Bambu Lab P1S AMS setup: mount, load, and print
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The Bambu Lab P1S with its AMS is the four-spool system I run, and it is still the one we would buy for a first multi-color printer. Setup takes about an hour: mount the AMS on top of the enclosure, connect the PTFE tube and the AMS bus cable, load four spools, and let the printer handle the rest. Prices checked October 2026. This guide is for anyone who has a P1S or P1S AMS Combo and wants the AMS working without the cardboard-spool jams and humidity failures that fill the owner forums. My P1S guidance comes from the unit on my desk; where we mention other spools, dryers, or hubs, the take is research-driven, built from spec sheets, teardown reviews, and owner reports.
| Role | Product | Why |
|---|---|---|
| Pick | Bambu Lab P1S | The owned combo this walkthrough is built on, start to finish |
Verdict and what to have on the bench first
The short answer: the P1S AMS Combo is a one-evening job if you update first and connect the AMS second, not the other way around. The P1S AMS Combo is $479 on the Bambu US store (typical price $549); the P1S AMS 2 Pro Combo is $509 (typical price $579).
In my box: the printer with the textured PEI plate installed, the AMS, the AMS bus cable, a length of PTFE tube, the top spool holder, a power cord, a hex key set, a scraper, a packet of grease, and a short sample of Bambu PLA. The three transport screws under the bed come out with the included hex key. The one tool not in the box that I reached for in the first hour was a pair of flush cutters for a clean 45-degree filament tip; a frayed end is the most common first-load failure in the AMS.
Before plugging in the AMS cable, run the printer alone: join Wi-Fi from the touchscreen, let it pull firmware 01.10.00.00, and install Bambu Studio 2.8.2.61 (the public release; 2.8.4 is in public beta) on the laptop. Owner reports describe a Studio build older than the printer firmware failing to send multi-color jobs, and that mismatch looks like a broken AMS when it is not.
Get this if you want four-color printing working tonight without a parts order. Skip this if you plan to feed one spool; the plain P1S is the same printer at $349 on the Bambu US store (typical price $399).
Bambu Lab P1S: mounting the AMS and routing the PTFE tube
The AMS lives on the P1S's top glass, and the four rubber feet land on the glass itself, not the frame. I set it slightly off-center the first time, so the lid rattled whenever the gantry moved fast. Centered, it sits still.
Two things run off the back of the AMS. The AMS cable plugs into the dedicated port on the rear panel, next to the filament inlet; it only seats one way, so if it won't click, flip it. The PTFE tube goes from the AMS outlet into the buffer, which screws to the rear panel, and a second short tube runs from the buffer into the printer's filament inlet. The buffer is not optional; it absorbs the slack when the extruder pulls faster than the AMS feeds.
My first mistake was cutting the tube too short between AMS and buffer. A tight bend adds drag and the AMS throws retry errors on retraction. Leave a loose arc with a little slack, and never loop it.
You need some clearance behind the printer for the buffer and tube arc. Mine was against a wall and kinked. The desiccant tray ships empty: slide it out, fill it, and check it monthly.
Get this if you want multi-color or silent spool swaps on a P1S.
Skip this if the printer must sit flush against a wall.
Loading spools and setting filament profiles
Push each filament into one of the four AMS slots until the feed gear grabs it and pulls the rest in; the slot shows as loaded on the printer screen once the sensor sees filament. On my P1S, the gear takes about an inch of straight, freshly cut filament, and a frayed or hooked end is the usual reason a slot stays empty. Bambu's own spools carry an RFID tag, and owner reports agree the AMS reads type and color within a few seconds, so those slots populate themselves in Bambu Studio. Anything else is manual: tap the slot on the printer screen or in Bambu Handy, pick the brand and material, set the color, and save. Choose the generic profile for the correct material rather than a near-match brand; the temperature range is what the slicer actually uses.
