This construction set is intended to be a customisable frame for a working 3D printer, but it can be used for anything you deem it to be fit for. When you tighten it up with some M3 nuts and screws, it becomes quite a rigid structure.
One of the novelties of 3D printing and the RepRap project in particular is the fact that you can print another 3D printer from one that already exists. But this is tempered somewhat when one sees that most of the "replicated" printer is actually made of metal rods. It's much more fun when you see that it's mostly made of printed plastic!
This construction set is just for a frame. Attachments for X,Y,Z axes and electronic mounts still need to be developed.
Print as many of the different parts as you need! Screw them down with M3 nuts and bolts to increase rigidity.
The right-angle-joint and the t-joint parts have built in support structures in the STL itself. The-right-angle-joint in particular has thermal barriers to stop it from curling off the platform.
Print with no automatically generated support strcutures.