Thought I'd share this here.. While contemplating building a table from scratch earlier this year, we ran across an old Komatsu and decided to rebuild it instead.
The machine was in pretty rough shape when we got it; biggest issue was the rails which were seized, rusted, and deeply pitted. It was also missing the torch, servo drives, and other minor things, but I planned on going my own route there, so no big deal.
So far: stripped the machine down to the frame, cleaned/blasted all the parts, installed new bearings throughout, ordered new rails from Thompson, and started putting it all back together. The machine feels rigid enough at this point that I'm seriously considering mounting a spindle on the back side of the gantry and putting some t-slots down at the far end of the table for light machining.
The only thing that worries me about the servos is that the optical encoders are on the rack, not on the servos. Backlash seems to be practically nil, but has anyone successfully used encoders like this on a DIY setup before?