How to Open STL and 3MF Files in Bambu Studio: Your First Print, Step by Step
You found a design you love and hit download. Then the folder opens and you see a pile of files. A few pictures, an STL, maybe a 3MF, maybe a PDF. Which one do you actually open?
A lot of people get stuck right here, and nobody tells you which file matters. Once you know, it's a handful of clicks from the folder to the printer.
Honestly, my own first Bambu print was surprisingly easy. Bambu Studio is built to work with the printer, so setting it up and starting that first print felt simple. This guide walks you through the same steps, and should help you get your first 3D prints in a breeze.
New to Cubee? We're a commercial design library for people who sell their prints, so the examples below come from our catalog. There's a short note for newcomers, and one for members, at the end.
What's Actually in the Download
Most design downloads hold three kinds of files. Only some of them are printable.
STL is just the shape. No colors, no settings, nothing else. Every slicer opens it, which is why almost every design ships with one.
3MF is the shape plus extras. It can carry the designer's plates, colors and print settings. Bambu Studio saves projects as 3MF, so a designer who prints on a Bambu often includes one.
So which one should you open? If there's a 3MF made for Bambu Studio, start with that. It's the designer's own setup. If there's only an STL, that's fine too. You'll just pick a few settings yourself.
On the Hive, every design page has a Files tab with every file listed, and a How to Print tab with the designer's notes. Here's the Axolotl Articulated Figure Keychain, which we'll use as the example in this guide.
Setting Up Bambu Studio Once
Download Bambu Studio for Windows 10 and up, or macOS 10.15 and up. It's free.
Pick the regular release. The "Public Beta" builds on the releases page are for people who like testing new things.
Open it and choose your printer and nozzle size. Most printers ship with a 0.4 mm nozzle, so pick that unless you've changed it.
Don't own a Bambu? You can still use it. Bambu Studio describes itself as software for Bambu Lab and other 3D printers, with presets for brands like Prusa, Creality, Elegoo, Anycubic and Voron.
Prefer another slicer? OrcaSlicer, PrusaSlicer and Cura all follow the same basic flow: open the file, check a few settings, slice, print. The buttons have different names, but everything below still applies.
How to Open STL and 3MF Files in Bambu Studio
Bambu Studio opens .3mf, .stl, .step, .obj and .amf files. Here's how to open an STL:
Drag the STL from your folder onto the Bambu Studio window. Or go to File, then Import.
The model lands on the plate straight away.
Check the printer and nozzle, top left. Bambu Studio remembers the ones you used last.
In the screenshot below, mine was still set to a 0.2 mm nozzle from an earlier print. If yours shows the wrong one, change it before you slice.
A 3MF takes one extra step. Here's how to open one:
Drag the 3MF onto the window, the same way.
If something is already on the plate, a box called "Drop project file" pops up.
Choose Open as project for a first print. It loads the shape, the plates, the colors and the designer's settings.
Click OK.
The other choice, Import geometry only, takes just the shape and keeps your own settings. The Bambu wiki explains both.
Now look at the printer name again. A project brings the designer's printer with it. Below, opening a Bambu 3MF switched my printer to the designer's P1P.
If that's not your printer, pick yours from the dropdown. Bambu Studio may ask what to do with the designer's changed settings. Keeping the designer's values is usually the safer bet.
Common 3MF Warnings and What They Mean
Sometimes a 3MF opens with a note at the top of the screen. They look alarming the first time. Most of them aren't.
"The 3mf is not from Bambu Lab, load geometry data only." The file came from another slicer. Bambu Studio loads the shape and skips the settings. Pick the settings yourself, like with an STL.
"The 3mf is generated by old Bambu Studio, load geometry data only." Same idea. The shape loads, the old settings don't.
"Newer 3mf version." The file was saved in a newer Bambu Studio than yours. Update Bambu Studio, then open it again.
None of these mean the download is broken. If a file really won't open at all, try Import geometry only. And if that fails too, ask the designer or the platform you got it from.
Which Plate Do I Print?
Bigger 3MF projects often come split into plates. A plate is one slicing and print unit, so each one is a separate print job. You click a plate to select it.
Designers use plates to sort parts by color or size. The project below has four: three figures, each on its own plate, plus a fourth plate for the small parts.
For a first print:
Click the smallest plate to select it.
Press "Slice plate". It slices only that plate.
Leave "Slice all", under the small arrow, for later. The Bambu wiki covers printing several plates in a row.
The Few Settings That Matter on a First Print
The left side of Bambu Studio has a lot of numbers. You can ignore almost all of them for now. Check these four first:
Printer and nozzle. They should match the machine on your desk.
