Ultimachine Split-Spool Hack

thingiverse

I really like the design of a top mounted spool that rides on bearings, such as my Prusa-Top Spool Mount http://www.thingiverse.com/thing:16046 which was adapted from the MendelMax Spool Mount http://www.thingiverse.com/thing:13329 But after finishing my first spool, I faced a dilemna. Either: Continue to buy a new spool for every new filament batch, or Re-wind my empty spools with fresh filament. Buying a new spool every time not only costs extra, but I felt it would be quite wasteful, and BEING WASTEFUL IS FOR JERKS! Then I tried to re-wind a spool by hand. That turned into a tangled, frustrating mess very fast. I quickly realized that WINDING SPOOLS IS FOR CHUMPS! Being neither chump nor jerk, I devised a third option: a spool with a removable face, so that a coil of fresh filament could just be loaded on, and then reassembled. The printed parts along with some nuts and threaded rod help hold the split spool together. Parametric python scripts included for use with FreeCAD. Updated with a symmetric 3 "spoke" design to avoid pinching spool on one side. After testing this, the parallel-ness of my spool faces was improved and I decided to remove the old models with only one "spoke". Instructions The Ultimachine spool consists of three pieces that are very securely glued together. Two black faces on each side and a white center cylindrical section. I tried separating these pieces without cutting into them, by heating the glued joints and prying at them, but it did not look like it was going to budge at all. So, I had to cut one face off of the spool with a hacksaw. I cut just at the edge of where the spool face protrudes into the center section, keeping the face in tact. The white center section is slightly translucent, so you should be able to see where this is through the plastic. Cutting this straight with a hacksaw is pretty difficult. Instead of trying to cut straight through at once, I only cut the top edge and slowly rotated as I went. This might be much easier on a bandsaw if you have one. Once I had split this into two pieces, I chiseled the white pieces off around the smaller side using a sturdy flathead screwdriver and hammer. Test fit the two pieces together and check for parallel faces. If necessary, file or sand any high spots on the center section to make the faces parallel when put together. Take away as little material as possible to avoid making the spool too thin. When I was done, my cut was still very jagged, but the faces were parallel enough to work. Assemble with the two printed parts, some threaded rod, fender washers and nuts. 5/16" or M8 diameter should both work. Each side uses one fender washer and two nuts. The picture should make it clear how these are placed. Oh, and when loading reloading filament coil, don't take off the twist-ties until after the spool is reassembled :-)