Kingroon KP3S top mount spool holder with M5 screw holes

thingiverse

To not only rely on the snug fit of this spool holder I put two holes at its bottom to fasten it to the z-axis aluminum profile using two M5X20 screws or longer. The cutout for the screw head is 10 mm in diameter and 5 mm deep to fit tallow-drop screws and cylinder-head bolts. Of course you have to cut M5 threads into the aluminum profile to use this advantage!