pen_diameter=9;  // stabilo: 9mm // weitere: 11mm
height=65;
thick=1.5;

$fn=100;

module rubberband_fix() {
    translate([1.5,0,0]) cube([pen_diameter/2+2*thick-3,1.5,1]);
    translate([0,1.5,0]) cube([pen_diameter/2+2*thick,1.5,1]);
}

module all_rubberband_fix() {
            translate([0,pen_diameter+2*thick,47+4+4*thick+2]) rubberband_fix();
            translate([0,pen_diameter+2*thick,47+4+4*thick+2-12]) rubberband_fix();
            translate([0,pen_diameter+2*thick,47+4+4*thick+2-24]) rubberband_fix();
            translate([0,pen_diameter+2*thick,4+thick]) rubberband_fix();
            translate([0,pen_diameter+2*thick,4+thick+12]) rubberband_fix();
            translate([pen_diameter/2+2*thick,0,47+4+4*thick+2]) rotate([0,0,180]) rubberband_fix();
            translate([pen_diameter/2+2*thick,0,47+4+4*thick+2-12]) rotate([0,0,180]) rubberband_fix();
            translate([pen_diameter/2+2*thick,0,47+4+4*thick+2-24]) rotate([0,0,180]) rubberband_fix();
            translate([pen_diameter/2+2*thick,0,4+thick]) rotate([0,0,180]) rubberband_fix();
            translate([pen_diameter/2+2*thick,0,4+thick+12]) rotate([0,0,180]) rubberband_fix();
}

difference() {
    union() {
        cube([pen_diameter/2+2*thick,pen_diameter+2*thick,height]);
        translate([-22,0,4]) cube([22,pen_diameter+2*thick,47+4*thick]);
        translate([-3,0,1]) cube([3,pen_diameter+2*thick,1]); // rubber band bottom
        translate([-3,0,47+4+4*thick+2]) cube([3,pen_diameter+2*thick,1]); // rubber band top
        all_rubberband_fix();
    }
    translate([pen_diameter/2+thick,pen_diameter/2+thick,-0.2]) cylinder(r=pen_diameter/2,h=height+0.4); // pen
    translate([-20-12,0,4+2*thick+7]) cube([20,pen_diameter+2*thick,47+thick-7-1]); // fan
    translate([-30,0,4+2*thick]) cube([30,pen_diameter+2*thick,7]); // plate
    translate([-20-9,0,4]) cube([20,pen_diameter+2*thick,2*thick]); // bottom
    //#translate([-30,0,0.33*height]) cube([30,pen_diameter+2*thick,2]); // rubberband cutout
    //#translate([-30,0,0.66*height]) cube([30,pen_diameter+2*thick,2]); // rubberband cutout
}