Proof of concept, not finale.
Automatic drill on wagon, 8x8 block drill head.
The signs will help you set up the mashine. If you want multiple you have to change the redstone links to the same block, there are 6 total. (2 on gantry extender, 1 on chaindrives top section, 1 near the cobble latch, 1 in drill head, 1 deep in the mashine)
Make sure that the latch on the last picture is on when assembling the train!!!
Second last picture is location of the latch you need to turn on/off depending on rotation.

Mining takes 1 hour, can be adjusted by selecting different amounts in the weighted ejetor, max is 30 (15 times) min 2 (1 time). (The dropper activates 2 times/cycle)