Easy way to do it is with the tape measure. From either edge, just use the tape measure to pull out a line at the spacing you want. When you start drawing, type in the dimension, like 5" and press enter. Repeat this for each spacing you need. You can do the same thing from a 90 degree edge to enable intersecting lines. If you want to then draw circles, select the circle tool and draw from the intersection to the diameter you need.
To create a 'mirror, use components. Draw one side and when completed with the layout, select all elements and right click and choose 'make component.' That could be one side of your base, for example.
Once a component is created, just use the move tool (four arrows) and select the component and press the + key. That will show up in the cursor and you can drag the component across a set dimension by typing a number and enter. Once on the other side, right click on it and choose 'flip' and you can choose to flip on the red, green or blue axis. That gives you a mirrored side in the right orientation. If you edit one component, it is reflected in all the components you duplicated.
Further, if you create one component and duplicate it, you can select the duplicate and right click and say 'make unique' and that will decouple one from the others so you can tweak it with no waterfall to the other components
Hope this helps and answers your questions -
neil
