible experiment for pilots who enjoy tuning EDF performance. Results will vary depending on setup and flying conditions.