This is hopefully my last rebuild for this machine! I needed a larger work envelope, and want to be able to load materials without working over the rails. Placing the leadscrews andlinear bearings under the rails allowed this. I also upgraded the X axis to dual steppers to handle the heavier weight and add ridgidity to the wider frame. My work envelope increased from 30 x 25 to 33 x 30, while marrowing the footprint 6 inches!
My gantry design allows me to replace the front and back table connecting plates to give me another 3 inches of Y area, though as-is allows me to use form cutters right to the edge of the work and lead in. I also designed the bridge so that it cna be raised or lowered to either increase ridgidity for harder sheet goods, or raised for larger 3D work. These gussets are temporary until the proper ones can be made. I will also need to make gussets in front of the gantry legs once I'm all set up.
I also now use aluminum plate for the stepper mounts instead of HDPE; this also helps dissipate some heat. Gone also is the large timing belt in favor of two shorter belts on the X axis. I also designed the carriage and saddle for as little overhang as possible.
All connecting plates are still phenolic material, which I like to cut and has great strength and vibration-damping properties. A lot easier to cut than aluminum, too
You can see my build thread here: http://www.cnczone.com/forums/diy-cnc_router_table_machines/122070-one_thing_led_another.html
Motors - Xylotex 425 in-oz on X, and Z axis. SanyoDenki StepSyn 380 in-oz on Y
Drive - Gecko G540 assembled by DeepGroove1, 48V PSU, aluminum chassis
Controller - Mach3, on P4 1.6GHz
CAM software - Vectric Cut2D and VCarve Pro, OneCNC XR3 Mill Advavntage, XR4 Mill Expert
