"Steel Bug" 3d Printer

This is my home built 3D printer. Its design is inspired by a similar design by Patrick Hood-Daniel at buildyourcnc.com. Now that I've completed my CNC plasma cutting table, I've decided to build this printer entirely out of metal.

The base structure is 1/4" plate steel. Any moving parts have been machines from 6061 aluminium to reduce weight.  The Axis are driven by NEMA 23 stepper motors. The X and Y axis are belt driven, while the Z axis is lead-screw. The Y and Z axis rides on 4 V-groove bearings but for the X axis I chose to go with linear slide bearings for both strength and accuracy.
Here the X and Z axis are shown. Mechanical limit switches are installed to allow the machine to "home" its positions. Later, an optical Z axis limit was added ( not shown here) to home the Z axis to the correct distance to the build platform. This is similar to the homing design of the origonal Rep-Rap Design.
This is the underneith view of the machine. Here you can see the Y axis drive and build platform. The build platform is 12" X 12" square aluminium plate and uses a heater pad from qu-bd.com. I find this works quite well and keeps even the largest of prints from warping.
Here is a side view of the machine. All of the steel parts have been painted or clear coated to prevent rust. The ways and bearings have been oiled and this machine is ready to go. For this printer I tried using the MBE Single extruder V9 from qu-bd.com. However I have been less than impresed with it's design. I am currently building my own extruder to solve the V9's design flaws.