How to use cardboard filament spools in your Bambu printer with one simple print.

We ship our filament on cardboard spools because the world doesn't need more plastic sitting in landfills. But if you own a Bambu Lab printer with an AMS, you've probably noticed that cardboard spools don't just drop in like Bambu's own plastic ones. The fix is simple: print a pair of adapter rings and you're done.

?Why cardboard spools need adapters

Bambu designed the AMS around their own plastic spools. The rollers inside expect smooth, rigid edges. Cardboard spools have slightly softer edges and can shed tiny fibres as they spin, which over time can gum up the roller mechanism. The adapter rings solve both problems: they give the AMS the smooth plastic surface it expects while keeping cardboard dust out of the works.

Without adapters, you might get away with it for a few spools. But you'll eventually notice the AMS struggling to rotate the spool, failed retractions, or cardboard residue building up inside. Adapters cost ten minutes of print time and save you a headache down the road.

1Download the adapter model

The community has designed dozens of adapter rings for different spool brands and sizes. For Filaments.ca spools, we recommend the Cardboard Spool Ring for Bambu Lab AMS by Blizzard on Printables. It's been tested with our spools specifically, has over 200 reviews, and comes in multiple versions if you need to fine-tune the fit. It's also parametric, so you can adjust it in Fusion 360 for any spool size.

Download the STL file. You'll need to print it twice, one ring for each side of the spool.

2Print two adapter rings

This is one of the easiest prints you'll ever do. Open the STL in Bambu Studio (or OrcaSlicer if that's your thing), and use these settings:

Each ring takes about 15 minutes and uses roughly 8–12g of filament. Print them both in one go and you'll have a pair ready in half an hour. Any colour works, this is a functional part, not a beauty contest.

3Snap the rings onto your spool

Once your rings are printed, press one onto each side of the cardboard spool. They're designed for a snug friction fit, you'll feel them click into place around the cardboard rim. The ring should sit flush against the spool face with no wobble.

A few tips to make this go smoothly:

• Push evenly around the circumference. Don't try to force one side in first. Work your way around the ring, pressing it on evenly so it seats flat.
• If it's too tight, check for humidity. Cardboard expands when it absorbs moisture. If your spool has been sitting in a humid room, the rings might feel impossibly tight. Toss the spool in a filament dryer for an hour and try again.
• If it's too loose, a small strip of tape fixes it. Wrap a thin strip of masking tape around the cardboard edge before pressing the ring on. This adds just enough thickness for a snug hold.
• The rings are reusable. When a spool runs out, pop the rings off and snap them onto your next one.

4Load it into your Bambu

With the adapter rings on, your cardboard spool now behaves exactly like a standard plastic spool. Drop it into the AMS slot, feed the filament through the feeder tube, and you're printing.

AMS (X1, P1 series)

The full-size AMS has a maximum spool width of 202mm with the lid closed. Our spools with adapters come in well under that limit. If your lid feels snug, there's an AMS Lid Riser available on MakerWorld that adds a few millimetres of clearance, but most people won't need it.

AMS Lite (A1, A1 Mini)

The AMS Lite uses a different mounting system, your spool sits on external rollers rather than inside an enclosed box. The same adapter rings work here. They keep the spool edges smooth so the rollers can grip properly and spin the spool without slipping.

External spool holder (no AMS)

As mentioned earlier, if you're running without an AMS, you don't need adapters at all. The spool sits freely on the holder and gravity does the work. But if you decide to add an AMS later, you'll already know the drill.

30 Minutes to Say Goodbye to Plastic Spools.

Thirty minutes of print time, two snap-on rings, and your Bambu AMS runs cardboard spools like they were made for it. The adapters are reusable across every spool you buy from us, so this is truly a one-time setup.

We chose cardboard spools because every kilogram of filament we sell shouldn't come with a chunk of plastic that outlives the thing you printed with it. These adapters are the bridge between doing the right thing and keeping your printer happy. Print a set, keep them in your AMS toolkit, and never think about it again.