Mocoff entry, starwars, see categories overkill, unique, unusual, robotic and mechanical.
About this creation
I haven't got a clue why anyone would use something like this in battle.
In fact, I haven't got a clue why anyone would use machines for their infantry.
Not worth the cost; men are cheaper. Not only do their parents pay taxes, they also pay for the maintanance and basic training of the trooper-to-be for the first thirty or so years.
The arm itself uses this little technique I figured out ages ago.
No, instructions will not be forthcoming. You can root through the Misc. folder for the original and its attached instructions yourself.