Building a centring jig is a very interesting project as a shop jig. The purpose of this centring jip is to do exactly what it says. It will quickly and easily find the centre line of a board right on dead centre.
I’m sure from time to time you have had the chore of trying to find the dead centre of a board whether it is the centre of the edge or on the face and found that it was time-consuming and not always easy.
Building a centring jig is constructed primarily from scraps that you will have around the shop. It will require 3/4″ material about 1 1/2″ wide by 6″ long. A couple dowels 1/4″ or 5/16″ you may have kicking around the shop and a regular lead pencil.
If you want to find the centre on a boards edge, simply turn the board edge up placing your jig on the board with the dowels down and each tightly against the board. Then just simply pull the jig down the length of the board marking dead centre as you go.
If you require marking wide boards, simple make a jig the same way but longer ( maybe 16″ instead of 6″ )