Three Bearing Swivel Nozzle (3BSN)

The 3BSN is a versatile thrust-vectoring mechanism for jet propulsion systems, commonly employed in VTOL and STOL applications. This project focuses on designing a 3D-printable 3BSN for integration into model RC platforms. Additionally, it serves as an exercise in leveraging Fusion 360’s component-based modeling features.

All designs are based on the SG-90 servo and 64mm 11 blade Electric Ducted Fan, hence the naming designation WS-6411.

WP-6411-CZ

  • The first attempt to create a 3BSN.
  • Duct sections are fixed by ball bearings and groove features.
  • Ball bearings separated by 3D printed spacers.

The initial design is a good proof of concept, but spur gear dimensions, duct sizing, bearing groove tolerance needed improvements.

Variant 1 (WP-6411-CZ M1)

  • Improved tolerance for printed grooves.
  • Changed spur gear to face gear to reduce drive gear size.

This modification significantly reduced the width (max OD) of the 3BSN, making it more practical to be installed on functional models. However, I wanted to cover any exposed gears and further optimize the dimensions as the system is still longer than anticipated.

Varnant 2 (WP-6411-CZ M2)

  • Improved bearing groove design.
  • Significantly compressed duct dimensions.
  • Reduced off-axis distance of the central duct.
  • Improved mounting bracket.

The latest modification, which is notibly more integrated. Total length is reduced by 19% (237mm to 192mm). The improved bearing groove design greatly helps alleviate 3D print tolerance issues.

Motion Simulation

And below is the only image I was able to find due to not having the habit to document things at the time of building…