I have been watching this thread for some time now. I am really excited about the concept of mechanoid units in ARMAII. To date, I have been closely watching the thread on the Armaholic forums (walker), and I hope there is some potential for such a creation for ARMA2.
Grub put it quite well in a previous comment. I remember OFP days, and the mechs that were created by modders were good, but they did not have articulated legs.
Does ARMA 2 have the same limitations?
Also, it would be nice to see the Robotech, Battletech and other mechs created for the game, but wouldn't a good first step be trying to design a mech that would be easily ported into the game as a first test design.
As I have said, on the Armaholic forum, someone is trying to create a mech, but instead of trying to create a completely new mech from scratch (or at least, from online designs), he/she is using what appears to be mech legs from Mechwarrior (madcat or vulture legs), and then using mashed parts already found in ARMA2 (cockpit from an apache plus chin turret 30mm cannon - maybe from PMC?, hellfire missiles, a M1A1 turrent, stock machine guns and grenade throwers).
It seems that this may be a pragmatic way to design a first mech: use as many existing parts and animations that already work in ARMA2 first, and only add necessary components that are not part of ARMA2 (legs and possible leg animations).
The mech design is reminiscent of a Battlefield 2142 walker (surprised no one has suggested one of those).
My two cents worth. This is a great idea, but I hope no one is biting off far more than they can chew for a first mech design.
Gaultesian the elder (aka Gaultesian)