Here are my go to settings for Blender when I am modelling for a 3D Print
To design in inches and export an STL file at the proper scale:
- In the Properties Panel, go to the Scene Tab.
- In the Units section, Change the Units to “inches”, the length to “imperial” and the Unit Scale to 0.0254.
- When you export your model as an STL file, set the scale to 25.4.