bearing supported spool cradle with filament guide (fits Wanhao i3 built-in bolt holes)

thingiverse

This is a compact filament spool holder supported by ball bearings that can be mounted using the Wanhao i3 frame spool bolt holes and has an integrated filament guide. The filament guide is a captive ball joint designed to accommodate 4mm diameter Teflon tubing. I still need to develop a reliable solution for capturing the bottom end of the filament guide tube at the extruder, so I'm currently using a short length of Teflon tubing secured only at the guide end to maintain control over the filament as it leaves the spool. My primary objectives in designing this cradle were to achieve compactness, utilize ball bearings for low friction and minimal force required to pull filament off the spool, and ensure control over the filament while providing sufficient friction in the filament guide to prevent excessive rotation of the filament spools on the ball bearings as they unwind. The filament cradle is printed as a single unit. The spindle is designed to accept two end caps (referred to as bobbins) with suitable spacers to guarantee that the end caps are centered on the spindle. This design was originally created for my Monoprice 1kg spools, and the end caps fit the Monoprice spool bore. With the Monoprice inner spacers, the Monoprice end caps, and the spindle, the end caps touch the inner ring of the skateboard-style (VXB 608 ZZ) ball bearings to keep the spool centered and secured on the spindle. I have designed inner and outer spacers, as well as an end cap, that will enable Hatchbox 1kg spools to be mounted on this cradle. I am currently printing these out for testing purposes, and they will be added to this project once their dimensions are confirmed to be accurate. I invite others to create parameterized versions of the end cap, the spacers, etc., allowing individuals to easily accommodate other brand spools on this cradle. To facilitate this process, I have attached my SolidWorks source files for these parts. As a beginner in SolidWorks and with this being my first project using the software, I acknowledge that my approach may not be optimal. Additionally, if someone has any innovative ideas to improve the spindle/end cap combination design, making it more versatile, simple, or whatever they deem beneficial, please feel free to implement them and share the results back to this cradle project. As a novice in designing things, I am aware that there are likely many more efficient ways to achieve this, and I would appreciate seeing any alternative solutions. EDIT 13 November 2016: I have just added STL files for inner spacers and end caps designed specifically for the eSun 1kg spool and the Hatchbox 1kg spool. This cradle now includes everything necessary to support Monoprice, eSun, and Hatchbox 1kg spools. As I come across new brands with different spool widths and bores, I will design end caps and inner spacers to accommodate them on my cradle, and they will be added to the project. These designs are straightforward for any arbitrary spool that fits within this framework, which should cover most spools.