Swappable Spool Holder

This design is very loosely based on the concept of the great Parametric customisable one from shaunp. What I missed was how with the official makerbot spool holders you can click on a spool and it can't fall off (even when tilting your bot)... and how nice the holder clips onto the back of my Replicator 1.

This Holder comes in two parts... a clip that slots onto your Replicator, and a shaft that slots into the clip... on this you can mount your spool.

I made two versions of the shaft.. th