Wow-I had no idea that's how long it's been since I last did anything to "old faithful" but so much has changed conceptually since then that entire plans and concepts have been reworked. In the interim, after Dirks "Bot Rod" controller and the hardened Y rails were installed she's just been humming away with a couple of idiosyncrocies that we got used to and compensated for.
But now the parts are rolling in and the rebuild is in progress. Possibly disappointing to some I decided finally to adhere to a modified version of the PRS design built on my PRT steel frame. So therefore the original angled steel x rails are going away and being replaced by a 1.5" x 1.5" 80/20 extrusion with a solid aluminum pillow block on it that is 2" x 3/4". The extra thickness from the PRS design is to allow for GW3 hardened rails from Superior Bearing and their correspondingly larger wheels. By pre-assembling the three components it should be stiff as a-----well you get the idea!
Leveling and making sure they are straight and parallel will be fairly straightforward. Original racks will be used but its time for pinions anyway. I got ShopBot standard endplates and an extrusion from Bosch for the Y. Again larger rails and wheels (already have the rails and wheels) and re-use the original pinion.
I also, given the parameters of the rest of the design, asked SB to sell me a y/z car with no motor or Spindle mounting plate and will, once it comes in and I verify some critical measurements, modify the wheel holes for the larger wheels or use a different size pillow block and make the adjustment there. For the aluminum spindle plate, I want to engineer my own for the final step in this stage which is to add a small spindle to the front of the Columbo mounted to an air activated linear slide for use as a drill.

The additional extrusion, thicker pillow bolock, and larger wheels on the x will raise the whole thing higher off the existing table height and my purpose of this is to raise the table base higher off the ground. The reason for the secondary spindle is to use it primarily as a drill and be able to rig up end panel boring. The overall goal is to end up with an easy 36" clearance off the ground to the top of the table surface so I can bore cab bottoms and stretchers for dowel construction. Also, of course, I can do all my Euro 5mm holes with the spindle/drill and cut faster and smoother with a 1/4" bit for back dado and parts cutout. I'll post some shots shortly and if any of you other PRT guys would be interested, I'll send you parts lists as it is updated. As things are being wrapped up I'll also put on the Columbo speed controller.
A special thanks to Ted who helped guide my needs and some explanations of the current engineering through SB.
I'm really going to enjoy bugging him when this is done to work out a functional toolchanger!!
It may be easier to sell my rig as is and just buy a new one but then there's no fun involved.