Cardboard spools are the standing caveat. The AMS rollers were designed for plastic hubs, and worn cardboard sheds dust that teardown reviews show collecting in the feed path. Bambu publishes printable spool-edge rings as a workaround. Keep TPU, soft PETG blends, and any brittle or abrasive filament out of the AMS and run them through the external spool holder instead.
Get this if you want multi-material prints without babysitting spool swaps. Skip this if your filament library is mostly flexible or cardboard-spooled.
Setting up a multi-color print in Bambu Studio
Import the model with File > Import, or drag the files in. If it's a multi-part STL set, Bambu Studio asks whether to treat them as one object with multiple parts; say yes so they stay aligned on the plate. A 3MF from MakerWorld usually arrives with parts and colors already assigned.
Assign colors one of two ways. For separate parts, right-click each in the object list and set its filament number. For a single body, use the Color Painting tool (hotkey N) and bucket-fill or brush faces. Keep the filament count in the slicer matched to what's physically loaded; owner reports are consistent that every extra filament adds purge and tower volume.
Click Slice, then Print Plate. The send dialog shows each slicer filament on the left and a dropdown of AMS slots on the right. Hit the refresh icon first so the dialog reads the AMS's current state from the P1S; if a slot shows "?" the RFID read failed and I set the type manually in the Device tab before sending. Studio warns on type mismatches but not on color mismatches, so check both.
Before confirming, read the filament usage line under the preview. It splits model, flush, and tower grams per filament. On my P1S a four-color coaster has sent a noticeable share of its filament to flush and tower; I reorder colors or raise the flush multiplier only when a part shows bleed.
Get this if you want per-object color assignment and slot mapping that takes under a minute once the AMS is loaded.
Skip this if your models are single-color and you'd rather keep a direct spool holder and no purge waste.
Managing purge waste: flush volumes, prime tower, and the chute
Every AMS swap on my P1S costs filament twice: the old color has to be cut and backed out, and the new one has to be pushed through until the nozzle runs clean. Bambu Studio decides how much to purge from a flushing volumes matrix, generated from how different the two colors are. Dark-to-light transitions get the largest numbers, light-to-dark the smallest. The flush multiplier defaults to 1.0; owners commonly drop it to 0.6 on jobs where the color change is on infill or a hidden face and keep it at 1.0 only for white after black or red. You can also edit single cells in the matrix for pairs you know are forgiving.
The prime tower is a sacrificial block printed every layer where the nozzle stabilizes after a swap, so the first line on the actual part is clean. Keep it. What you can shrink is the purge that lands in the chute: under Others, "Flush into objects' infill" and "Flush into this object" route transition filament into infill or into a part whose color does not matter, like a base.
The change filament G-code in the printer profile handles cut, retract, load, and purge. I have left it stock; edits there are where people make the wiper smear.
The chute drops poop out the back left. Owners typically keep a cardboard box there and a printed deflector so it does not pile against the glass.
Get this if you print multi-color and want to understand where the filament goes. Skip this if you only use the AMS as a four-slot filament changer.
Which AMS to add next: AMS, AMS 2 Pro, AMS HT, and AMS Hub
The cheapest four more slots for my P1S are a second original AMS; everything else costs more and solves a narrower problem.
A second original AMS is $199 on the Bambu US store (typical price $249) and behaves exactly like the first one, which is the point: same spool size limits, same passive desiccant, no surprises in Bambu Studio.
The AMS 2 Pro is $229 on the Bambu US store (typical price $299) and adds active heating, which Bambu rates to 65°C. Owner reports and teardown reviews describe it as a four-slot AMS with a heater and fan, not a redesign. The caveat for P1S buyers: drying works on the P1 series after a firmware update, but check the current compatibility notes before you assume the drying-while-printing mode is available.
The AMS HT is a single-spool unit at $119 on the Bambu US store (typical price $139), rated to 85°C, aimed at the nylons and PC blends that need serious drying. It handles Bambu's "TPU for AMS" and has a bypass outlet for generic TPU, though TPU loses automatic feed and retract through it. One slot is the whole proposition.
The AMS Hub is $48.99 on the Bambu US store, and you need it: the P1S only has one AMS port, so a second unit of any kind requires the hub, which supports up to four units and 16 slots total.
