// Parametric snap-on bar clip  (units: mm)
// Fine tune bar_d to match your bar. 0.5 in = 12.7 mm.
bar_d     = 12.7;   // bar diameter
thickness = 25.4;   // clip thickness along the bar (1 in = 25.4)
clearance = 0.2;   // extra room around the bar
wall      = 3.0;   // ring wall
gap_ratio = 0.8;   // snap opening / bar diameter
base      = true;   // flat mounting base
base_w    = 40.0;
base_t    = 4.0;
$fn = 96;

ri  = bar_d/2 + clearance;
ro  = ri + wall;
gap = min(gap_ratio*bar_d, 2*ri*0.99);

linear_extrude(height = thickness) difference() {
    union() {
        circle(r = ro);
        if (base) translate([-base_w/2, -ro - base_t]) square([base_w, base_t + min(1, wall/2)]);
    }
    circle(r = ri);
    // snap opening at the top
    translate([-gap/2, 0]) square([gap, ro + 1]);
}