When you really start fine-tuning your 3D printer, you may find that even the smallest things can have a noticeable impact on your prints. An open window can create enough draft for your print to release from the bed, and the slightly skewed diameter of this inexpensive basement filament can affect your rate of extrusion. It can be a deep rabbit hole that falls down if you’re not careful.
One element that is often overlooked is the filament spool; If it doesn’t spin smoothly, the drag it puts on both the extruder and the movement of the printhead can lead to difficult-to-diagnose problems. For his purpose-built printer, [Marius Taciuc] has developed a very clever printable device with which the filament roll can only be rotated with the properties of the PLA itself. While the design may need a bit of tweaking to work on your own printer, the files it shares should get you most of the way there.
All you have to do is print out the hubs that will fit your particular filament spools (of course, they aren’t all a standard size) and snap them on. The hub’s four “claws” lightly touch a piece of 8mm rod sufficient to support the spool while limiting the surface area as much as possible. The natural elasticity of PLA helps to dampen the moment that would arise if you just hung the hubless spool on the rod.
The STL files [Marius] for its low-friction hubs should work for anyone wanting to try out its design, but you’ll need to come up with your own method to mount the 8mm rod in a convenient location. The arms that come with it are specially designed for his bespoke Prusa Mendel, which is quite a long way from modern desktop 3D printer design. You might want to consider a piece of 8mm rod suspended above the printer that has enough space to put on a couple of spools so you can quickly access a variety of colors or materials.
Hackers have been trying to solve the coil friction problem for years, and as you’d expect, we’ve seen some very clever designs in the past. But most of all we like how easy it is [Marius] made this design and the fact that you don’t need to source bearings to build it. If you’re thinking of giving this new design a try, be sure to leave a comment so we know how it worked for you.