The Bambu Lab X1 Carbon and the Bambu Lab P1S are the two used Bambu printers people compare most. From across the room they look like the same machine, and in a lot of ways they are. Both are enclosed CoreXY printers with a 256 mm cube build volume, both take the same AMS multi-color units, and both pack and ship the same way. The differences are in the toolhead, the sensors and the screen. If you only print PLA and PETG, most of them won't touch you.
Where they came from
Bambu Lab was founded in Shenzhen in 2020 by four engineers from DJI, and the X1 series, launched in 2022, was its first printer. It was the flagship, with a lidar sensor on the toolhead and a hardened steel nozzle. The P1S followed in July 2023. Bambu kept the 256 mm CoreXY platform and the speed, and left out the X1's lidar and hardened nozzle. It replaced the X1's screen with a small 2.7-inch display and buttons. There's also an open-frame P1P, released in November 2022, which Bambu sells a kit to enclose, and an X1E with a heated chamber and Ethernet.
What's the same
The motion system is shared. Both are CoreXY printers with carbon X rods, and Bambu rates the P1S at up to 500 mm/s on the same platform. Both print on Bambu's textured PEI plates, both are enclosed, and both take up to four AMS 2 Pro or AMS HT units. Neither takes the AMS lite, which only works on Bambu's A-series printers. The maintenance is the same too. Bambu says to clean the carbon rods with isopropyl alcohol, never grease them, and to grease the Z lead screws every three months. And both pack the same way, with foam under the lowered bed, the toolhead wrapped, and the heatbed fixed with three screws.
Both run Bambu's firmware, with the authorization system Bambu added in January 2025, and both offer LAN Only and Developer Mode options for people who'd rather keep the printer off Bambu's cloud.
The nozzle
The X1 Carbon ships with a 0.4 mm hardened steel nozzle, and the box included a spare hotend. The P1S ships with a stainless steel nozzle, and Bambu's own spec sheet rates carbon-fiber and glass-fiber filaments as not recommended on it. If you want to print abrasive composites like carbon-fiber nylon or PETG, the X1 Carbon is ready for them. On a P1S you'd need to fit a hardened hotend first.
If you print PLA, PETG, TPU, ABS and ASA, the stainless nozzle is fine. Bambu lists all of those as ideal on the P1S.
Sensors and calibration
The X1 Carbon's micro lidar probes the nozzle height, calibrates flow and scans the first layer, and force sensors under the heatbed back it up. That means fewer failed first layers and less fiddling with flow. The P1S comes pre-levelled with automatic bed levelling, and it does the job well for most people, but it doesn't scan its own first layer.
The lidar comes in two production versions, and Bambu warns that a replacement lidar or toolhead board must match the printer's version, or the electronics can burn out. If a listing mentions a replaced lidar, ask which part was fitted.
Print hours
The X1 series shows its device usage time under Settings, then Device and Serial Number, so the printer tells you how hard it's been worked. Bambu's P1 screen guide lists no usage counter, so on a P1S you have to take the seller's word and judge from the nozzle, the plate and a recent print. Ask for that screen on any X1 Carbon.
Screen, camera and enclosure
The P1S has a 2.7-inch screen with buttons, which is enough to start and watch prints, though most owners use Bambu's apps. Its chamber camera is a basic 720p unit at 0.5 frames a second, good for time-lapses and checking on a print. Its enclosure is a plastic and glass shell with an activated-carbon filter.
Neither can become an X1E later. Bambu says X1 Carbon and P1 printers can't be fitted with the X1E's chamber heater, wired network module or hotend.
Which to buy
Buy the P1S if you print everyday plastics and want the most printer for your money. It's the same fast, enclosed CoreXY platform, and the sensors you give up mostly save you time rather than change what you can print.
Buy the X1 Carbon if you'll print carbon-fiber or glass-fiber filaments, want the lidar's first-layer checks, or want a printer that records its own hours so you can see what you're buying. A used X1 Carbon with low usage time and its spare hotend still in the box is a strong buy.
If the P1P tempts you, it's the same platform with an open frame. Bambu's official enclosure kit adds glass, side panels and a door, and from P1 firmware 01.05.00.00 an upgraded P1P can be marked as upgraded so it prints with P1S profiles. A P1P with the kit fitted is close to a P1S.
Either way, look at the AMS. Both were sold as Combos with the AMS, and an AMS in good order adds a lot. A Combo listing should show the AMS, its buffer and its cable.
What to check on either
- A photo of a recent print with the first layer up, showing even lines.
- On an X1 Carbon, a photo of the Device and Serial Number screen with its usage time.
- On a P1S, whether it printed carbon- or glass-fiber filament on the stock nozzle.
- Whether the carbon rods were ever greased. They shouldn't have been.
- The plate in the photos, with even texture and no bald patches.
- The AMS, buffer and cable if it's a Combo, and a short video of a color change.
- A factory reset before shipping, which Bambu says removes the seller's account.
- The original foam and heatbed screws for shipping.
Our guides to checking a used 3D printer and accounts, firmware and cloud binding go into each of these.
