What

This is a spool insert designed for BambuLab spools, but with the step files included it can be modified/remixed for other spools as well - which I encourage anyone with the skills to do. It essentially allows the filament to be put on both halves of the spool individually, all while maintaining AMS compatibility and functionality for the loaded filament. This project doesn't allow you to use more colors than AMS allows, just to “store” more different filaments in the AMS enclosure or anywhere else.

This is not limited to AMS, it should work with all kinds of rollers, spool holders, filament dryers, etc.

Why

I've accumulated many spools with a little bit of filament left (<500g), but it's usually in a color or material that I don't want to waste on some random thing, given that I don't have too much space to begin with, this is using a lot of space that I'd like to avoid. The smaller spools available for printing don't take a lot of space, but don't fit well in AMS, filament dryer, and so on.

At the same time, there are some materials and colors which I use to print all the time, these lead to empty spools that I reuse if possible, or throw out if I have no use (and no space) for them.

This made me to think if I can somehow solve, at least for me, both of these problems. And this is what I came up with.

How

The spool insert fits on the empty BambuLab Spools and allows you to put filament on one or both sides. Unlike a lot of “Sample spools” available, this one is compatible with the AMS out of the box, as it just uses the default spools.

Due to the added weight of the insert itself, of around 120g total, this also allows for smoother operation with the AMS as the spool doesn't end up being too light for it - this is also the reason why it's not just a simple thin disc in the middle.

The insert is easily removable, doesn't require glue, or any other tools. The additional pins hold the two halves together.

It has an integrated 1.75mm filament holder as well, to prevent filament from sticking out of the spool in any way.

Usage and hints

You can load up around 400-450g of the filament on each side. I generally recommend putting filament to the part where it's all solid all around the spool, however I've added even more than this to test it and I didn't have any issues.

For putting the filament on the roll itself, I've used an electric drill and a small adapter and did it manually, I haven't verified if this works with any of the dedicated projects for transferring filament from one spool to another.

For print settings, the default 0.2 layer height should work just fine. No supports, or any extra settings needed.

Small note: When loaded in AMS this means the change between the two filaments must be done manually, so I tend to put filaments that I know I'll never use in the same print, to avoid having to manually change the filament just because both sides need to be used in the print. For example, I load ABS on one side and PLA on the other, as the chance of using both of those in one print is low.