Written by Danielle Arnold
Quick answer: Our standard 1 kg rolls are listed at 200 mm across and 65 mm wide, within the spool limits for the AMS, AMS 2 Pro and AMS HT. Set each slot's filament manually, as Bambu requires for non-Bambu spools, print with a preset based on Bambu's Generic profile, and keep TPU and fibre-filled filament out of the feeder.
Bambu Lab's Automatic Material System (AMS) is built around Bambu filament, but it runs third-party filament well when three things are right: the spool fits, the material suits the feeder, and the printer knows what is loaded. This guide covers all four AMS units, the spool sizes listed on our product pages, how to set up a custom filament preset and calibrate it, drying in the AMS 2 Pro and AMS HT, and the materials that should bypass the AMS.
Everything below about the AMS comes from Bambu Lab's own documentation and published specifications, which we checked in September 2026. Bambu updates its firmware and specifications regularly, so follow the links to confirm details for your unit.
The four AMS units compared
| Unit | Spool size supported | Built-in drying | TPU and fibre-filled filament |
|---|---|---|---|
| AMS | 50–68 mm wide, 197–202 mm diameter | No | Avoid TPU, TPE, damp PVA and hard or brittle fibre-filled filament |
| AMS lite (A1 series) | 40–68 mm wide, 53–58 mm inner diameter | No | Avoid TPU, TPE, damp PVA and third-party fibre-reinforced filament |
| AMS 2 Pro | 50–68 mm wide, 197–202 mm diameter | Up to 65°C | Generic TPU and fibre-filled filament not supported, except Bambu PLA-CF, PAHT-CF and PETG-CF |
| AMS HT | 50–68 mm wide, 197–202 mm diameter | Up to 85°C | Bypass outlet for TPE, generic TPU and fibre-filled filament |
Sources: Bambu's notes for AMS, the AMS lite FAQ, and the published specifications and FAQ for the AMS 2 Pro and AMS HT.
Will OzFDM spools fit?
Most filament product pages list the spool in the Product Specifications section. For our standard 1 kg rolls they list a 200 mm outer diameter, a 52 mm hub, a 65 mm width and an empty spool weight of 150 g. That sits inside the 197–202 mm diameter and 50–68 mm width range Bambu gives for the AMS, AMS 2 Pro and AMS HT.
The AMS lite on the A1 series mounts each spool on a hub, and Bambu specifies an inner diameter of 53–58 mm. Our listed 52 mm hub is just under that range, so check that the spool seats and turns freely before you start a long multicolour job.
A few products differ, so check the product page before you buy for an AMS:
- PVA Support Filament (0.5 kg): the spool is listed at 180 mm diameter and 49 mm wide, below the AMS minimums. The product page recommends a small spool adapter, and Bambu only supports PVA in the AMS 2 Pro and AMS HT when it is dry.
- PETG 2.5 kg: the product page says this larger spool exceeds the AMS size limits. Run it from an external spool holder.
- PLA Basic and PETG Basic: these product pages recommend moving the filament onto an AMS-compatible reusable spool for the most reliable feeding. Our PLA+ page describes a 200 mm AMS-compatible spool with thicker 2.5 mm walls, and the Matte PLA and several speciality PLA pages also describe 200 mm AMS-compatible spools.
Our product pages do not state the spool material. If that matters for your setup, ask us before you order.
Cardboard spools
Bambu recommends plastic spools that fit correctly inside the AMS. If you use cardboard spools from any brand, Bambu strongly advises fitting a spool adapter ring to reduce slippage and cardboard debris. You can print one, such as this parametric cardboard spool adapter ring, or wind the filament onto a reusable plastic spool.
RFID: tell the AMS what is loaded
The AMS 2 Pro and AMS HT read RFID tags on official Bambu Lab filament, which is what enables features such as remaining filament estimates and automatic backup. For any other spool, including ours, Bambu says you need to configure the filament information yourself, either on the printer screen or in Bambu Studio.
- Set the material type and colour for the slot as soon as you load the spool.
- The slot keeps the previous details the next time you insert an untagged spool, so update them whenever you swap filament.
- You cannot edit the filament information while a print is running, so set it before you start.
Build a custom filament preset in Bambu Studio
If your printer and material are covered in our print profiles, start with those settings. Otherwise, build a preset in four steps.
1. Start from the Generic profile
Bambu Studio includes Generic presets for each material type, such as Generic PLA, Generic PETG and Generic ASA. Choose the one that matches your filament rather than a Bambu-branded preset, which is tuned for Bambu's own filament. Open the filament settings from the Prepare tab.
2. Set temperatures from the product page
Copy the nozzle and bed temperatures from the Print Parameters section of the product page, or from the PDF data sheet where the product page has one. For example, our PLA+ page lists a nozzle range of 190–220°C and PETG+ lists 210–230°C. Start in the middle of the range, then save the preset under a clear name such as "OzFDM PETG+ Black". Our guide to managing print profiles covers naming and backups.
