This page will cover the reasoning for why making parts in a Sketchup model perfectly identical when designing them to be cut out with a CNC is a good idea.
What this means is that, when two or more parts in Sketchup are similar to one another but still slightly different, they should be changed so that they are exactly the same and therefore completely interchangeable, even when interchangeability doesn’t appear to be necessary.
Here is an example to help explain. In the two pictures below, you can see two different perspectives of a design that I made in Sketchup. In both pictures, there is a red circle around a set of two holes. The holes in the right picture are completely unnecessary because there will be no stepper motor mounted on that side.
Even though it might take extra work to copy, paste, move, and rotate the part with the holes for the stepper motor mount over to the other side, which doesn’t even need those holes, it should still be done.
There are several reasons for why, but, generally, it is just good planning to design your models like this because there is no telling what the future of each of those individual parts will be. For example, it could be that one day that stepper motor will need to be mounted the on the other side.
There is also the possibility that you will mistakenly put two similar parts in the wrong places simply because, at a glance, you didn’t notice they were different. If the parts are identical however, it doesn’t matter where you put them.
