7 pin_gap = 1.0; // around
14 hole_dia = th + pin_gap;
16 hinge_o_r = 0.5 * hole_dia + th;
18 hinge_x = -0.5 * tube_dia - hinge_o_r;
24 offset(r=-smooth_r) offset(delta=smooth_r)
26 translate([hinge_x, 0]) circle(r= hinge_o_r);
27 circle(r = tube_dia/2 + th);