Installing a Filament Buffer on the Bambu Lab P2S (And Avoiding a Very Specific Kind of Pain)

Installing a Filament Buffer on the Bambu Lab P2S (And Avoiding a Very Specific Kind of Pain)

If you’ve ever confidently ordered a 3D printer accessory thinking, “I already have this—no problem,” this article is for you.

This guide walks through installing the correct filament buffer on the Bambu Lab P2S, adding an AMS, and—most importantly—explains why the old X1C filament buffer doesn’t fit, even though everything looks compatible on paper.

Spoiler: it’s not you. Accessories evolve.

The Mistake That Started It All

The original plan was simple:

Unbox the Bambu Lab P2S, set it up, compare it to the X1C, and move on with life.

Then chaos.

While installing the printer, I discovered that the filament buffer from the X1C physically does not fit the back of the P2S. Same job. Same concept. Completely different shape.

Yes, I stared at it for a solid minute, hoping belief alone would make it fit.

It did not.

Why the X1C Filament Buffer Doesn’t Work on the P2S

Even though:

  • The P2S and X1C both support the original AMS

  • The AMS itself hasn’t changed

  • Everything sounds interchangeable…

Bambu Lab quietly updated the filament buffer design.

The Important Part

  • Old buffer (X1C): SA-011 → ❌ does NOT fit

  • New buffer (P2S): SA-001 → ✅ required

If you buy the P2S without the combo, the correct filament buffer is mandatory for AMS use.

Two perfectly good filament buffers now live permanently as shop decor.

The Worst Part: Inventory Limbo

When I realized the issue, the new filament buffer was out of stock for 3–4 weeks.

So there it sat:

  • Fully assembled

  • Fully capable

  • Trapped in single-color mode, like it was being punished for something it didn’t do

When it finally came back in stock, I ordered it immediately… and yes, it promptly went out of stock again.

Do You Need a New Six-Pin Cable?

According to the P2S listing, you also need:

  • Six-pin cable: CAB-035

Here’s the good news:

  • The original AMS six-pin cable still works

  • Pins did not change

I ordered the cable anyway because the shipping cost weighed less than the emotional damage of not having it.

Installing the Filament Buffer on the P2S

Installing the new filament buffer is refreshingly simple.

Basic Steps

  1. Remove the rubber cover on the back of the P2S

  2. Locate the internal connector (already tucked inside)

  3. Connect the filament buffer cable

  4. Slide the buffer into the mounting groove

  5. Secure it with the two screws

No printer disassembly. No stress.

Connecting the AMS Properly

PTFE Tube Setup

  • One tube from the AMS into the filament buffer

  • One longer tube from the buffer into the printer

  • Lock clips back into place

Cable Connection

  • Use the existing six-pin AMS cable

  • Plug it in and power on

If everything is connected correctly, the printer should recognize the AMS immediately.

Firmware Update (Don’t Skip This)

On the first print attempt, the AMS colors didn’t update correctly.

The reason?

The AMS firmware and printer firmware were on different versions.

Once updated:

  • Colors synced instantly in Bambu Lab Studio

  • AMS functioned perfectly

This level of hardware-to-software communication was genuinely impressive.

First Multi-Color Print Results

After updates:

  • Original AMS worked

  • Original six-pin cable worked

  • Only the filament buffer needed replacing

Four colors loaded.

First print completed cleanly.

Gelatinous cube maker approved.

The Takeaway

Even when printers are compatible, accessories evolve.

Sometimes the only thing standing between you and multi-color printing is:

  • A small piece of plastic

  • A cable

  • Or waiting for inventory to exist again

Once installed?

Totally worth it.

Original Bambu Lab P2S Video: https://www.youtube.com/watch?v=rpT192UX1_c

🛠 Help Support the Channel (Affiliate Links)
• 3D Printers - https://amzn.to/44A971y
• PLA filament - https://amzn.to/4p4OJNk

 🧰 Tools & Gear
📌 Bambu Lab P2S - https://bambulab.com/en-us/p2s
📌 Bambu Lab AMS - https://us.store.bambulab.com/products/ams-2-pro
📌 P2S Filament Buffer (SA-001) - https://us.store.bambulab.com/products/filament-buffer-p2s
📌 Bambu Lab 6-Pin Cable - https://us.store.bambulab.com/products/bambu-bus-cable-6pin-for-ams-2-pro-and-ams-ht

Final Advice (Learn From My Pain)

  • ✔ Read combo vs non-combo listings carefully

  • ✔ Verify exact accessory model numbers

  • ✔ Assume “compatible” doesn’t mean “physically identical”

Keep on making.

And remember:

Measure twice. Order once. Upgrade anyway.

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