If you regularly use a 3d printer then you know the pain of empty spools. There are a couple manufacturers that do things such as cardboard spools which are much easier to recycle. However, the majority of manufacturers use plastic spools, which are more difficult to recycle and I feel bad just throwing them away. The maker inside of me wants to make something useful out of them, and I have a 3d printer, so you would think that should be possible!
Here is a list of just a few things you can do with those empty spools, in no particular order:
The spools intended use was to wrap stuff around it, that doesn’t have to change. Wrap Christmas lights around it for easy convenient storage and use next year. Wrap rope or string around it, basically anything that is rope like would be a good fit. This ensures that the thing wrapped around it will not get tangled, it’ll be much easier to use the next time you go to use it!
Make them into a shelf! On Thingiverse there is a piece that will connect two spools together, thus turning your old spools into a circular shelf. I wouldn’t stack these too high though. I know you have plenty of printed dust collectors that could fit on these shelves to display. I at least have enough benchys to fill up a few spools.
https://www.thingiverse.com/thing:1677024Use the spools as a paint holder/paint station. I do a lot of airbrushing, but I use acrylic paint for this. This has helped me a lot. I can store all the colors of paint I want in the spool and in the center of the spool I can put a cup of water which I need to water down the acrylic paint for airbrushing as well as cleaning in between color swaps. You don’t need to 3d print anything for this, just drill holes big enough for the paint in the spool, but you can 3d printing connectors to stack these on top of each other.
https://www.thingiverse.com/thing:1695214All of the uses of these empty spools seem to revolve around storage, and this is one is no different. You can print drawers that will fit inside the spool, then after sliding a rod to hold them in place they will open and close. Use it to store small tools, electronic pieces, screws, etc. You can also print out connections to stack these on top of each other. It is kind of like the shelves shown above, but with drawers instead of just being open-faced. There are a few of these up on Thingiverse, and these will need to change sizes based on the brand of filament spools you have, this may need customization to work with your specific empty spools. Although after printing this out you will almost have another empty spool to use!
https://www.thingiverse.com/thing:2103466
I hope this helps at least someone out there. It's time for me to start converting my 15 or so empty spools sitting in the corner into some useful things. I still haven't taken down all my Christmas lights, so there is my first step!