This is my version of the Sikorsky-Boeing SB-1 Defiant next-generation helicopter. The shared design by Sikorsky and Boeing was designed to be a more maneuverable replacement for the UH-60 Black Hawk as a long-range attack helicopter. After a few upgrades to the helicopter, the two companies lost the contract bid for this vehicle in 2022 when the Army chose the Bell V-280 Valor instead.

This model has counter-rotating main rotors, which also turn the pusher propeller. It is kind of big, measuring in at about 16 inches long.

I designed this model in Blender, sliced it in ****, and printed it on an Ender 3 S-1 Pro using eSun PLA+ filament.

I used brass tubing for all drive shafts to the top and bottom rotors and to the pusher propeller.

To build this model, you will need three sizes of brass tubing: 7mm, 6mm, and 5mm.

Build the gearbox first, making sure to carefully glue the drive shafts to their corresponding gear and rotor hub, and the gear to the pusher propeller.

The spacer between the two main rotors ( I don’t know what that piece is called) is glued to the center section of the gearbox.

There is a printed tube that runs through the tail section from the gearbox to the pusher-propeller, so you need to make sure your infill of choice supports the shaft all the way through to ensure it doesn’t get a bend in it. I used 5% Grid infill in ****.

Sikorsky-Boeing SB-1 Defiant w/counter rotating rotors

0.2mm layer, 2 walls, 15% infill