Blender STL Resize Tutorial For CNC Files

Step-by-step workflow for resizing, adjusting, and exporting 3D STL files before CNC router carving. Click any image to open the full-size version.

*Note: Resizing or changing proportions can be useful for getting the most out of a block of wood or other material when carving a BAS Relief model on a CNC wood carving machine.

Stage 1

Open Blender

  1. Open Blender.

*Note: This tutorial uses Blender 5.1.

*Note: Blender starts with default camera, cube, and light objects already on the stage.

*Note: You need to remove all of those default items before importing your STL.

Blender STL resize tutorial stage 1 - Open Blender
Stage 2

Select Default Objects

  1. Ensure the selection tool is active.
  2. Drag a selection box around all three default items.
Blender STL resize tutorial stage 2 - Select Default Objects
Stage 3

Confirm Selection

*Note: The three default objects turn orange to show they are selected.

Blender STL resize tutorial stage 3 - Confirm Selection
Stage 4

Delete Default Objects

  1. Right-click one of the selected objects to open the object menu.
  2. Select Delete.
Blender STL resize tutorial stage 4 - Delete Default Objects
Stage 5

Import STL

  1. With the stage now clear, go to File > Import > STL (.stl).

*Note: The stage is now ready for your STL import.

Blender STL resize tutorial stage 5 - Import STL
Stage 6

Choose STL File

  1. When the Blender file browser appears, navigate to your STL file.
  2. Select the file and click Import STL.
Blender STL resize tutorial stage 6 - Choose STL File
Stage 7

Imported Model

*Note: Your STL file is now imported onto the stage.

Blender STL resize tutorial stage 7 - Imported Model
Stage 8

Resize With Object Properties

  1. Make sure Object Properties is selected.

*Note: You can resize the model by changing the X, Y, or Z scale values.

Blender STL resize tutorial stage 8 - Resize With Object Properties
Stage 9

Enable Viewport Gizmos

  1. Alternatively, use the viewport Gizmos controls and enable rotate and scale.
Blender STL resize tutorial stage 9 - Enable Viewport Gizmos
Stage 10

Scale With Gizmos

  1. Use the scale gizmos to reduce or increase the width, height, or other dimensions more easily.

*Note: Notice how the scale ratio values for X, Y, or Z change when the scale gizmo is used.

Blender STL resize tutorial stage 10 - Scale With Gizmos
Stage 11

Use Preset Views

  1. Use the preset viewpoints to switch between different model views.
Blender STL resize tutorial stage 11 - Use Preset Views
Stage 12

Adjust Model Height

  1. Use the scale gizmo again to reduce the model height as needed.
Blender STL resize tutorial stage 12 - Adjust Model Height
Stage 13

Export STL

  1. When you are ready to save the resized model, go to File > Export > STL.
Blender STL resize tutorial stage 13 - Export STL
Stage 14

Save Resized Model

  1. Rename the new STL model.
  2. Blender defaults the name to Untitled.stl.
  3. Save the file to the location you want.
Blender STL resize tutorial stage 14 - Save Resized Model