The dibond and sturdy versions are well tested and popular. The acrylic version, called mendel, hasn't been built for a long time and is not recommened.
The Huxley version hasn't been tested in its final form although one prototype has been made of an earlier version and a few snags fixed since.
machine\_name can be dibond, mendel, sturdy or huxley. To make your own variant copy scad\conf\mendel\_config.scad or scad\conf\sturdy\_config.scad to yourname\_config.scad. Then run `make_machine.py yourname`.
To view the model of the whole machine, open scad\main.scad. It will take several minutes to render (about about 5 minutes on my computer) but after that you can pan and zoom it at reasonable speed and changes takes less time to render. (Note: main.scad will only render correctly if conf\machine.scad exists, which is created by the make_machine.py script.)