Dremel jig for putting holes in bottle caps
If you want to put a hole in a bottle cap and don't have a bit large enough, but have a Dremel with a 561 Multipurpose bit, this offset jig will make it easier to get a (mostly) round hole.
Fusion 360 file sketch dimensions can be changed to adjust for bottle cap diameter and desired hole diameter.
FYI: the Dremel collar is a 3/4" 12 TPI UN thread.
Update: the F3D file is slightly improved to handle parameterization better.