door_thick = 50;
flap_w = 150;
flap_h = 150;
flap_thick = 20;
angle = 10;
bearing_inner_dia = 5;
bearing_outer_dia = 10;
bearing_h = 5;
silver = [0.7,0.7,0.7];
red = [1,0,0];
$fn = 32;
ry = [0,90,0]; // rotate 90 deg around y
raise_stopper = -1;
gap = 1;

module door(){
    translate([-450,0,0])cube([900,door_thick,2000]);
}

module flap(){
    difference(){
        translate([flap_w,flap_thick,0]/-2)
            cube([flap_w,flap_thick,flap_h]);
        translate([2*(10+gap)+bearing_h,bearing_outer_dia+gap,2]/-2)
            cube([bearing_h+2*(gap+10),bearing_outer_dia+gap,2*bearing_h+20+gap+1]);
    }
    translate([0,0,raise_stopper])stopper();
}

module bearing(){
    color(silver)
        rotate(ry)
            difference(){
                cylinder(d=bearing_outer_dia,h=bearing_h,center=true);
                cylinder(d=bearing_inner_dia,h=bearing_h+2,center=true);
            }
}

module bearing_case(){
    rotate(ry)
        cylinder(d=(bearing_inner_dia+gap)/2,h=bearing_h+gap);
    translate([(bearing_h+gap)/2,0,bearing_inner_dia/2])
        rotate(ry)
            cylinder(d=bearing_outer_dia,h=10);
    translate([(bearing_h+1)/2,-bearing_outer_dia/2,0])
        cube([10,bearing_outer_dia,bearing_h+20]);
    translate([0,bearing_outer_dia/-2,bearing_h+1])
        cube([bearing_h,bearing_outer_dia,19]);
}

module stopper(){
    color(red){
        bearing_case();
        rotate([0,0,180]) bearing_case();
    }
    bearing();
}

*door();
flap();