To help steady the pencil, this hack helps by creating a small notch at the end of the ruler in the combo square. Then, the ...

A PCB ruler is a common promotional item, or design exercise. Usually they have some sample outlines and holes as an aid to PCB design, but sometimes they also incorporate some circuitry.

A ruler seems like a pretty simple device; just a nice straight piece of material with some marks on it. There are some improvements out there to the basic design, like making it out of something ...