Thing-O-Matic Z-axis rod stabilizers

When I built my TOM I included barrychuck's Z-stage mode http://www.thingiverse.com/thing:6184 The Z-axis platform was incredibly stable, but when I first started testing the stepper couldn't bring the platform all the way to the stop because the rods were binding. It runed out that the holes needed to be expanded on one side to allow the rods to sit where they needed to (the old over-constrained problem). Unfortunately the Z-axis was now able to move backwards and forward by over half a mm, mor