Quote Originally Posted by CNCMEBABY View Post
Been having a good measure up. With the saddle all the way back to the column there is 5mm of existing leadscrew nut covered up, this being the backlash adjusting part of the nut. This could be removed in the quest for the greatest X travel if required. Even without removing that 5mm of metal I reckon I can get 200mm of X travel including a nut on the end of the screw to prevent accidental over-travel. So plenty of travel for the 160mm table with a safety margin.
Having said the all above and read your plan for the antibacklash double 1204 nut, an easy double nut solution would appear to be to bore out the existing leadscrew nut as planned anyway for the first ball nut and mount another back to back with belvilles between to preload and use a couple of the mounting holes on the ballnut flanges between with one flange threaded and the other opened out slightly to use bolts to apply the preload. Then the space created by all that can be used to mount the stepper with the shaft facing out and on the left hand side of the saddle. I plan off-stands made from aluminium block for the spacing for the mounting plate off the front of the saddle.
I basically didn't like the amount of front overhang so wanted my saddle to move closer to the column.
I cut my base slot a bit, made some new bolt holes instead of using the large central one on the carriage.
Managed to get my saddle to move further back by 15mm. Overall I got 204mm movement from it with barely any extra overhang.

However. My throat is only 185mm but at least I don't need to hang off the front a mile. Later on I'll stick a 20mm spacer between the slide and head. Then I could use the whole 204mm.

This is on an Amat25lv similar to the Warco machine.