About this 3D model

This is sized to work ideally with Hatchbox spools which are ~68mm outside to outside. Will also work with many others that are close (~+/-5 mm -maybe more). It is shown on a no-name brand spool that was ~64mm wide. Spools will flex a bit so it doesn't have to be perfect. I match drilled and used #6 wood screws to attach to spool.