Modular hanging spool holder

My approach to this problem, I have limited space and I want to utilize it as much as possible. For me, this was a decision to hang filaments under the shelf rather than put them on the shelf.

At the bottom, I've written a summary after months of using those hooks if you are interested it's worth implementing this system.

Design

This hook is designed for poles with 22mm* diameter, simply because I found such wooden poles in my hardware store. It should work with thinner ones. This design solves a few issues I had with others I found available here or on Thingiverse. 

For the 1-inch poles version check the remix made by @Pip Arnes, the remix is only for hooks, modular poles will work with both versions

No sagging

Some of the designs are complete solutions that allow you to print hook and filament pole as a single element, while this makes printing easier the main problem with this design is its sagging, it is often mentioned by authors to just print a new one if the old one is bent too much.

This one is very rigid, with extra webbings added to reinforce it more, and IMO makes it look more interesting. Webbings are a bit random since I don't have a lot of experience with them.

Modular

You might find some other similar designs to this one but they usually assume you will hang a single spool, while I don't mind that I would like to hang as many spools as possible, because of that the hole has an extra lip on both sides, see picture

This allows using printed filament poles on both ends. Not only that, the single hook can handle two printed poles at once meaning you can use 3 hooks and 2 printed poles to hang 2 spools, while other designs will force you to print 2 hooks for each spool you want to hang. Here you can easily hang your spools in series.

Easy to use

Does not require any screws, you slip the printed pole into the hooks and you are done. Even if you use it for a single spool it is secured properly.

Printing

Small tips

Hook

Doesn't require supports, bridging is minimal and I printed it with a standard Prusa 0.2 speed profile without any issues. However, during the printing of the mid-layer, you may observe small gaps near the webbings, don't be alarmed those will be properly covered, I've printed 6 of those hooks and they all look fine.

Printed filament pole

Doesn't require supports, I would recommend 5% gyroid infill as it does not require more to handle the spool.

Concerns

Keep in mind, I already printed some stuff while using those hangers and I had 0 issues so far with them, but I will still share some of my concerns.

Printed poles - could be designed better, they won't rotate much while being used but still but I hoped they won't rotate at all, still, they work fine. Also, printed poles might feel like they add more friction than standard non-printed poles/hangers, I didn't see any issues with printing but there is a slight risk that some extruders might not handle it well, the solution would be to print with thinner layers (0.1 or less) or maybe sand them.

Hooks in series - I've seen that ‘connected’ spools tend to swing together, I'm not sure if that will be the issue, the more spools the higher the mass the more stable it will be, but with 2 spools swinging was possible.

Update, after months of using

I used those a bit before uploading my designs but I was still a bit unsure if this solution would be fine after months of using it. But it is, as hoped

• The hooks are not sagging, not visibly at least, this is nice
• Switching filaments is not effortless, it's not that complicated either but requires a bit of precision, I don't know how it could be improved, on the other hand, I don't switch my spools that often and still I can switch single spool instead of taking down the whole pole to replace empty spool in the middle of the pole with a new one
• Printed spool poles, the one between two hooks, could be smoother but I have never had any issues while printing, a standard MK3S+ extruder can handle them no matter if it's pulling from the middle of the pole or the side of it

In summary, I'm happy with the system, for me, it simply works, and it solves all my issues. Also, I don't feel that it requires improvements, sure, it could be improved but I don't struggle with it enough to be bothered by very small issues it has.