Printing an object with threads is nothing new. If you know the specifications on the other thread or you are in control of it, no problem. But [Shop Therapy] wanted to print parts that mate with an existing unknown thread. Out come the calipers.

The first measurement is the height. He rounded that up in the video but mentioned in the comments that it should really be a little smaller so that it seats properly.

After that, he measures the pitch and the major diameter. Next, of course, is the minor diameter. The pitch is related to the spacing of the threads, the major diameter is the diameter of the outside part of the threads, and the minor diameter is the neck without threads.

Next, he’s off to Fusion 360 to design the matching cap. Of course, you could use whatever 3D CAD software you like. Fusion does have some nice thread-related operations, and while it isn’t exactly free, you can get licenses for personal use with no difficulty.

Printing threads has its ups and downs. We prefer embedding metal threads into our prints.