Mirroring a STL file in Bambu Studio takes three steps: import the model, select the mirror tool, and choose which axis to flip
Open Bambu Studio and load your STL file by going to File > Open Project or by dragging the file directly into the workspace. Once the model appears on the build plate, click on it to select it — you'll see it highlighted with a blue outline and control handles appear around it.
With the model selected, look at the left panel where you see rotation, scale, and positioning controls. Find the Mirror button — it looks like two triangles facing each other. Click it, and a dropdown menu shows three options: Mirror X, Mirror Y, and Mirror Z. Each one flips the model along a different axis. Choose the direction that matches what you need, and the model will instantly reverse on that axis.
After mirroring, you can rotate or reposition the model if needed before printing. The mirrored version is now ready to slice and send to your printer.
Key Takeaways
- Import your STL file into Bambu Studio by opening it through the File menu or dragging it into the workspace.
- Select the model on the build plate so it shows the blue outline and control handles.
- Click the Mirror button in the left control panel and choose X, Y, or Z axis depending on which direction you need to flip.
- The mirror happens instantly; you can then rotate or move the model before slicing and printing.
Understanding the three mirror axes
The X, Y, and Z axes correspond to different directions in 3D space. The X axis runs left to right across your build plate, the Y axis runs front to back, and the Z axis runs up and down. When you mirror on the X axis, the model flips left-to-right. Mirror Y flips it front-to-back. Mirror Z flips it upside down.
If you're not sure which axis you need, think about which direction the model should reverse. Hold the model in your mind and imagine which way it needs to flip. That's the axis to use. You can always undo the mirror by pressing Ctrl+Z (or Cmd+Z on Mac) if you pick the wrong one and try again.
Mirroring before or after rotating
You can mirror a model at any point in your workflow — before or after rotating it. However, if you rotate the model first and then mirror it, the mirror will happen along the rotated axes, not the original ones. This can produce unexpected results if you're not paying attention.
The safest approach is to mirror first while the model is in its default orientation, then rotate if you need to. This way you know exactly which direction the mirror will go. If you've already rotated and want to mirror, undo the rotation first, mirror, then rotate again to your desired angle.
Checking your mirrored model before printing
After mirroring, take a moment to visually confirm the model looks correct. Rotate it around in the viewport by clicking and dragging with your middle mouse button (or two-finger drag on a trackpad) to see it from different angles. Look for any text, logos, or asymmetrical features that should now face the opposite direction.
If the model has text or a logo that should read correctly, make sure it's now reversed — that's the whole point of mirroring. If something looks wrong, undo the mirror and try a different axis. Once you're satisfied, proceed to slice the model and send it to your printer.
Mirroring multiple models at once
If you have several models on the build plate and need to mirror only one, make sure only that model is selected before clicking the Mirror button. Click on the model itself to select it individually. The blue outline will appear only around the one you want to mirror.
If you want to mirror all models on the plate at the same time, select them together by holding Ctrl (or Cmd on Mac) and clicking each one, or by drawing a selection box around all of them. Then click Mirror and choose your axis — all selected models will flip together.
Undoing or re-mirroring a model
If you mirror a model and change your mind, press Ctrl+Z (or Cmd+Z on Mac) to undo the mirror instantly. The model returns to its original orientation. You can undo multiple steps this way if you need to go back further in your workflow.
If you want to mirror a model that's already been mirrored, simply select it and click Mirror again with the same axis — it will flip back to the original orientation. Mirroring twice on the same axis always returns the model to where it started.
Frequently Asked Questions
Can I mirror just part of a model?
No, the mirror tool in Bambu Studio mirrors the entire selected model. If you need to mirror only a portion, you'll need to edit the STL file in a 3D modeling program like Fusion 360 or Blender before importing it into Bambu Studio.
Does mirroring change the size of the model?
No, mirroring only reverses the model's orientation. The dimensions and scale stay exactly the same. If you need to resize the model, use the Scale tool in the left panel instead.
What if I mirror a model and it looks wrong?
Undo the mirror with Ctrl+Z and try a different axis. The wrong axis will produce a result that doesn't match what you expected. Once you find the correct axis, the model will look right. If it still seems off, check the original STL file in a 3D viewer to confirm what the model should look like.
Can I save a mirrored version without affecting the original file?
Yes. Once you mirror the model in Bambu Studio, save the project as a new file through File > Save Project As. This creates a separate project file with the mirrored model. Your original STL file remains unchanged.