This is a working zipper mechanism. I printed it as an experiment, inspired after the zipper on my wife's coat broke. (I don't think I can print a replacement, yet.) There might be applications to join small sections of a structure to make a large object, but mostly it's a toy.Print two of the ZipperHalf parts and one ZipperY. I sized it to fit well with my Thing-O-Matic using an original MK6 Stepstruder. Clean up any stringers. There may be some small chaff on the print, but manually interlocking the zipper teeth a couple times will allow the Y section to zip it fairly smoothly.There's no provision to unzip it, just pull the two sections apart.This works as is, but I marked it as a work in progress because once I get a MK7 Stepstruder I may try to make some refinements, including an unzip mechanism.