This is a Filament Splitter designed to be used with m4 setscrews since friction fit was not reliable enough for me. I designed it primarily for use with AMS. The curved entry is for AMS and the straight entry for external spools (since the curvature helps with filament guidance).

for 1.75mm Filament only!

The smaller the layer height the better. 0.1mm is sufficient. Print standing up!

(Yes you could make both the external spool entry and the AMS entry curved but in my case straight was preferable.)