The idea of the ScrewRap design is to make a precision 3D printer without the ridiculous price tag that comes with it. The design is also made to require minimal tools. Currently the only tools I have required are a 3D printer (or a friend with one), and an allen key. Of course you will still need appropriate tools for all the electronics etc.

The overall design is based on Smartroad's Dual-Struder Fabricator, which can be found on thingiverse here: http://www.thingiverse.com/thing:90021. The major difference, however, is the ScrewRap uses leadscrews on all 3 axes. More details can be found on the RepRap wiki here: http://reprap.org/wiki/ScrewRap.