Dirt cheap filament dry store & feed

thingiverse

Inspired by Kevin O'Connor's [zipspool](https://github.com/KevinOConnor/zipspool/), this is a system for feeding filament directly from zip bags. I wanted to avoid the need for additional table/shelf space by the printer and stick with the existing (stock) spool holder on top of my Ender 3, but the system here should be compatible with pretty much any holder that's anchored only on one side. The only parts needed are one 2-gallon or comparable size zip bag and a small 3D-printed port for the filament to pass out of the bag. A pack of silica gel dessicant can also be thrown inside the bag for extra moisture protection if desired. To assemble, poke a small hole (under 8 mm diameter) through the seam on one side of the bag (around mid-height works well) and press the bolt out through the hole from the inside, then tighten the nut onto it from outside, letting the flanges press firmly against the bag to prevent it from being torn by sudden extruder motions. Insert the filament spool into the bag and thread the end of the filament out through the port. Then, reaching inside the bag, pull the *bottom corner* of the bag on the *side opposite the port* through the opening in the center of the spool. Squeeze out excess air and seal the zip bag. It should now rest on the holder. During printing the bag does not spin, but it may wobble with tensioning and retraction of the filament. The bag itself acts as a reasonably low friction bearing for the spool to spin inside while the extruder tensions the port and thus the entire bag in place. If using the spool holder on top of the Ender 3 or similar, a filament guide is highly recommended. Otherwise you're likely to get friction in places that will interfere with printing. I use [Ender 3 Filament Roller Guide by Holspeed](https://www.thingiverse.com/thing:3052488) and am very happy with it.