The title ought to explain everything, in case you couldn't already tell what this is. I've had this idea floating about in my head for a while, and I even made some quick sketches on a tiny notepad, but I didn't get round to finally working on it until a few days ago.
No, I haven't actually been working on it for the past two weeks. In fact, four of the six components on the screen I made today: both of the arm sections and the two spaulders. Spaulders are shoulder armour, incidentally, but not to be confused with pauldrons, which surround the entire shoulder area. Spaulders are more like armoured epaulettes, and they pre-date pauldrons by at least three centuries. Anyway, the main elbow actuator is partially hidden behind one.
If I felt like making this mechanically accurate, then the cylinder and piston would be separate components, and the piston rod would be connected to the lever sticking out the back of the forearm.
While my usual excuse for not including every detail possible is "it won't show up on a 3d-printed model," that's not my reason this time. This time, I plan on trying some simple animation, and I don't want to have to worry about too many moving parts.
As it is, those spaulders aren't attached to anything, they're just sitting there. Lots of little things will have to get tweaked, but once I have those details taken care of, I'll be able to mirror the entire torso and then add the boiler to the back. Knowing me though, I'll probably kick that can down the road and work on the legs first.
What? Don't look at me like that!