I've been working on this project offline and now have it working.  Today is the first day I've uploaded source code and STL files needed to build the unit.  I've got assembly and software notes on my machine (or in my brain) that are not really ready for publication, so its going to take me a little time to get everything documented here.  We are talking a day or two, not a week or two. I'll get those notes published, and then will start working on phase 2 of the project, which is perfecting exposure times and chemical recipes.  You can, for example, buy a 32 oz bottle of developer for $20, and another 32 oz bottle of etchant online for another $20.  Or, you can buy a jug of lye crystals, disguised as drain opener, from the local home improvement store for about $12 and you can make swimming pool's worth of your own developer.  Same for the etchant.