I am the designer of the RepRap Wallace, and most of my current work is on this design and related projects. I'm also working on a design for a compact and easy to use extruder to replace the Wade's/Greg's extruders, which seem large and unwieldy next to the other Wallace parts.
My first Reprap was an oversized Huxley that I built by cutting the rods and belts longer to make it almost as big as Mendel. The build platform was 8"x8" (about 195x195mm usable), but the outside was only 15"x14"x13". This machine has since been disassembled, and many of the parts were re-used to build the first Wallace.
I had a lot of trouble getting reliable extrusion, so I took the bowden cable out of the equation and bolted the extruder directly to the carriage. This seems to work fine with the NEMA 14 motors I bought, which meet the 13.7 N-cm torque requirement for Mendel.
I made a few updates to the design:
- Redesigned the y-bar clamps (not pictured) for Huxley and Mendel to print in one piece and require no screws. Instead, the nuts on the threaded rod are tightened-down on piece to clamp the smooth rod. This design was later incorporated into the Prusa Mendel
- pulley extenders to fix the x-belt alignment so that it no longer rubs against the carriage. There are also replacements for x-blunt-plate_1off.stl and x-motor-end-clamp_1off.stl that have these extenders integrated. Note that these are not symmetric, and the L-shaped portion is designed to align with the belt clamps on the carriage.