Inland/esun refillable spool

I haven't printed this yet to test it, but I've printed the center spindle to check for fitment issues. I remixed an existing design that wasn't designed to be functional and tweaked it in such a way as to both make it functional and also save some filament on the print. This is sized for the Inland/esun spoolless refills which come on a cardboard core and are NOT Masterspool compatible.

This uses the same nuts and bolts as the official inland/eSun spool. The inland-branded refillable spools come with an extra set of nuts and bolts so if you have purchased one of those, you should already have the necessary parts. The bolts are M6x34 and you will need two bolts and two matching nuts. Just print two of these half-spools and attach them with the requisite hardware and you're good to go.