diameter_top = 120;
diameter_throat = 15;
diameter_bottom = 10;
height_top = 100;
height_bottom = 80;
wall_thickness = 1.2;
vent_pct = 100;
tab = false;
$fn = 50;

fuzz = 0.1;

radius_top = diameter_top/2;
radius_throat = diameter_throat/2;
radius_bottom = diameter_bottom/2;
top_vent_pct = vent_pct/1;
throat_vent_pct = vent_pct;
bottom_vent_pct = vent_pct;
tabsize=wall_thickness * 6;
tablength=0.75; // reasonable sizes range from 0.5 - 2.0
tabpos=90;

module ventblock_top(throat_vent, throat, angle, throat_h, hyp_b)
{
    // vent for top
    translate([throat_vent, 0, 0])
    rotate([0,0,180])
    translate([0, -throat, throat_h-fuzz])
    rotate([0,180+angle,0])
    cube([throat*2, throat*2, hyp_b*1.2]);
    
}

module ventblock_bottom(throat_vent, throat, angle, throat_h, hyp_b)
{    
    // vent for bottom
    translate([throat_vent, -throat, throat_h-fuzz])
    rotate([0,-angle,0])
    cube([throat*2, throat*2, hyp_b*1.2]);

}

module solidshape(w, h) {
    t = radius_top + w;
    m = radius_throat + w;
    b = radius_bottom + w;
    ht = height_top - h + w;
    hb = height_bottom - h - h - w;
    ft=m-((2*fuzz*(t-m))/ht);
    vt=(t - w) * (top_vent_pct/100);
    vm=(m - w) * (throat_vent_pct/100);
    vb=(b - w) * (bottom_vent_pct/100);
    mw = (t-vt-m+vm+fuzz);
    //mw = t-vt-vm;
    ab = atan((m-vm-b+vb) / hb);
    at = atan((mw) / ht);
    tcl = sqrt((mw^2)+((ht)^2))-fuzz;

    render() {
        difference() {
            union() {

                translate([0,0,h+fuzz])
                cylinder(ht+wall_thickness, t, ft);


                translate([0,0,ht+h+h])
                cylinder(hb, m, b);
            }
            

            // vent for bottom
            ventblock_bottom(m-vm, m, ab, ht+h, hb);
            ventblock_top(m-vm, t, at, ht+h, tcl);
            
            //translate([0,-m,0])
            //translate([0,0,ht])
            //rotate([0,180+at,180])
            //translate([m-vm, -m, 0])
            //rotate([0,180+at,0])
            //#cube([m*2, m*2, hb*2]);
            
            // vent for top
            //translate([t+t-m-vt-vt+vm, -t, -ht])
            //rotate([0,-at,0])
            //#cube([t*2, t*2, tcl*2]);
        }
        //color("red") x_measurement(0, [m-vm, 0, ht+fuzz-0.2]);
    }
}

module tabshape() {
    translate([-tabsize/2,0,fuzz])
    difference() {
        intersection() {
            cube([tabsize,tabsize*tablength*2,wall_thickness]);
            union() {
                cube([tabsize,tabsize*tablength,wall_thickness]);
                translate([tabsize/2, tabsize*tablength, 0])
                linear_extrude(wall_thickness)
                circle(d = tabsize);
            };
        }
        translate([tabsize/2, tabsize*tablength*0.9, 0])
        linear_extrude(wall_thickness)
        circle(d = tabsize/2);
        
    }
}

render() {
    union() {
        difference() {
            solidshape(wall_thickness, 0);
            solidshape(0,-wall_thickness);
        }
        if (tab)
        {
            rotate([0,0,tabpos])
            translate([0, radius_top, 0])
            tabshape();
        }
    }
}