Bambu Lab P1S Combo Review: Why We Skipped the P2S

We bought the Bambu Lab P1S Combo, and we love it. It's the P1S 3D printer bundled with the AMS (Automatic Material System), the box on top that holds four spools and switches colors for you.

The newer P2S was already out when we were shopping, so we had a real choice between the two. We compared them side by side, went with the P1S, and spent the money we saved on filament. Below we'll explain why, plus the setup step that confused us, the add-ons that made a real difference, and what we've learned after printing a whole lot of dragons and toys.

See the Bambu Lab P1S Combo on Amazon

P1S Combo vs P2S Combo: What's Different?

Both printers are enclosed, both print fast, and both have the same 256 x 256 x 256 mm build volume. Here's how the combo versions compare, based on Bambu Lab's specs and Amazon prices when we checked:

Why We Chose the P1S Combo (and Bought Filament with the Savings)

Bambu still sells the P1S alongside the P2S, so when we were deciding, we had both in front of us. The P2S is a nice upgrade. The touchscreen is easier to use, the quick-swap nozzle saves time, and the hardened steel parts let you print carbon fiber and glass fiber filaments, which aren't recommended on the P1S.

But when we looked at what we actually planned to print, most of those upgrades didn't change much. Our prints are mostly PLA and some PETG: dragons, toys, organizers and gifts. For that, the P1S prints just as well. The build volume is the same, and the speed difference is hard to notice on a typical print.

The feature we were most tempted by was the AMS 2 Pro's filament drying. We figured a few dollars of rechargeable silica could handle humidity instead, and as you'll see below, it did.

The P2S Combo cost about $220 more when we checked. That's roughly ten spools of PLA. We'd rather have the filament! We've been printing happily ever since, and we haven't regretted the choice.

If you plan to print engineering materials like carbon fiber nylon, or you just love a touchscreen, the P2S is worth a look. For everyone else, the P1S Combo is the better value.

Why the AMS Is Worth Getting

You can buy the P1S without the AMS, and you can add one later. We're glad we got the combo. Here's what the AMS does for you:

• Multi-color prints. It holds four spools and switches between them automatically, so you can print a dragon with a red body and gold wings in one go. You can link up to four AMS units for up to 16 colors.
• Less spool swapping. Even for single-color prints, it's nice to keep your four favorite colors loaded and ready to go.
• Backup when a spool runs out. If one spool runs out mid-print, it can switch to another spool of the same filament and keep going.
• A closed box for your filament. The lid keeps out dust, and with good desiccant it keeps the filament dry (more on that below).

One limit to know: the AMS doesn't handle flexible TPU. For TPU, you feed it from the spool holder on the back of the printer.

Unboxing and Setup, Step by Step

Bambu says setup takes about 15 minutes, and that's about right. Bambu's official P1S Combo unboxing guide has photos for each step. Here's the short version:

1. Open the box and lift it out. Remove the foam and air bags on top, then use the two plastic handles to lift everything out onto a flat surface. Remove the plastic bag and peel the protective film off the panels.
2. Find the Quick Start Guide in the upper side cover. It's worth a read.
3. Take out the AMS and accessories. Remove the foam around the AMS, undo its 2 shipping screws and lift it out. Grab the PTFE tubes and the desiccant bags from inside it, too.
4. Remove the rest of the packing. Undo the 4 screws holding the AMS bottom bracket, take out the foam inside, cut the two zip ties holding the toolhead, and peel off the protective tape.
5. Undo the 3 shipping screws on the Z-axis. These hold the bed in place during shipping. Don't touch the foam under the bed yet. (See the next section.)
6. Install the screen and spool holder. Plug the cable into the screen (watch the orientation), pop it into its slot, and screw in the spool holder.
7. Set up the AMS. Put the AMS on top of the printer, connect the PTFE tubes, then connect the cables: the 4-pin cable from the filament buffer to the printer, and the 6-pin cable from the buffer to the AMS.
8. Plug it in and run the self-test. Turn it on and follow the on-screen steps. This is also when you connect it to Wi-Fi and the Bambu Handy app.
9. Remove the foam under the bed after the self-test finishes.
10. Load your filament and start printing!

Don't Pull Out the Foam Under the Bed (Yet)

This is the step that tripped us up, and we couldn't find a clear explanation of it anywhere online, so here's what we learned.

When you open the door, you'll see a block of packing foam wedged under the print bed. After pulling out all the other foam, it's really tempting to yank that one out too. Don't. It's pinched tight between the bed and the bottom of the printer, and pulling hard on it risks bending something or knocking the bed out of alignment.

