The Pop-A Bobbin shuttles I have been using come with a pin in it and an extra pin in case you lose one. I got to wondering what would I do if I lost both. Then I looked at the 3D printer. I opened Rhino 3D. I drew a pin. I printed 2. They work! And they only take 10 minutes to make. I just keep finding things to print, and for the most part, they are useful.