I'm hoping to be able to fit a 12" tall part in the 770MX. Tormach sites the travel as 12.7, so given tool holding and tool height this makes it not seem possible. However, when I check their CAD model of the machine it appears that the distance from the bed to the bottom of the spindle is 15.075". And given that I doubt that the spindle nose can run all the way down into the bed, this seems to make sense. So the question is, could I machine the end of a 12" tall part in the 770MX?
Would have to be someone with a 770 to answer completely so they could measure but as you noted, Z travel is not the same as Z clearance. Arguably, that is another specification that Tormach probably ought to list on the details page of each machine.
These pictures are on my 770M+. My fixture plate is .7” thick so add that to the tape readings. Id say 14.5” from table to spindle nose, 12.7 to face of a TTS set screw holder. Hope it’s some help