Thrust vectoring

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. 🙂

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 🙂