Ender 3 Hatchbox BB bearing

thingiverse

This is a bearing I designed to fit with my Ender 3 and Hatchbox PLA filament spool. Additional Tools: BBs (0.18") Glue Tooth pick or something else that's small and thin WD40 220 Grit sand paper Abstract: Described is a novel bearing design that utilizes BBs for smoother movement. This bearing is designed to fit on the inside of a hatchbox filament spool and allow for smoother rotation on an ender 3 filament peg. Due to it's design, it can serve as a blueprint for future bearing models. Motivation: The Ender 3 comes with a peg for the spools to sit on but it doesn't allow for them to rotate that nicely. I've been having some issues with extruder skipping and I figured that once source of the issue is likely due to there being too much force needed to pull on the filament sometimes. I decided if the spool could rotate on a bearing it would be a lot smoother (in addition to using a filament guide) However, I didn't think that existing 3D printable bearing designs were that great so I've come up with a new type of bearing (at least I think it's novel) that uses BBs as the bearings to allow for really smooth rotation. Methodology: To create a single bearing, print the inner and outer rings once, and the ball_ring twice.You will need two bearings for a total of two inner and outer rings, and four ball rings. Before assembly liberal sanding with 220 grit is advised. To assemble you will need ten standard .18" BBs per bearing. Place the inner ring within the outer ring and place ten BBs all on one side. Carefully pinch the inner and outer ring to hold the BBs in place and delicatley place one ball ring underneath. The ball ring should now be in the middle between the inner and outer ring with all the BBs still bunched to one side. It won't fit together that well, that is normal. Now, slowly rotate the inner ring relative to the outer one (direction is irrelevant) the BBs should move relative to the ball ring, if they are not, get a small thin tool like a needle and manually rotate the ball ring relative to the others. As this rotation occurs, the notches should catch the BBs and they will fall into place one at a time. You might have to poke at them occasionally. When the last BB falls into place it will snap together. The last step is the most difficult. Squeeze out a small amount of super glue and pick up a tiny amount on the end of a tooth pick and place very tiny dabs on the second ball ring in the spaces between the ball notches. Carefully use a tweezer to place the second ball ring into the rest of the assembly. Be careful and do not use too much glue. Use a small amount of force to hold it together for a few minutes before testing the rotation. WD40 is advised. Future Development: I'm hoping this design can serve as a blue print for other standard bearing designs. I will try and make those as well. Additionally, the process of combining the two halves of the ball ring is difficult and can ruin everything. I'd like to come up with a better way that does not involve tiny unprintable features, at least for an Ender or other entry level models. Slicing Notes: I recommend printing everything with quality in mind. Additionally, you might want to disable or at least modify your retraction settings for the ball rings. Assembly Notes: There is likely some degree of variation in the diameter of the spool peg and ID of the spool itself. Due to this, you will have to aggressively sand the peg to make it smooth. Additionally, you will have to cut off the lip at the far end, not the end that affixes to the printer. You want the fit between the inner ring and peg to be snug but not so tight that you can't take it off. You will also want to sand every area of the rings that you can in order to make them as smooth as possible. After the glue is dry a spritz of WD40 is advised.