Filament Guide and Spool Enclosure

myminifactory

A filament guide and spool enclosure for the Prusa i3 MK3 printer gets the filament spool off the top of the frame and provides a bit of humidity protection if you leave your filament loaded for a few days. It consists of three main assemblies. PTFE Tube Guide: The PTFE tube guide consists of a Guide Bracket, which snap fits into the z-axis-top part hexagonal opening and extends a threaded opening over the build plate. The opening accommodates the PTFE tube lock, which is a slotted, tapered tube through which the PTFE guide tube is passed. An integrated thumb screw provides the means to adjust the locking force preventing axial movement of the PTFE tube. The PTFE tube terminates at the Threaded Filament Sensor Cover, which accommodates a PC4-M6 push fitting to lock the PTFE tube to the filament sensor cover. A 77 cm length of PTFE tube and a push fitting are the only non-printed components required. Spool Case: This fully 3D printed enclosed spool holder is assembled from a foldable Hex Panel component with "permanent" snapfit joinery. Assembly is nearly toolless (pliers likely required to snap some of the joints together unless you have fantastic finger strength). The two case halves are finished with a set of Rails and Stiles. The rails incorporate a light, snap-fit closure between the two case halves and the lower set of rails integrates the spool axle cradle. To allow the filament to pass through the case, a Hex Panel Port receives a snap-fit, threaded Tube Flange through which another adjustable PTFE Tube Lock is installed. A Gel Cover and associated Plug allows loose silica gel desiccant to be contained in a hex panel. Though not air-tight, the fit of the case parts is close enough to allow silica gel to maintain an internal humidity lower than that of the external environment for at least a couple days. Spool Axle: Also fully 3D printed, the adjustable axle assembly accommodates various filament spool widths with two threaded Spool Flanges, each of which incorporates a print-in-place gear bearing. The Flex Axle, which was printed in vase mode, has an integrated spring design to reduce lateral movement of the spool flanges. The assembly nominally handles filament spools with through-hole diameters of 48 to 75 cm and widths from 40 to 70 cm, but is dependent on a spool's specific combination of diameter and width. I'd like to continue to improve the design... I hope you give these parts a try and let me know how it goes. The Spool Axle assembly is one of the most satisfying prints I've produced and each time I see those gear bearings print, it makes me happy!