When I first started out with 3D printing, I had like one or two spools of filament. I would mount one on the printer’s built-in spool holder and the other would lay around somewhere. As I started experimenting with different materials and colors, I accumulated quite a few spools that would lay on top of each other, looking like a leaning tower of filament. Every time I wanted to replace filament, I had to play filament Jenga, pulling the one I wanted from the stack without making the tower collapse on top of my expensive speakers.
It looked bad, it was dangerous and uncomfortable, it was time for change. The first thing that came to my mind was “Someone must have had this problem before me. There’s probably a model ready for download on Thingiverse”, but all I found were single spool holders or more complex racks with spools mounted on bearings or on the wall. I wanted something simple, so I made one myself.
I had a spare metal broomstick laying around that was perfect for the job. It’s light but strong enough to carry the weight and it’s cheap enough so I wouldn’t care re-purposing it. I designed the model in SketchUp, I wanted to make it quick and keep it simple so I didn’t need any super-advanced tools. The model is just a clamp on triangular legs. The clamp attaches to the broomstick, obviously, and the triangular legs prevent the whole thing from tipping over. I added some braces inside the legs to provide structural integrity. I wanted both sides to be identical so I could just model one side and print it twice (instead of having to model a different piece for each side).
There are some guidelines and limitations that I had to follow in order to make this function as I want: The diameter of the broomstick is ~21.5mm. In order for the clamp to work, it had to be slightly smaller that value in it’s closed position and slightly larger when it’s open. The clamp needs to be high enough for the spools to clear the bottom, taking into consideration that the top of the spool’s hole sits on top of the broomstick rather than them being coaxial (I might add an attachment to the spools to make them coaxial and maybe reduce friction) The base needs to be wide enough for the rack to be stable and not tip over by the force of the extruder and external accidental forces. I’m not too concerned about friction and the force applied bu the extruder’s pull because the broomstick I chose is laminated and the spools slide on it very easily. The gap of the clamp needs to be big enough to work but not too bit or the plastic might break or its layers separate. The clamp levers need to be long enough to accommodate the screw head and nut and thick enough so they don’t break under pressure.
Print settings: Material: red PLA
Temperature: 190 deg C
Layer height: 0.3 mm
Print Time: ~80 mins per side
Slicing and interfacing program: Simplify3D
Printer type: Prusa i3
The model is available on Thingiverse along with the original file so people could make changes if they want.