Jasper Tools Model-240 Pro Circle Guide
The Model M240 PRO Jasper Circle Guide is the same as the M240 Guide except it is made of virtually unbreakable polycarbonate plastic.
The circle Diameter distances are given in Inches. The maximum Circle Diameter is 18” + 3/16” and the minimum circle diameter is 1”. The Circle Diameter can be chosen by adding up the inches on the bottom with the inches on the left side. Together they make the final outer circle diameter, when a ¼ Inch bit is used. It makes 276 different size circles from 1inch to 18 3/16 inch in 1/16 inch increments.
The Graph’s below will give the Circle Diameter distances in Cm’s. Distances from the top graph can be added to the bottem graph to get the desired diameter value.