Finally understanding bird wings - hopefully...

After the first animation test, all the extra bird anatomy study, more action analysis of folding wings and so on I still was puzzled about a very basic element of its structure... I'm not even too sure now what confused me the most, probably just the many angles and twists the wing makes to be folded, that made me overlook some things. In many drawings explaining the bird's skeleton it is visible that the arm is going down in an angle and up again. In the wing itself you don't really see this though. Now, after some more anatomy study I figured out that there is a muscle between the upper and lower arm that makes this invisible, and therefore confusing. Another reason why I couldn't figure out how it worked was that I was convinced about certain angles of things. I designed my wing so that the upper arm can fold backwards so the elbow will be at the back and wrist at the front, as it clearly happens when a bird folds its wings. I thought from here the feathers should keep facing down, although pivoting slightly more backwards as well, especially the primaries. I thought that if the elbow would face downwards and then be shifted backwards to be folded, that it couldn't work because the feathers would be horizontally suddenly. What I forgot to consider though is how every part would be shifted, as well as the body of the bird. The feathers actually have to be turned backwards, and because of how the shoulder joint moves and the body is positioned, everything then fits nicely in its place. This probably all sounds quite confusing and complicated when trying to explain it in text. That is how I felt trying to visualize it for myself, but not being able to fully analyse what was happening from video reference, not sure how to relate this to the anatomical drawings I had, and finally not able to perform the exact actions I could perceive with my armature so far. Until I finally got it after looking at the most simple diagram in a whiteboard animation video on youtube, aimed to explain bird flight understandable for kids.

Diagram how bird wings work. Source: http://www.youtube.com/watch?v=3So7OMwNgy8

Even though so simple, and many drawings I had seen so far should have explained the same concept, only now it made sense to me. I think possibly because it was the first clear top view showing the muscle and bone structure at once, but finally now I could understand how the wing should fold. I also see now that it probably had confused me from drawing my scale drawings from a front view, which would actually be the bottom of the bird and thinking that from there the wings should fold backwards, while actually it would look like they were folding sideways/up and down from the front, which in flight position would look like back and forwards. Oh well... what is back, side and front for a creature flying freely through the air? Clearly a lesson to define that better for myself next time... Anyway, this time I don't think I will have to re-design the entire wing, but can get away with just changing the direction of the hinge joint be re-soldering, and also adding an extra ball joint at the shoulder joint so it will be able to move more freely in all directions, which is quite important for this joint and I think was too limited with just one single ball joint...

I drew out the new adjustments in a new scale drawing, also incorporating other changes I've made along the way, and some new thoughts about the tail, where I'm now applying a similar mechanism as to the wing feathers. I made some pictures of the scale drawings, hopefully can make a better scan of it soon, but it hopefully makes some things clear for now.

Close up of the new wing design.

Full bird scale drawing - (not ultimate quality image).

The other elements except the adapted wing design which I incorporated in this new scale drawing are the new design for the leg attachment, as how I sketched it roughly some time ago. Also I skipped the k&s at the feet part of the legs. I thought I needed them to be able to separate the feet when casting them separate from the rest of the body, but now realized that I can still easily detach them, as it is just a matter of unscrewing the hinge joint... I changed the fanning mechanism for the tail as mentioned above and changed the direction of the joints for the middle body parts, which I had already figured out before and applied on the armature, but is still shown different in the previous drawing. I also thought again about the positioning and direction of the tail joints and decided that to have the most options with quick twists and bends I should have one joint facing sideways and one the other way around, so I can have both free movement up and down as well as sideways. I also worked out the facial mechanism on here this time, which I had only done roughly from one side before, and the different viewpoints only in a rough sketch. I changed some things from this sketch also, after studying the bird's skull anatomy more. I hope this design will make sense when I start building it... hopefully it will require less versions then the wing... So far it's designed to have an opening beak, also some up and down movement of the upper jaw, movable eyelids, an attachment point for tongue (will be wire in k&s) and then the joint to the neck. Or so is the plan right now at least...