From Microsoft's website "Both editions (standard and professional) deliver powerful tools tailored to meet a variety of visual communication needs for business and technical professionals." It has been quite a while since I put system architectural diagrams and models together with the tool. I use it to create scale drawings. Are there better tools for that? I'm sure. Maybe CoralDraw. I know that CD is used to transmit structures for laser cutters. Maybe a search in the scratch building forum might help. I just use what I'm comfortable with.

Btw, you can download a trial version of Visio from Microsoft Office support. And there is a "Vision for Dummies" book out there. Maybe I should grab a copy for a refresher ...

The attached pics are the gruesome structural details of the Killer Chaos.

Visio has something that ITcalls layers (different from Photoshop layers). When you put a structure together you can apply 1 or more "layer" attributes to each piece (or group that is made up of 2 or more pieces). Then you can display or hide any combination of layers. You can then save all displayed information as a jpg. That's what I've done with the pictures that I upload.

You could do a kind of human body structure that includes layers "skeleton", "organs" and skin. With skin displayed that's all you see. You can adjust the transparency of skin to be 50% so that you can see it but you can also see underlying structures. You can turn off display of skin and you would see the skeleton and organs. Likewise, you could turn off display of organs (or change its transparency)so that the skeleton is displayed.

You can save structures as CADstructures so that people with Rhino 3Dcould import your work and develop a laser cutting image. And on it goes ...

I added a couple more that includes textures &shades that can be used to differentiate between the structures.