I wanted to see what the largest diameter circle I could get from an irregular shaped small piece of wood. There are templates available for finding the center of log sections and locating the center point, but I was working with small stock. I made this center finder/drawing aid at the TechShop, www.techshop.ws.
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I started by placing a .07 inch diameter circle in the center of a 1 inch diameter circle and then constructed concentric circles spaced at 1/8” increments. I used Corel Draw as that is the “resident” program for the Epilog lasers. I made the .07 inch circle "hairline width" and the larger circles .014 inches line width for etching.
In order to make it easier to see which circle you were looking at when using the circle center finder, I made every-other circle a dashed line.
To make the circle drawing aid I radiated lines at 30 degrees and located a small circle at the intersection of the lay-out line and each successive circle. These small circles must be “hairline width” to cut, leaving pencil point holes. I then erased the lay-out lines.
I added a top knot with a hanging hole and specified the perimeter line and hanging hole circle as “hairline width”.
Using the Epilog laser I engraved and cut the center finders from .093 inch thick acrylic plastic. To use, place the center finder over the stock in question and “eyeball” the largest circle that will fit. Use a push pin to hold the center and scribe a circle with a pencil.