3. Run flow dynamics calibration
Bambu calls pressure advance "flow dynamics". Bambu Studio's flow dynamics calibration has automatic and manual modes, depending on your printer. Bambu recommends recalibrating for a new filament brand or type, a new or worn nozzle, damp filament, or a change in print temperature or maximum volumetric speed. Results are saved with a name, and you choose the K value for each AMS slot in the material settings on the Device page. For the theory, see our pressure advance guide.
4. Run flow rate calibration
Do this after flow dynamics. Bambu's flow rate calibration prints a coarse set of blocks in 5% steps, then a fine set in 1% steps. Pick the block with the smoothest top surface and save that flow value to your filament preset. Our flow rate calibration guide explains what the number is doing.
When you slice, select your custom preset for each filament in the project, then map each one to the AMS slot holding that spool when you send the print.
Drying in the AMS 2 Pro and AMS HT
The AMS 2 Pro reaches a maximum drying temperature of 65°C and the AMS HT reaches 85°C. Compare those limits with the drying recommendation in the Product Specifications section of each OzFDM product page:
| OzFDM material | Drying recommendation on the product page | Reachable in AMS 2 Pro (65°C max)? | Reachable in AMS HT (85°C max)? |
|---|---|---|---|
| PLA+, Matte PLA, Silk PLA | 40–45°C for 4–6 hours | Yes | Yes |
| PLA Basic | 50°C for 5 hours | Yes | Yes |
| PETG+, PETG Basic | 70°C for 5 hours | No | Yes |
| ABS+, ASA | 80°C for at least 5 hours | No | Yes |
| Polycarbonate, PA6 Nylon | 80°C for 12 hours or more | No | Yes |
| PPA-CF, PPS-CF | 120°C for at least 8 hours | No | No, use a filament dryer or oven |
Two points from Bambu's documentation are worth knowing. Do not load filament into the feeder while drying, and at the time of writing drying is not supported on a unit that is actively involved in a print. Dry first, then print. For storage between jobs, see our filament storage and drying guide.
Flexible and abrasive filaments
TPU and Flexible PLA
Bambu's TPU printing guide warns that TPU in the 80A to 95A hardness range can bend inside the AMS and cause feeding failures, and the AMS 2 Pro specification lists generic TPU and TPU 95A as unsupported. The AMS HT can hold a TPU spool and send it through its bypass outlet, but you load it manually because automatic feed and return do not work with TPU.
Our TPU95A and Flexible PLA product pages both advise against feeding them through the AMS, so load them from an external spool holder instead. Our guide to printing flexible filaments covers the settings.
Carbon fibre and glass fibre
Bambu's filament guide notes that some brands of fibre-filled filament are too brittle and break in the AMS channel, while others are hard and rough enough to damage it. Among fibre-filled filaments, the AMS 2 Pro supports only Bambu's own PLA-CF, PAHT-CF and PETG-CF, the AMS lite is not recommended for third-party fibre-reinforced filament, and the AMS HT sends fibre-filled filament through its bypass outlet.
Following Bambu's guidance, feed our PLA-CF, PETG-CF, ASA-CF, PC-CF, PA6-CF, PA12-CF, PET-CF, PPA-CF, PPS-CF and glass fibre grades from an external spool holder or the AMS HT bypass outlet, and use a hardened nozzle. Our hardened nozzle comparison explains the options.
Shop the materials in this guide
- 1.75 mm PLA+ Filament - 1 KG: supplied on a 200 mm AMS-compatible spool with 2.5 mm walls.
- 1.75 mm Matte PLA Filament - 1 KG: a low-sheen PLA supplied on a standard 200 mm AMS-compatible spool.
- Matte PLA Cool Tones Pack (Lavender, Turquoise, Slate Blue and Sea Green, 4 KG): four colours to fill a four-slot unit.
- 1.75 mm High Speed PLA Filament - 1 KG: the product page lists it as suitable for the AMS and AMS lite.
- 1.75 mm PETG+ Filament - 1 KG: tougher parts, best dried in an AMS HT or a separate dryer first.
- 1.75 mm ASA Filament - 1 KG: UV-resistant outdoor parts on an enclosed printer.
Frequently asked questions
Do I need Bambu filament for the AMS to work?
No. The AMS feeds third-party filament that fits its spool limits and suits the feeder. You set the material and colour for each slot yourself, and features that rely on Bambu's RFID tags, such as remaining filament estimates, are designed around Bambu's own spools.
Why does my AMS show the wrong filament after I swap spools?
Bambu's documentation says a slot keeps the previous filament details when you insert another untagged spool. Tap the slot on the printer screen, or edit it in Bambu Studio, and set the new material and colour before printing.
Will OzFDM spools fit the AMS lite on an A1?
The 65 mm width is within the AMS lite's 40–68 mm range. The listed 52 mm hub is just under Bambu's 53–58 mm inner diameter range, so test the fit and make sure the spool turns freely before a long print.
Can I dry PETG in the AMS 2 Pro?
Our PETG product pages recommend 70°C, which is above the AMS 2 Pro's 65°C maximum. Use an AMS HT or a separate filament dryer to reach the recommended temperature.
