Updated October 2026. Bambu Lab now sells four material systems, and each has its own idea of what a spool should look like. Here is the spool size each one takes, what that means for the rolls we sell, and the two-minute fix for the ones that do not fit on their own.
The spool sizes, unit by unit
| Unit | Printers | Spool width | Spool diameter | Drying | Notes |
|---|---|---|---|---|---|
| AMS (original) | X1 Carbon, X1E, P1S, P1P | 50 to 68 mm | 197 to 202 mm | None (desiccant only) | Four slots; up to four units through the AMS Hub for 16 colours. Enclosed box with rollers that expect smooth, rigid spool edges. |
| AMS 2 Pro | X1, P1, H2 series; A1 series after a firmware update | 50 to 68 mm | 197 to 202 mm | Active, up to 65°C | Same spool envelope as the original AMS. Up to four AMS 2 Pro plus eight AMS HT in series, 24 filaments. |
| AMS Lite | A1, A1 mini | 40 to 68 mm | Hub (centre hole) 53 to 58 mm | None | Open frame; spools sit on external rollers. One unit per printer. The most forgiving of the four on spool shape. |
| AMS HT | X1, P1, H2 series (A1 support via update) | 50 to 68 mm | 197 to 202 mm | Active, up to 85°C | Single spool, sealed, built for materials that need hot drying: PA, PC, ASA, PET and the carbon fibre blends. |
Every unit takes 1.75 mm filament only. The numbers above are Bambu Lab's published ranges; a spool that is a millimetre or two outside them often still works, but it is a gamble, and a spool that is too wide for the lid or too soft at the edge is where most AMS feed problems start.
What that means for our rolls
Select matte, silk and PETG: drop straight in
Select ships on a rigid 1 kg plastic spool sized for the AMS envelope. It loads into the AMS, AMS 2 Pro, AMS Lite and AMS HT with nothing printed and nothing rewound, which is the reason the line exists. Matte and silk PLA are $16.99 a roll, PETG is $14.99.
EconoFil on cardboard: print two rings
EconoFil PLA and PETG come on a cardboard spool. Cardboard edges are slightly soft and can shed fibres onto the AMS rollers, so in the enclosed units (AMS, AMS 2 Pro, AMS HT) we recommend a pair of printed adapter rings. They take about 15 minutes each, snap onto the spool rim, are reusable, and the full walkthrough with the file we recommend is in how to use cardboard spools in your Bambu printer. On the open-frame AMS Lite many people run cardboard as-is; the rings still keep the edges from wearing. Where a colour is offered on a plastic spool, that option goes straight in like Select.
Hyper PLA
Hyper PLA is made for the speeds the Bambu printers run at, and it ships on the same cardboard spool as EconoFil, so it takes the same two rings in an enclosed AMS. The rings are reusable: one pair serves every cardboard roll you buy from us.
TPU and flexibles: external spool holder
Our Filaments.ca TPU (Shore 91A) and NinjaTek Cheetah are too soft for the AMS feed path; Bambu Lab's own guidance is to run generic TPU from the external spool holder through the bypass. The spool size does not matter there.
Carbon fibre blends
Abrasive filament such as our carbon fibre PETG wears the PTFE tubes and feed gears faster than plain PETG. The AMS HT is built for it; in the other units Bambu Lab steers generic fibre-filled filament to the external holder as well. Either way use a hardened nozzle.
Quick checks before you load a new spool
- Width. Measure flange to flange. Over 68 mm and the lid will not close on the AMS or AMS 2 Pro.
- Diameter. A 1 kg spool between 197 and 202 mm sits properly on the rollers. Smaller 500 g spools (often 40 mm wide or under 180 mm across) need the AMS Lite or a printed adapter.
- Edge. Smooth and rigid feeds reliably; cardboard or a cracked flange needs rings or the external holder.
- Dry it first. The original AMS and AMS Lite do not dry filament. PETG, TPU and ASA that have been open for a few weeks print better after a few hours in a dryer, and the AMS 2 Pro and AMS HT can do it in place.
- Odd spool? Transfer it. Bambu Lab sells empty reusable spools, and the community has printed refill-spool adapters for most brands; rewinding a refill coil onto one takes ten minutes.
Settings once it is loaded
Our PLA runs 190 to 210°C on a 45 to 60°C bed in Bambu Studio's generic PLA profile; Hyper PLA 200 to 230°C at the fast profiles; PETG 220 to 260°C on a 75 to 85°C bed with cooling turned down. Full numbers, plate by plate, are in the temperature guide. Questions about a specific roll: hello@filaments.ca or 1-844-465-7684, Monday to Friday.
Bambu Lab, AMS, AMS Lite, AMS 2 Pro and AMS HT are trademarks of Bambu Lab. Filaments.ca is not affiliated with Bambu Lab; specifications are from Bambu Lab's published product pages and wiki as of October 2026 and may change.