Printed one to test and they work flawlessly! plus these look just like the ones that comes with the Sunlu spools which are my favorites! why bother designing one when someone has done it for me 👍🏻 thank you for that! Now I only have to print a few dozens haha 😜
I would add a little brim; and put concentric for the top layer pattern to have a nicer finish and prevent unnecessary retraction, but 5⭐ nevertheless 😉
Printed on my X1C with a 0.4mm nozzle using black BL PLA-CF, at 165% speed with lots of cooling.
They turned out great and fit perfectly on BL Filament Rolls. The brim was also very easy to remove and left no marks or stringing.