Here are the steps to make an object for 3D printing that is 5cm x 5cm x 5cm:
1. Open a 3D modeling software like SketchUp and create a new file
2. Design a simple object that fits within the 5cm x 5cm x 5cm dimensions using basic shapes like boxes, spheres, cylinders, etc.
3. Make sure the object is one unified piece by grouping all components
4. Export the file as an STL file for 3D printing
5. The STL file can now be 3D printed at the specified size limits.