second=70;
r_final_gear=second/2 - 5;
r_motor_gear=3;

bublator_width=0.4 * second;
bublator_length=2*r_final_gear;

r_hat=150/2;

// dimensions of the nails used as pins and axis
r_nail=1.4/2;
r_nail_head=2.5/2;

$fn=100;

module nail_rail() {
    cube([5, 200, 2], center=true);
    translate([0, 0, -1.99]) cube([2, 200, 2], center=true);
}

module motor_gear(angle=0) {
  r=r_motor_gear;
  rotate(angle)
  difference() {
    // the actual gear
    cylinder(r=r, h=5, center=true);

    // pulley rim
    difference() {
      cylinder(r=r+1, h=3, center=true);
      cylinder(r=r-0.5, h=5, center=true); 
    }
    difference() {
      cylinder(r=r+1, h=2, center=true);
      cylinder(r=r-1.0, h=5, center=true); 
    }

    // central nail hole
    cylinder(r=r_nail, h=100, center=true);
    translate([0, 0, -4]) cylinder(r=r_nail_head, h=2);
  }
}

module final_gear(angle=0) {
  r=r_final_gear;
  rotate(angle)
  difference() {
    // the actual gear
    cylinder(r=r, h=5, center=true);

    // pulley rim
    difference() {
      cylinder(r=r+1, h=3, center=true);
      cylinder(r=r-0.5, h=5, center=true); 
    }
    difference() {
      cylinder(r=r+1, h=2, center=true);
      cylinder(r=r-1.0, h=5, center=true); 
    }

    // air hole
    translate([0, -r/2, 0])
    cylinder(r=0.4 * bublator_width, h=10, center=true);

    // excentrical nail hole
    translate([0, r-3, 0]) {
      cylinder(r=r_nail, h=100, center=true);
      translate([0, 0, 1]) cylinder(r=r_nail_head, h=2);
    }

    // central nail hole
    cylinder(r=r_nail, h=100, center=true);
    translate([0, 0, -4]) cylinder(r=r_nail_head, h=2);
  }
}

module bublator(angle=0) {
  r=bublator_width;
  color([0, 0.7, 0])
  translate([0, (r_final_gear-3) * (cos(angle) - 1), 0])
  difference() {
    union() {
      cube([bublator_width, bublator_length, 5], center=true);
      translate([0, bublator_length/2 - 3, 0]) cube([r_final_gear*2 + 5, 10, 5], center=true);
    }

    // bubble hole
    translate([0, r_final_gear/2 - bublator_length/2, 0]) {
      cylinder(r=0.4 * bublator_width, h=10, center=true);

      // nipple array ... hooray
      for (i = [1:30])
      for (j = [-1,1])
      rotate(i * 360/30)
      translate([0, 0.4 * bublator_width - 0.5, 0])
      rotate([90 + j*70, 0, 0])
      rotate([0, 0, 45])
      cylinder(r1=0, r2=3.5, h=6, center=true, $fn=100);
    }

    // nail hole
    translate([0, bublator_length/2 - 3, 0])
    cube([2*(r_final_gear - 2), 2.5 * r_nail, 50], center=true);
  }
}

module assembly_clearance() {
  translate([0, 18, -1])
  linear_extrude(170)
  minkowski() {
    square(0.3, center=true);

    projection()
    rotate([90,0,0]) moving_assembly();
  }
}

module arc(r, d) {
  intersection() {
    translate([0, -r + d, 0]) circle(r);
    translate([0, 500]) square([1000, 1000], center=true);
  }
}

module tank() {
  color([0.3, 0.3, 0.9])
  translate([0, -18, -2*r_final_gear])
  difference() {
    union() {
      // bottom
      linear_extrude(1.5) arc(r_hat, 30);

      // flooding protection floor
      translate([0, 0, 2*r_final_gear - 2])
      linear_extrude(1.5) arc(r_hat, 30);

      // walls
      linear_extrude(4 * r_final_gear + 2)
      difference() {
        arc(r_hat, 30);
        translate([0, 1.5, 0]) arc(r_hat, 27);	
      }

      // bublator_rails
      for (i = [-1,1])
      translate([i*r_final_gear, 18, 2*r_final_gear + 0.5])
      rotate(-i*25)
      cube([10, 10, 4*r_final_gear], center=true);

      // gear holding protrusion
      translate([0,0,1.6*r_final_gear])
      intersection() {
	rotate([-90, 0, 0])	
        translate([0, -20, 0])
	cylinder(r=r_final_gear, h=70, center=true);

	translate([0, 5, 30])
	cube([100, 9.7, 40], center=true);
      }
    }

    // rear air hole
    translate([0,0,1.6*r_final_gear])
    rotate([-90, 0, 0])	
    translate([0, -27, 0])
    cylinder(r=0.4*r_final_gear, h=50, center=true);

    // front air hole
    translate([0,0,1.6*r_final_gear])
    rotate([-90, 0, 0])	
    translate([0, -27, 30])
    rotate([30, 0, 0])
    cylinder(r1=0.31*r_final_gear, r2=0.85*r_final_gear, h=30, center=true);

    assembly_clearance();

    // pulley clearance
    translate([-r_final_gear - 90, 11, 2*r_final_gear])
    cube([100, 3, 2*r_final_gear - 2]);

    // gear axis hole
    translate([0, 20, 3 * r_final_gear])
    rotate([90, 0, 0])
    cylinder(r=r_nail, h=100);

    // bublator screw assembly hole
    translate([0, 0, 4*r_final_gear])
    rotate([90, 0, 0])
    #cylinder(r=20, h=30, center=true);
  }
}

module cage() {
  linear_extrude(2*r_final_gear)
  assembly_clearance();

  tank();
}

module moving_assembly(angle=0) {
  // distance 0.25 mm between objects
  translate([0, 0, 5.25]) final_gear(a);
  translate([0, -bublator_length/2 + second/2 - 5, 0]) bublator(a);
}

a=0;//$t * 1000;

translate([0, 0, r_final_gear])
rotate([90, 0, 0])
moving_assembly(a);
tank();

translate([-70, -5, r_final_gear - 20])
rotate([90, 0, 0])
motor_gear();

! tank();