Step 1) All parts needed for this project are within XCS software, a little sizing from selected pieces and you are all set. First a circle is created and and a pie shape is selected from the shapes list, this pie shape is sized to the same as the circle. a second pie shape is created from copy and pasting the shape onto the work area. This second pie is need for the second part of the center finder, with a rectangle sized the same as one edge of the pie shape it is united with the pie shape. all the other pieces are finished with the use of the combined feature.

Step 2) In the step the pie and the circle takes on a new shape after the combine feature and subtract is selected, so it now looks like there is a piece of pie missing. a small circle is also added in the center of that new shape for a marking lead or pencil end so it stays in the correct place when marking the center.

Step 3) So this is where the new created pieces are ready to be engraved and cut. Once cut the top engraved item is glued on top of the pie shape. in order to have this accurate it is glued with the circle having the missing pie shape 180 degrees straight up and the longer engraved piece is glued matching the outside circular edge of the bottom. with this glued together it give a place to slide whatever you need marked to fit squarely in the corner and you simply make a mark turn it 90 degrees and mark again. and you are done.The hole on the one side is for optional hanging when not in use.