The dirty little secret in the world of 3D printing is that things go wrong (a lot). This week’s problem to solve is the frequent cross-threading of the rolls of filament itself. Filament manufacturers don’t seem to understand the requirements necessary for doing this right so it’s up to the rest of us to fix the problem ourselves.
Each time cross-threading occurs during a print job, you lose the entire print since the feeding of that filament just stops. In this photo, the printer has actually lifted the entire holder assembly off the workbench:
To deal with this problem, I decided to re-invent the spool holder itself by changing the inner topology from a rectangular shape to parabolic. It now delivers filament in a straighter path to the filament sensor block on the printer, minimizing cross-threading.
The reusable spool guide design incorporates eight individual parts which attach together using standard aluminum hex head bolts.