Get this if you have already outgrown four slots and know which spools are stalling you. Skip this if you have not yet filled the first AMS with filament you actually print.
Problems you will hit and how I fixed them
The buffer is where most of my jams happened. The small unit on the back of the P1S lets the AMS feed slack to the toolhead, and a filament end with a burr or a sharp 45-degree cut angled the wrong way catches inside it. My fix is boring: cut a clean, straight end before loading, and if it does stick, unload from the slot, unclip the PTFE tube at the buffer, and pull the filament out by hand instead of forcing a retry.
A slot that will not detect a spool is almost always the feed wheel slipping on scuffed filament. Trimming an inch off the end solved it every time. RFID detection only works with Bambu spools; everything else needs the type and color set by hand in Bambu Studio.
Tangle alarms came from loose third-party spools, not from the AMS itself. I rewind by hand and avoid cardboard spools, which slip on the rollers.
The included desiccant lasts a few weeks in a New England summer. I swapped in refillable canisters and watch the humidity reading in Bambu Handy; once the reading climbs, the packs are spent.
Backup spools: load two slots with the same type and color, then turn on auto refill in the AMS settings. Prints keep going when one runs out.
Get this if you print multicolor or run long jobs unattended.
Skip this if you mostly print TPU, which the AMS cannot feed.
How we chose
I run a Bambu Lab P1S on my own desk, and everything in this guide about the printer side, the rear PTFE routing, the spool holder, and the firmware prompts comes from that machine and the time I have spent running it. The AMS itself, the AMS 2 Pro, and the AMS HT are covered as research-driven picks: we worked from Bambu Lab's spec sheets and wiki, owner reports on the Bambu forum and r/BambuLab, and teardown reviews of the first-generation AMS feed motors and hub. We weighed four things: compatibility with the P1S (the AMS Lite is excluded because it does not connect to the P1S), hub and buffer failure reports, filament types each unit will actually feed without grinding, and the real cost of the AMS plus the bowden tubes, desiccant, and spool adapters that owners end up buying anyway.
Bottom line
If you own a P1S and print in more than one color or material, the AMS is the upgrade I would buy again. By owner accounts it mounts in a few minutes, loads four spools without tools, and switching filaments mid-print is reliable once the PTFE tube lengths are set correctly. Buy it as the P1S AMS Combo ($479 on the Bambu US store, typical price $549) rather than adding the AMS later; the bundle is cheaper than the two parts bought separately.
The caveat is waste and compatibility. Every color change purges filament into the chute, so a four-color print can burn a large share of extra material. The AMS also will not feed TPU or other flexible filaments; those still go through the external spool holder. If you print single-color PLA, skip it.
Frequently asked questions
Does the P1S need the AMS Hub to run a second AMS?
Yes once you go past one unit. The P1S has a single AMS port on the back, and Bambu's own compatibility notes route a second, third, or fourth AMS through the AMS Hub rather than daisy-chaining from the first unit. The hub also lets an AMS HT or the external spool share the same system. One AMS alone plugs straight in.
How much filament does a multi-color print waste?
More than beginners expect. Every color change flushes the old filament out of the hotend, and the default flush volumes in Bambu Studio are conservative, so a four-color print with hundreds of layer changes can purge more grams than it prints. Lowering flush volumes for similar colors, enabling the prime tower, and choosing designs with fewer swaps per layer cut it hard.
Can the P1S AMS run TPU or cardboard spools?
Standard TPU is a no: the AMS feed gears can bind soft filament, so Bambu routes TPU through the external spool holder instead. Cardboard spools work but shed dust into the feeder, so plastic spool adapters are worth the few dollars. The AMS HT handles Bambu's "TPU for AMS" and offers a bypass outlet for generic TPU, though TPU loses automatic feed and retract through it, which is a reason to add it later.
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Edited by Adam Ryan. Gear picks come from equipment running in his own homelab and workshop. Software picks are researched comparisons.
