rapid prototyping machine

Updates:

update 1: progress on the prototype electronics (4/1/12)

The rapid prototyping machine's core goals:

Quality
The current generation of low cost rapid prototyping machines on the market are constructed out of acrylic(brittle) or wood(shrinks/expands with humidity). The structural integrity of these machines is more on the order of something assembled with a child's construction set than a machine that will hold tight tolerances reliably.
Accuracy
The machine is designed in a way that makes manufacturing errors very apparent during the assembly process, it becomes nearly impossible to fit together if holes do not match exactly between matching parts because the steel rods bind inside the aluminum posts on each corner of the machine(holes are reamed on mill, rods are ground to +- .0005").
Affordability
The electronic control systems used in these small machines are fairly trivial, we plan to eventually consolidate of the components onto a single printed circuit board to avoid using any sort of pre-made breakout boards. The metal components don't have too many complex features at the moment, and will stay that way to keep costs down.
Ease of user modifications/hacks
The machine's corner posts are made of solid aluminum bar. Attaching extensions can be accomplished by drilling and tapping holes as needed (alternatively corner posts can be offered with tapped holes in useful locations). An API will be made available that gives direct access to positioning system as well as GPIO pins from Python, Java, C#, C++, and JavaScript (yes, you can control everything through your browser). This is made possible by running this daemon (which will no longer be dependent on the .NET framework in the next iteration).

You can check out the progress on the rapid prototyping machine on the following pages:
software
model
prototype