openscad tiny gears (Might work for layer cutting?)

gears.scad

//cube([5,5,10]);

//cylinder(r=0.6,h=20);

holeWidth=1.6;
toothWidth=holeWidth+0.3;

pi=3.14159265359;


module gear(teath){
    circumference=teath*toothWidth;
    diameter=circumference/pi;
    difference(){
    circle(diameter);
    for (i = [1 : teath]){
        rotate([0,0,i *360/teath])translate([diameter,0])circle(holeWidth,$fn=18);
    
    }
    circle(r=diameter-toothWidth-0.5);
    }
    for(i = [1 : teath/2]){
        rotate([0,0,i *360/(teath/2)])translate([diameter/2-toothWidth,0])
        square([diameter,toothWidth], center=true);
    }
    
}

module internalGear(teath){
    circumference=teath*toothWidth;
    diameter=circumference/pi;
    circle(diameter);
    
    for (i = [1 : teath]){
        rotate([0,0,i *360/teath])translate([-diameter,0])circle(holeWidth,$fn=18);
    
    }

}


function gearDiameter (teath)=(teath*toothWidth)/pi;


module holeGear(){
translate([(gearDiameter(8)*2)-toothWidth/2,0])
  rotate([0,0,22])
  linear_extrude(height=0.3*2)difference(){
  union(){
    gear(8);
    circle(3);
  }
  circle(1.2,$fn=10);
}

}

holeGear();
translate([11,0,0])holeGear();
translate([22,0,0])holeGear();


linear_extrude(height=0.3*2)gear(8);

translate([-25,0,0])

difference(){
union(){
    
linear_extrude(height=0.3*5)for(i = [1 : 3]){
      rotate([0,0,i *360/3])
      translate([0,gearDiameter(21)+3])rotate([0,0,i *360/3])
          circle(r=2);
    }
    
linear_extrude(height=0.3*5)
difference(){
  circle(gearDiameter(21)+3);
  rotate([0,0,45])internalGear(21);
}
difference(){
  cylinder(r=gearDiameter(21)+3,h=0.3);
  translate([0,0,-0.1])cylinder(r=gearDiameter(8),h=2);
}
}

linear_extrude(height=10)for(i = [1 : 3]){
      rotate([0,0,i *360/3])
      translate([0,gearDiameter(21)+3])rotate([0,0,i *360/3])
          circle(r=1);
    }

}

translate([0,25,0]){
linear_extrude(height=0.3*6)gear(8);
linear_extrude(height=0.3*2)

for(i = [1 : 3]){
    rotate([0,0,i *360/3])
    difference(){
    union(){
        translate([0,(gearDiameter(8)*2)-toothWidth/2])circle(r=2.5);
    translate([-2.5,0])square([5,8.6]);
    }
    translate([0,(gearDiameter(8)*2)-toothWidth/2])circle(1.2,$fn=10);

    }
}
}

translate([0,-25,0])
difference(){
  union(){
    cylinder(r=gearDiameter(21)+3,h=0.3);
    linear_extrude(height=0.3)for(i = [1 : 3]){
      rotate([0,0,i *360/3])
      translate([0,gearDiameter(21)+3])rotate([0,0,i *360/3])
          circle(r=2);
    }
  }
  translate([0,0,-0.1])cylinder(r=2,h=4);
  linear_extrude(height=0.4)for(i = [1 : 3]){
    rotate([0,0,i *360/3])
    translate([0,gearDiameter(21)+3,])rotate([0,0,i *360/3])
          circle(r=1);
    }
}