What do you do with empty spools?

Title says it all. What do you do with your empty spools? Send them back in, throw them away, something else?

You could resell them or donate them to someone with a filament extruder.

or get a filament extruder and recycle them yourself...

I have been buying bulk filament (no spool) and rewinding it onto my old spools. This saves money and for some reason my supplier always seems to be out of the color I want on a spool but has it without a spool.

You can of course also put them into the recycle bin.

How do you wind the bulk filament? Do you do it by hand, use a power drill, or one of the winders?

I do it by hand but should find a better method. I hang the bag of filament on a swivel with a hole in the center of the bag I feed the filament to the spool then just spin the spool, the bag spins also and this prevents tangling and undue tension on the filament. I have only done this a few times (tried other methods that failed and caused tangled and knotted filament). It would probably be easy to build some sort of winder for the reel itself. I may just work on this and save money on filament.

Hello!

Where do you buy bulk filament? I'm new to 3d-printing and need to get a lot of filament in a few months.

Have you tried the things used to unwinding yarn? My mother has left one (or two) for me and my daughter have some too.

By bulk I mean in bags no spools. I buy most of mine from Ultimachine that has it in 1lb and 5lb bags.

I went ahead and designed a winding machine tonight and it's printing now. Assuming it works I will post it on Thingiverse. It's just 2 main parts, a spool holder (bearings) and a hand crank that slides into the type of spools I use (like those sold on Ultimachine and Lulzbot). You hang the bag as I mentioned earlier, start it onto a spool, and crank the handle. Should be able to fill a spool in a few minutes. I am sure it will take practice to get it right but should be worth it.