Blender 3D Printing by Example

Positioning with a reference cube or ruler

If you are not a fan of subtraction, instead of typing in exact coordinates, you can left-click on the X (red) axis arrow and move the hole to a spot you see fit. To help with placement, you could also add a temporary cube to your project, size it to your desired wall thickness, and use that as a math-free guide. Consider that little reference cube as "no man's land" and make sure no part of your cylinder ventures into that area:

Using a 2 x 2 x 2 cube as a reference when moving our cylinder hole.

In addition, Blender has a Ruler/Protractor tool you can use to check your work. This tool works in both ...