cylinder(h=bottom_thickness / 2, r=(bushing_z[0] + 5 * single_wall_width));
}
//smooth rod hole
- translate([board_to_xz_distance - z_delta, 9, -1]) cylinder_poly(h=board_thickness+20, r=bushing_z[0] + single_wall_width / 4);
+ translate([board_to_xz_distance - z_delta, 9, -1]) cylinder(h=board_thickness+20, r=bushing_z[0] + single_wall_width / 4);
//inside rouned corner
translate([0, 5, -1]) cylinder(r=0.8, h=100, $fn=8);
//side screw