The available spool adapters for the CR-10 didn't meet my needs, so I designed a few of my own. Two sizes are available: 70mm diameter and 90mm diameter. 90mm diameter works perfectly for Tiny Machines' filament, which has a massive inner diameter.
I have optimized the pitch of the threads so that they print smoothly without the need for support, and they are coarse enough so the "bolt" and "nut" thread together with fewer twists.
As for any sort of play or "slop" in the threads, I iterated several times to find a fit that is both easy to thread and a firm connection at the same time. The tolerance of the nut and bolt is 0.3mm, so depending on your printer, you may need to scale up the NUT by 1-2% to suit your needs. DO NOT scale down the bolt, as it could cause the inner diameter to become too small and will not fit on the control box spool holder.
0.4 nozzle, 3 walls, WYZworks orange PLA filament, 50mm/s, 210/60C.