A remix of this clever mount by Urostro , for the original Mk3s Spool holder for the top of the Lack Enclosure. 

This is to allow you to avoid using all these silly roller/bearing spool holders on your lack enclosure. I've never seen any reason to not just use the original spool holder. The Bondtech extruder gears are well able to pull filament off that spool holder :-). 

Anyway, this remix increases the footprint of the part and adds some extra screw holes because the top of the lack table is very thin and spools be heavy yo.

Prints on its side with supports enabled. Enjoy