Homebrew PCBs

Although not exactly what you are asking for, I did build my own CNC system and I do use it successfully for isolation routing of PCBs.
True it is not as fine-lined as a photo process, it is a lot louder and makes some dust, but there are no nasty chemicals & such.  Like life, it's all about trade-offs.
Anyhow, you might pick up a trick or two from my blog.  Cheers and good milling.

http://woodworkerbcncrouterproject.blogspot.com/