Tension nut and filament guide for 1/2 inch EMT conduit

EDIT: Added new version (tension_nut_filament(1)). I didn't account for the increased hub hole on my larger spools which resulted in these spools dragging. New version has an additional 30mm arm length. Also added a toothed clip for holding the filament when not loaded. The clip is based upon thing 630789. This is convenient if you have multiple spools loaded on your EMT at once.

Based upon the design of coconnor55, I created a version that fits 1/2 inch EMT conduit. The nut was designed usi