I've been 3D printing now for a few years and have collected countless spools of filament. I have my lab/shop in the basement and my joists are exposed. I decided to create this little hanger so I can use cheap 1/2" PVC pipe to hand my spools and other things from the joists. I just use some simple screws and cut a piece of PVC long enough to span the gap.

I designed it with two screw holes so if you are hanging something pretty heavy you can double up on the screws. Normally, you just use the center hole.

Works great.