Jojo-
I read your most recent post in the Huxley forum, and then looked at your older stuff (including this old post). I gave up on the TZ design, and am deriving my own from the kit and more modern components. I was able to purchase a gen7 electronics kit (it will do microstepping) from Traumflug, and an extruder kit from SeeMeCNC (it can use either 1.75mm or 3.0mm filament), both for less than the cost of a complete gen6 controller board.
My opinion is that the TZ Huxley has a usable frame and motors, it just needs to be reworked. TZ used 1/4" smooth rod; bearings for 1/4" smooth rod are ridiculously expensive. I am converting to 6mm rod, changing the electronics to gen7, and using a different extruder. A J-head extruder should work well with only small modifications to the original TZ Huxley X-carriage and still use the Bowden tube. But, I went with SeeMeCNC's "Steve's Extruder" for price and versatility.
My frame is together. I now need to cut the 6mm smooth rod to size and rebuild. 6mm smooth rod can be found for less than $5 for a 3 foot rod on Amazon or Ebay.
Good Luck! with your build. -Phuzzy