Significant redesign based solution:
X axis: http://www.thingiverse.com/thing:866604
Y Axis: http://www.thingiverse.com/thing:949082
Z axis: http://www.thingiverse.com/thing:1038673
Anti Wobble: http://www.thingiverse.com/thing:1089626
Aluminum heatbed corners: http://www.thingiverse.com/thing:1098784
Wondering with all these design changes and the modifications listed on this Forum if Lulzbot needs to do a complete re-design for the TAZ 6.
They went with much thicker rods and bearings on the mangrove prototype, and moved the Z rod back towards the X carriage, which should also work. Different paths. My approach costs more so their per machine cost would go up if they adopted that approach, which not everyone needs or would want to pay for.
http://devel.lulzbot.com/TAZ/Mangrove/photos/
Photos of the Mangrove Prototype from the Devel folder (NOT MY IMAGES OR MY MACHINE)
The reason why the middle of my glass bed was higher than the four corners is because the stock TAZ 4 corner clips over constrain the glass bed causing it to bulge in the center when using them to compensate for a mis-alignment between the two Y rods. My post explains how I fixed this:
https://forum.lulzbot.com/t/leveling-the-y-axis-getting-rid-of-high-low-spots/3706/2