Here's what to do instead:

1. Remove everything else first. Take out the other foam, cut the zip ties on the toolhead, and peel off the tape.
2. Unscrew the 3 Z-axis shipping screws. These lock the bed in place for shipping. Once they're out, the printer's motors can move the bed.
3. Leave the foam where it is, plug in the printer and start the self-test.
4. Let the printer do its thing. During the self-test, the printer homes and levels itself, and it raises the bed up off the foam. Be patient. The self-test takes a while.
5. Once the self-test is finished, pull the foam out. With the bed raised, it slides right out with no tugging.

Bambu's guide does say to remove it after the self-test, but it doesn't explain that the bed lifts itself off the foam. Once you know that, it all makes sense.

One more tip: if the bed doesn't move at all, double-check that all 3 shipping screws are out before you try again.

Add a Purge Bin Before Your First Print

When the printer changes filament, it pushes out a little waste plastic through a chute on the back of the printer. Bambu suggests setting the small box your filament came in under the chute to catch it. Later, you can print a nicer bin. Search for "P1S purge bin" on MakerWorld and you'll find plenty.

Single-Color vs Multicolor Printing: Speed and Waste

Single-color prints are fast. The P1S really moves, and a print that would take most of a day on an older printer can be done in a few hours.

Multicolor prints are a different story. The same model printed in four colors can take way longer than it does in one. Every time the color changes, the printer has to cut the filament, pull it back into the AMS, feed the new color in, and push out the old color before it can start again. On a model that changes color on every layer, that adds up fast.

It also creates waste. You'll get a little pile of purged plastic (people call it "poop") out the back, and some prints need a purge tower on the plate too.

A few ways to cut down on the time and waste:

• Use fewer colors when you can. Two well-chosen colors often look just as good as four.
• Print several copies at once. The purge happens per layer, not per object, so filling a plate with several copies spreads the waste out.
• Flush into infill or objects. Bambu Studio can push some of the purge into the model's infill or into a spare object instead of the waste chute.
• Print single-color pieces and assemble them. Many models on MakerWorld come split by color, so you print each part in its own color and snap or glue them together.

The Tool Kit We Recommend

The P1S comes with a few basic tools, but we picked up this 68-piece 3D printer tool kit, and we really, really like it.

• The flush cutters are great. They snip support material and trim filament ends cleanly. We use them on almost every print.
• The scraper is a must. Some prints stick hard to the plate, especially small ones and anything in PETG. The angled stainless steel scraper gets under them without gouging the plate.
• The deburring tool and files clean up rough edges and support marks.
• Nozzle cleaning needles and brushes come in handy when something clogs.
• Everything has a spot in the zippered case, so the tools don't end up scattered around the printer.

Tip for stubborn prints: the build plate is flexible and magnetic, so you can lift it off and flex it to pop most prints loose. If something still won't let go, put the plate in the freezer for a few minutes. The plastic and the plate shrink at different rates as they cool, and the print usually pops right off.

See the 3D Printer Tool Kit on Amazon

Upgrade the Air Filter to HEPA

The P1S comes with an activated carbon filter, which helps with odors and some fumes. But there's no HEPA filter, so it doesn't do much for the tiny plastic particles printers give off.

We upgraded to these replacement filters. Each one has a HEPA 13 layer for fine particles and an activated carbon layer for odors and VOCs. They drop right into the same slot as the original filter on the P1S (they also fit the X1 and P1P). The 2-pack gives you a spare, and the listing says each one lasts about 2 to 4 months.

See the HEPA Filter 2-Pack on Amazon

Fumes and Particles: PLA vs PETG vs ABS

Here's something we didn't think about at first: the P1S is enclosed, but it isn't airtight. Air gets in and out around the door, the lid and the back. A filter helps, but it can't catch everything.

All plastic filament gives off some ultrafine particles and VOCs (volatile organic compounds) when it's melted. How much depends a lot on the material:

• PLA: The lowest emissions of the common filaments, with a faint, slightly sweet smell. This is what we print most.
• PETG: Also fairly low, with little smell, but more than PLA.
• TPU: Somewhere in the middle.
• ABS and ASA: Much higher. They give off far more particles, plus styrene, and you can definitely smell them.
• Nylon and polycarbonate: Higher too, and they print hot.

