[gt40]

Update:

I was able to rent a giant hoist for cheap and flipped the base and went to work removing the mold material. I even managed to alarm the wife dangling a 700 lb block over our driveway

I was really concerned whether all the work to use ground steel plates and pre-drill the mounting holes for the rails would be messed up by the epoxy. Good news, rails bolted up on a test fit and without even trying, are only .0242" off over the full length before even starting- casting does not seem to move ground steel plates. I had previously aligned things with a granite surface plate between the ground steel bars. It is a lot easier to mount things before you pour...

Couple of quick pics before I clean everything up this weekend.

I am happy things fit and the alignment works. Hopefully it will start to make sense because up till now, everything has been upside down for casting purposes...

3 foot base for the linear rail:

Attachment 274196

Mill base with servo and ballscrew sub bases + rail mounts:
Attachment 274198

Test fit: