This is my Lego Mindstorms rendering of the giant robot (or mecha) 
that you can see in Matrix Reloaded and Revolutions, the Zion gatekeeper.

I always like robots like that since I saw Aliens II with the fight between Ripley in that yellow 
heavy lifter robot and the Queen.

Maybe someone could recognize that the principle of walking is "inspirated" to 
a design of Joe Nagata (Balancer C4).
I want to be honest: after many and many trials to do a turning biped that wasn't too heavy 
for "poor" lego motors or a bit good-looking, and after many and many failures,
I discovered this model searching in the unexplored universe of japanese Mindstorms pages.

The principle of Cog-Shifting is used also in some models of Kevin Clague but they're all too 
hard to build with simple Ris 2.0 kit(and I tried to build some, as Lego Maniac or Robo-Hominid 
and didn't work so well).

So I started developing this robot.I soon discovered that the mechanism of Balancer C4 wasn't good, 
and I modified deeply Leg structure.

Once obtained a stable and quick walking robot, I started adding the details after having 
taken documentation and many images from Matrix official Webpage,that has a section dedicated to APU:
 moveable arms,giant guns, the pilot cab, foot shape...
..and here's the result!

Hope You like it.

I will soon develop MLCAD instructions for my rendering of Matrix APU Gatekeeper.

For any feedback or comments please e-mail me at:

daniele_benedettelli@yahoo.it