So ventilation matters, especially for anything beyond PLA. Here's what we do:

• Open a window when we can, and keep the printer out of bedrooms.
• Run a room HEPA air purifier near the back of the printer. That's where most of the air comes out, so on days we can't open a window, the purifier catches particles right where they leave the printer.
• Vent ABS and ASA outside if you print them a lot. Lots of people print an exhaust adapter that connects the printer's back fan to a dryer hose running out a window.

Keeping Filament Dry: How We Went from D to A

Filament soaks up moisture from the air, some types more than others. PLA is fairly forgiving, while PETG, TPU and nylon are much more sensitive.

What happens when filament gets damp

When wet filament hits the hot nozzle, the water inside it turns to steam. You'll notice:

• Popping or crackling sounds while it prints
• Lots of stringing and wispy hairs between parts
• Rough, bubbly or fuzzy surfaces
• Weak prints where the layers don't bond well
• Filament that turns brittle and snaps, sometimes inside the AMS
• Under-extrusion and, eventually, clogs

The good news is that damp filament can usually be dried out in a filament dryer and printed normally again.

The AMS humidity indicator

The AMS has a humidity sensor that shows up in the app as a letter from A to E. A is the driest and best. The AMS doesn't heat or dry filament on its own. It relies on desiccant to pull the moisture out.

It comes with a few desiccant packets. Before you load filament, take them out of the plastic bags they ship in, or they can't absorb anything. (Bambu's guide reminds you of this, and it's easy to miss.)

Even with the included packets out of their bags, our AMS was stuck at a "D" reading. The included packets also aren't rechargeable, so once they're full, they're done.

What fixed it: rechargeable silica gel

We bought these rechargeable silica gel packets and tucked them into the spare spaces in the AMS. They have orange beads that turn dark green when they're full of moisture, so you can see at a glance when they need recharging. To recharge them, the listing says to microwave them for 2 to 5 minutes or bake them at 200 to 250°F for 30 minutes to 2 hours.

See the Rechargeable Silica Gel Packets on Amazon

We also bought the same orange indicating silica gel in loose beads, in a 1-quart jug. We printed small containers that fit in the front of the AMS, between the filament feeders, and filled them with beads. (We used the free SPILLPROOF AMS Desiccant Box from MakerWorld.) The beads recharge in the oven at 200 to 250°F or in the microwave on defrost.

See the Silica Gel Beads on Amazon

With the printed bead containers up front and the packets in the spare spaces, our AMS went from a "D" to an "A", the best reading. It's stayed there as long as we recharge the silica when it turns green.

For the full details, including desiccant vs silica gel and how to recharge it, see our guide: Why Your Bambu AMS Needs Silica Gel.

Storing filament that isn't in the AMS

The AMS only holds four spools. The rest of ours go into vacuum-seal bags with a silica packet inside each one. They take up less room, and the filament stays dry until we need it.

Which Filament to Use for Which Job

We've printed dragons, toys and lots more. Here's a quick guide to the most common filaments and what each one is good for:

If you're just starting, stick with PLA. It's forgiving, inexpensive and comes in every color you can think of.

Bambu Handy App vs Bambu Studio

There are two ways to run the printer, and you'll want both:

• Bambu Handy (phone app): It's wonderful. You can watch the print on the camera, get notified when it's done or something goes wrong, check the AMS humidity, and start prints from MakerWorld right from your phone.
• Bambu Studio (PC and Mac): This is where you get a whole lot more control. You can paint colors onto a model, add or adjust supports, change layer heights and infill, arrange several models on one plate, set flush volumes to cut down on waste, and fine-tune the settings for each filament.

We use Handy for everyday printing and checking in, and we switch to Bambu Studio whenever we want to customize a print.

MakerWorld: Ready-to-Print Models

MakerWorld is Bambu Lab's free model library, and it's one of the best things about owning a Bambu printer. There are over a million models, from articulated dragons and fidget toys to kitchen organizers and replacement parts.

It's built right into the Bambu Handy app and Bambu Studio. Find a model you like, pick a print profile that someone has already tuned for your printer, and send it to the P1S. It couldn't be easier.

The Bottom Line

We LOVE this printer. The P1S Combo is fast, reliable and easy to set up, and the AMS makes multicolor printing fun. The P2S is a nice upgrade, but for the kind of printing most families do, it isn't worth the extra money. Buy the P1S Combo, add a good tool kit, a HEPA filter and some rechargeable silica, and put the rest toward filament.

Check the Bambu Lab P1S Combo Price on Amazon