inner_radius = 8.0/2.0;
outer_radius = 25.0/2.0;
num_points = 40;
gear_width = 1;

thickness = 3.0;
thresh = 0.4;
protrusion_thickness = 2.0;
pi = 3.1415;




module gear(){
points = [ for (i = [0 : 1 : num_points]) (outer_radius  + gear_width * (i % 2)) * [ sin(360 / num_points * i), cos(360 / num_points * i) ] ];
    
difference(){
    union(){
    cylinder(r=inner_radius + 2.0, h=thickness + 2.0, center=true, $fn=100);
    linear_extrude(height = thickness, center = true, convexity = num_points) polygon(points);
    }
    cylinder(r=inner_radius, h=thickness + 2.0, center=true, $fn=100);
}
}

gear();