start with XCS software and with the insert button select rectangle, make this 1" tall and 6" long.

Once you have done this select piece and right click to give copy option, copy this item

Now that you have copied the item anywhere on the work area right click again but this time select paste, you will want to do this step 2 times so you have a total of 3 rectangles.

Take one of them and overlap on the one corner of the other, take time to make sure it is exactly in the corner. If zooming in helps to make sure go ahead and do this so you get it as close as possible.

Now that you are satisfied it is in the corner, use the combine feature to unite the 2 pieces together. You will see in the second picture you end up with a L shaped item.

take that new L shaped object and repeat the copy and paste procedure so you end up with 2 of these on your work area.

Now take the 3rd rectangle you created earlier and rotate it to a 45° angle. You will want to place the end in the very corner of the L shape, once again zoom in to see you have it exactly matching the edges. You then can use the combine feature to unite this item to create a L shape with a ramp going 45° away that looks like in the picture.

From all that creating you now have 2 pieces you need that go on top of each other, they look like what is in the picture. If you do not have this at this point look back a step or 2 to make sure.

This next step is totally optional to add a an engraving of a name, a logo, a shop calling card whatever you like. If you do not want to add a name you can skip this step. first in order to apply a name of sorts you need to flip one of them 180° so the engraving appears on the proper side. you can create any kind of lettering from the XCS software and set the desired engraving depth/color/power.

I have labeled the bottom with words, the input form the work can be turned off so it does not get engraved, it is only there so you know that piece gets glued on the bottom.

I have laid the 2 pieces in such away they use up the least amount of materials as possible. when framing you will see the following like in the picture, all the outside edges are set to cut with the power set to 100% speed at 7mm/s and 3 pass, the engraving can be set to the desired need. these setting may be different depending on what laser machine you have, a 5W will need to be set lower and possibly more passes and a 20W may need less power or a faster speed with less passes.

As you can see I cut these pieces out from just some scrap pieces of 1/4" (6.3mm) birch plywood. once the machine is finished they are ready to be glued together with wood glue. take time and care to line the bottom with the top on both the long edges before gluing sets and dries.

Now that the new guide is glued together you simply place it on the edge of any circle, with a pencil you can make a mark folloing the 45° edge that runs into the center of the circle, slightly move the guide around the outter edge and make again to achieve a X.... when you have done this you will have the center of the circle without guessing every time...enjoy. when the circle and guide is flipped over you can see how the edge of any circle will fit into the corner against the second layer as a stop.