1:100 Zaku Kai - Orthographic design renderings
After creating version 2 of the rough design for the leg, I created a third and fourth version attempting to correct the main flaws in the earlier design: the low knee, a few inconsistencies between the front and side views, and so on. The third version was an improvement, and gave a nice, hefty look typical of some of the more curvaceous-looking renditions of the Zaku Kai, but it wasn't quite what I was looking for. I took some of its measurements to create the fourth rough design for the leg.
Key features of this version of the design:
Based on the version 4 diagram I created for the leg, I made this plan for how the knee joint would work. The Zaku Kai's knee armor moves with the knee joint, and in animation the armor generally always bridges the gap, no matter how far the leg bends. Interestingly, this is something Bandai seems to get backwards. Designs which should have this style knee, like the Kampfer and Zaku F2 wind up instead with the knee-plates attached to the lower leg. Designs which should not have this style knee, like the GP01, Strike Gundam, Gundam Mk. II, etc., are getting this as a bonus feature. Go figure.
Given my intention to replicate this style of knee, this design really only establishes two things. First, it gives me a real idea of how far the knee will actually be able to bend based on the placement of the axes and the shape of the armor. (About 120-130 degrees, give or take. And this without compromising the look of the design by taking notches out of the surrounding armor or changing angles.) Second, it establishes a plan for the shape of the knee armor and for how it will need to pivot with respect to the surrounding parts in order to stay in place. One pivot axis will be mounted on the knee joint itself, behind the top end of the knee armor. The other will have to be mounted somewhere in the lower leg, possibly with some kind of movable strut attachment. The plan is a compromise between how I want the knee to look when straight and how it should look when bent - ideally there would be little or no gap when the knee is bent, but in practice that's simply impossible, especially if I don't want the armor part to extend too far into the inside of the leg when the knee is straightened.