pcd measurement turned into a bolt hole pattern using OpenScad (customizable)

thingiverse

How do you create a fitting with equidistant holes in a cylindrical shape? OpenScad code is provided below. // Define the circle radius 'a' which translates from the center so this is half the pitch circle diameter (PCD). a = 15.5; // Initialize counter variable 'i'. i = 0; // Set the number of sides for smoothness to 120. $fn = 120; difference() { // Create a cylinder with thickness 10, outer diameter 20, and height 20. cylinder(10, 20, 20); // Rotate and translate to place holes at equal intervals around the circle. for (i = [0:60:300]) { rotate([0, 0, i]) translate([0, a, -10]) // Create holes with diameter 3mm and depth 20. cylinder(20, 3, 3); } }