Replacement K'nex chain link

myminifactory

My son unwrapped his roller coaster K'Nex kit on Christmas morning and, as expected, he quickly lost several critical links from the chain that made it functional. Rather than placing an order for replacements, I took a closer look to see if I could find a part to print myself. Scanning online stores, I found plenty of K'nex pieces but none of the elusive chain link. Undeterred, I broke out my calipers and fired up Fusion 360, determined to create a workable solution after just a few iterations. After about four attempts, I finally came up with a functional link that could be used in place of the original. While a complete chain made from these printed links might not perform as smoothly as the genuine article due to increased friction, eight of them strung together over 100 meters held up surprisingly well.