// nBTC v0.2 concept shell. No electronic security or monetary value is created.
// Export base and lid separately. Measure the insert and test fit before assembly.
part = "base"; // "base", "lid", or "layout"
diameter = 45;
base_height = 4.4;
lid_height = 0.8;
tag_diameter = 28;
tag_thickness = 0.8;
clearance = 0.4;
$fn = 120;
assert(tag_diameter + 2*clearance < diameter - 4, "Keep at least a 2 mm side wall");
assert(tag_thickness + clearance < base_height - 1, "Keep a solid base floor");
module base() {
    difference() {
        cylinder(d=diameter, h=base_height);
        translate([0,0,base_height-tag_thickness-clearance])
            cylinder(d=tag_diameter+2*clearance, h=tag_thickness+clearance+0.01);
    }
}
module lid() {
    cylinder(d=diameter, h=lid_height);
    translate([0,3,lid_height]) linear_extrude(0.5)
        text("nBTC", size=8, halign="center", valign="center");
    translate([0,-9,lid_height]) linear_extrude(0.3)
        text("DEMO", size=3, halign="center", valign="center");
}
if (part == "base") base();
else if (part == "lid") lid();
else if (part == "layout") {
    translate([-diameter/2-3,0,0]) base();
    translate([diameter/2+3,0,0]) lid();
}
else assert(false, "part must be base, lid or layout");