I’ve been playing with this idea for couple months – let’s design my own thrust vectoring nozzle! As always, Wikipedia provided some initial thoughts.

module outer_solid(dm, size, diff) {
cylinder(size+diff+10, dm-7, dm-7, center = false);
Ty(dm+2)
Rx(90)
cylinder(dm*2+diff+4, dm, dm, center = false);
}
module rim(r = 1) {
rotate_extrude(convexity = 10)
translate([38.5, 0, 0])
circle(r);
}
module outer_part() {
difference() {
union() {
difference() {
outer_solid(40, 55, 0);
outer_solid(38.5, 55, 2);
}
Ty(-41)Rx(90)
rim();
}
T(-55, -43, -45)
Ry(45)
cube(81.5, center = false);
//outlet cutout
Tz(-39)
scale([1,0.66,0.555])
sphere(60);
}
}
module inner_solid(dm, diff) {
//cylinder
Ty(dm+2)
Rx(90)
cylinder(dm*2+diff+3.5, dm, dm, center = false);
//exhoust
Rx(180)
Tz(26)
scale([0.9,1.4,1])
cylinder(65+diff/2, 27-diff/2, 20-diff/2, center = false);
}
module lever() {
Ty(-44)Rx(90){
difference() {
union() {
//core
cylinder(10, 7, 7, center = true);
//lever
Tz(6)
scale([5,1,1])
cylinder(2, 7, 7, center = true);
}
//bolt holes
T(30,0,5.5)
cylinder(4, 2, 2, center = true);
T(-30,0,5.5)
cylinder(4, 2, 2, center = true);
}
}
}
module inner_part() {
//inner cylinder
Rz(180)
difference() {
inner_solid(38.2, 0);
inner_solid(36.7, 2);
T(0, 0, -120)
cube(60, center = true);
//inlet cutout
Tz(31)
scale([0.62,0.6,1])
sphere(60);
}
//exhoust rim
scale([0.462,0.712,1])
Tz(-89.8)
rim();
//main cylinder reinforce rim
Ty(38.5)Rx(90)
scale([0.96,0.96,1])
rim();
//lever
color("grey")
lever();
}
$fn = 100;
outer_part();
inner_part();
If you run that code above in the OpenSCAD, you’ll get this:

I actually had a bit of fun and made it into a screencast.
Bit of playing in CURA, came with a sliced a 3D model for a printer (GCODE).

Then it took 18 hrs to print!
Well, I think it was worth waiting. π
All clicked together and moving smoothly. I was surprised how nicely it actually worked out. Still, there are few things to improve:
- Find out how to attach the control servo
- With higher pressures that inner piece tends to pull out a bit – creating a leak
- Inner part might be cutout bit better to block inlet less
- Inlet tube to fit properly our PVC tube (now same-ish diameter)
- Consider a gimball shape to avoid turbulences in that inner cylinder
Still it looks beautiful for a first try π
