This bobbin clip is based on a model for a Singer bobbin clip shared by @DebClutter. The Singer clip was the same diameter as a class 15 bobbin, but was 3.7mm shorter. A Class 15 bobbin is  1"/21mm diameter x .4"/11mm height. I extruded the original model an additional 3.7mm and the new model fits my wife's bobbins perfectly! I used a 3mm brim and no glue to print these on a Bambu Textured PEI plate with Bambu PLA. The brim peeled off the prints without any issues. I retained the licensing of the original designer, with the addition of Share Alike.