Plate type. Click the plate picture next to the printer and choose the plate you actually have. On some printers, a mismatch stops the print. It's also a top reason a first layer won't stick.
Filament. Pick what you've loaded, like PLA. Don't know the brand? The "Generic" version of that material is fine.
Supports. Open the Support tab. If the designer's notes say no supports, leave "Enable support" off. Our supports guide explains normal and tree supports.
Everything else can wait. The default profile for your printer is a good starting point. When you're ready to go deeper, our slicer settings guide for PLA, PETG and ABS is something you should refer to next.
Slice, Then Check the Preview
Click "Slice plate". Bambu Studio switches to the Preview tab.
Read the total time and the grams of filament in the Slicing Result box, top right.
Drag the slider on the far right down and up to watch the print grow, layer by layer.
Want to see what the printer will actually draw? Open the Color Scheme dropdown in the Slicing Result box and pick "Line Type". Every color is now a kind of line, and the list shows the time and grams each one takes. The Bambu wiki explains the full panel.
In this one, orange is the outer wall, the surface you'll see. Yellow is the inner wall behind it. Dark red is the sparse infill, the light pattern that fills the inside, and purple is solid infill. Blue marks overhang walls, the bits printed out over thin air.
That's also how you spot trouble. Does anything hang in mid-air with nothing under it? Then it needs supports.
Bambu Studio often spots this for you. It shows a warning about "floating regions" or "large overhangs" and suggests you re-orient the model or enable supports. A model that hangs over the edge of the plate gets a warning too. Move it fully onto the plate and slice again.
Sending It to the Printer
Once the preview looks right, you're nearly there. The green button next to Slice plate reads "Print plate". Its small arrow has a few more options.
To print over Wi-Fi:
Click "Print plate". The "Send print job" window opens.
Pick your printer.
Check the filament. With an AMS, Bambu Studio matches each color to a slot for you. With an external spool, you confirm the filament type yourself.
Press Send.
With a printer connected, the same window shows options like Auto Bed Leveling, Flow Dynamics Calibration and Timelapse. Leave bed leveling on for your first prints. The Bambu wiki recommends it when the first layer gives you trouble.
No Wi-Fi? Use the memory card:
Choose "Export plate sliced file" from the Print plate menu.
Save the file to the printer's microSD card.
Put the card in the printer and start the print from its screen.
The quick start guide shows both routes.
If the First Layer Won't Stick
If your first print fails, it's most likely the first layer peeling up. It happens to everyone, and the fixes are quick.
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Try these in order:
Wash the plate. Fingerprints are oily, and oil stops plastic from sticking. Bambu suggests hot water and dish soap, then let it dry.
Check the plate type in Bambu Studio. It has to match the plate on the printer.
Add a brim, a thin ring around the base. It's set to Auto by default, under the Others tab.
Skip the glue for PLA. Glue stick is for tougher materials, like PC, nylon, ABS and ASA on a textured plate.
Good First Prints to Try
Your first print should be small, flat on the bottom and free of supports. If it's done in an hour or two, even better. You learn the whole loop fast, and a failed print doesn't cost you much.
Just want to try the steps first? Two free classics work well:
3DBenchy, the little tugboat on Thingiverse. It was designed for testing printers and to print quickly, and it's been public domain since February 2025.
The XYZ 20mm Calibration Cube by iDig3Dprinting. Print it, then measure it to see if your printer is printing to size.
Free files are great for practice. If you plan to sell a print, check that file's licence first.
A few from the Hive catalog that fit:
Axolotl Articulated Figure Keychain by Biocraftlab. It prints in place, so it comes off the plate already moving. The one in this guide took about two hours at fine settings.
X-mas Candy Bowl by additiveworks. One part, no supports, and right on time for the season.
3D Dragon Bookmark by FantaZ. Flat and fast. The designer recommends a brim.
Doms Desk Organizer Modular System by Collecticraft. Useful, simple, and no supports needed.
After the first one, you'll notice every print goes the same way. The second one is already quicker to set up.
If you're new here: Cubee is a design library for people who sell what they print. Every design comes with a commercial licence, so you can sell the prints, not just make them. Our first-print favorites above are all in the community catalog. When you're ready to turn prints into sales, our guide on making your first dollar picks up where this one ends.
If you're already a Hive member: pick one design from the Hive catalog this week and open its How to Print tab before you slice. If the designer included a Bambu 3MF, open it as a project and you'll have their settings to start from. Stuck on a step? Ask in the members' Discord.
Happy first printing!
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