This page will cover the reasoning for why making parts in a Sketchup model symmetrical is a good idea. A symmetrical part essentially means that, if you were to draw a line directly through the center of it, both halves would be exactly the same.
Here is a quick example to explain the reasoning behind this. In the picture below, there are two identical parts, one of which is flipped over onto its back.
This part is not symmetrical. If you were to put one on top of the other, the holes would not line up. This is something that you need to watch out for when you are designing things in Sketchup.
Here is the symmetrical version of the same part. As you can see, the holes will line up just fine in this version.
Although the examples I just used are blatantly obvious as to whether or not they will work correctly, while drawing a design, it is not always so obvious. More often then not, the problem will go unnoticed, and it’s not until you’ve already gone to the trouble of cutting out the design with your CNC and start putting things together that you notice something is wrong.
Believe me, I’ve done it myself once or twice. : )
