Filament Spool Holder

thingiverse

A simple filament holder. It will hold spools up to approximately 70mm wide. It can be used on its own, however it will also fit into Rubbermaid 21 cup / 5 liter dry food containers that are popular as dry storage for filaments. The extras needed to complete the holder are four standard 685 ball bearings (5mm ID, 11mm OD, 5mm wide), and two 5mm axles (5mm metal rods will do just fine). The rods should be cut to length (about 86mm, give or take, size them up against the holder once it is printed). I'd recommend cutting them so that they have about 1mm to 2mm play side to side once installed; if cut too snugly they can extend past bearings and rub against supports. Any metal material should do (e.g. stainless steel, aluminum, etc), solid or hollow, as long as it can support weight of filament roll without getting bent. You'll need something suitable for cutting whichever type of rod you choose. Bolt cutters will cut through 5mm solid stainless steel rods, but they will leave uneven and sharp edge. Reciprocating saws, grinders, and dremel tools with appropriate saws or discs for cutting metals will make quick and clean cuts if used correctly. Always wear eye protection when working with metal and secure the part being cut! No matter what tool is used for cutting. Bolt cutters can send parts flying. Power tools with saws and especially grinding discs can send hot metal shavings flying around! File down sharp edges after cutting; make sure the rod slides smoothly into the ball bearing. Sometime the factory cut rods will have first 1mm or 2mm of rod deformed from cutting just tiny bit enough to make it very hard to slide bearings onto them. If this happens, file the ends a bit to get them to smoothly slide into ball bearing. Do not force rods into bearings; if it doesn't slide in smoothly, file it some more. To make dry box for filament, you'll also need a dry food box, e.g. Rubbermaid 21 cup / 5 liter dry food storage container is a popular choice. PC4-M10 PTFE pneumatic tube fittings to connect PTFE 2mm ID / 4mm OD tube into the box. With correctly sized hole (no larger than 3/8" or 9.5mm) drilled either near the bottom or top of container (depending where you want filament to exit), PC4-M10 fittings should self thread nicely into soft plastic and create airtight connection. If it feels loose (too large hole) you can always epoxy it in place permanently. A step drill will make a nice clean hole for the connector. Optionally, a round digital mini hygrometer/thermometer can be attached to the box. You'll likely want to drill hole for it with a hole saw, close to the top of the container (to make it easy to change battery) and run a bead of epoxy around the edge of hygrometer to make it airtight. Roughen up surface of plastic around the hole a bit with 220 or 320 grit sandpaper so epoxy has something to bite into, you don't have to overkill it, just make surface of plastic not smooth and not shiny. These small hygrometers are cheap, about $25 on Amazon for a box of 10 ($2.50 per hygrometer) and will tell you humidity level in the box; i.e. when it's time to replace silica gel desiccant so your filament stays dry. Rubbermaid food containers have very slippery bottom. To prevent holder from sliding back and forth in the box, put small balls of modeling clay in the four corner holes on the bottom of the holder, and press the holder down into the box once you position it. This should create non-permanent but sufficient bond to keep holder from sliding around inside the container.