Finalized wing design!

Below is the final scale drawing of the full puppet, with all the changes so far on the wing and the rest of the body combined and incorporated. We'll see how many times this still will change...

At least I think I am finally happy with the wing design... I completed the second wing using the new design, and it can move and fold in the right way now. The only issue I would have still with this design is perhaps that it moves too freely. As I changed the shoulder from one single ball joint plus a hinge joint into suddenly two ball joints + a double one at the elbow, there are many more ways it can move into, which could become confusing... But now the feather rods are on it already helps making it clearer and I think when everything is in place it should be ok. Compared to a wire armature it will still be more limited.

One other issue that came up this week was that I noticed that some of the bigger ball bearings I have been using - which were annealed by someone in the fabrication cente previously - were not entirely smooth anymore. They seem to have little dents and spots on the surface. I am afraid that it may have been caused by the annealing process, and maybe these steel balls got too hot or were too hot for too long. These balls are definitely softer then the smaller ones I annealed myself... They may be too soft. I'm not sure at the moment what I will do. I have already used the balls in several places. In the start I never noticed this damaged surface, but now every one I use seems to have it, and I can feel how it affects the smoothness of the movement in the joint. I am tempted to get new balls and anneal them myself and replace the non-smooth ones. But then it will delay things again... Maybe I will first do a proper animation test with this wing to see how bad it is.

Making new rods for the wing.

Making tiny screws even tinier. 

The new countersunk screws reduce a lot of volume from the previously sticking out screw heads. I will probably replace all of them in the other wing as well.

And here is the new wing all final and completed. Except the wire and fanning mechanism.

Really looking forward to completing the other wing in the same way now, to combine both and make an animation test with two wings...

New animation test

Still the old wing design, but with the wire extensions and possible solution for the fanning mechanism. In the mean time working on building the new wing design for the wing at the other side...

I had some doubts about the elastic band, but so far it works quite nice. Indeed it is a bit springy, but for the subtle movements needed in this part of the wing it works ok. I'm not sure though how it will work out in the hand part of the wing. Will have to just try it once I've got the new design for that finished for at least one wing. The wire works quite nice. I was thinking that the slightly thicker and therefore slightly tougher to animate wire would be nicer to work with, but actually I was more pleased with the thinner ones. Because it needs to be such subtle movement, it is easier to achieve this with the more flexible wire. But then, I don't want to move everything around when just slightly touching it... I will just have to play a bit around with different combinations I think to find what works best... Also it will take some more tests to find out what would be a good tension on the feather rods, so I don't accidentally knock them sideways, but still they are easy enough to move when pulling a feather. At the secondary feathers part where I already added the sewing elastic, it was hard to find a good balance where the rods were tightened enough to have some resistance against the elastic, but still loose enough to follow each other when pulling one.

During this test I also clearly noticed how my one ball joints are currently not working right and can not be tightened properly. The shoulder joint can in some positions just simply not carry all of the weight of the wing therefore, and so sometimes drops down, or makes other unwanted moves. That should all be resolved with the new design, hopefully...

Yep, now things are starting to move there is lots more to think about again and more problems to solve, as always...

extending feathers - trying a fanning solution

This weekend I had a go at extending the feather with wire how I originally planned it, poking the wire through the holes I made, and securing them with Polymorph (which should make it easier to replace a feather if necessary). Because I need the wire to be fairly thin, I tried strengthening it by twisting it together with copper wire. First I tried a double strand of really thin aluminium wire (can't remember the exact gauge, but much less then a mm) together with one or two strands of very thin copper wire (I only have some that is really thin). Then I didn't have any of the thin aluminium wire left, so tried it with one strand of 1mm aluminium wire with one strand of the thin copper wire. This actually seemed to get a nice balance between flexibility and strength, though I would have to test it to find out for sure.

I also bought some elastic band to try using this for the fanning mechanism. I used it double and sewed it around the flattened rods like previously with the stretchy fabric, but this time also using the holes I made to keep it at fixed at one place. I'm not fully satisfied with how it works, though it has some positive effect. At least the rods cannot move much further away from each other, and they are slightly pulling each other to follow, but not really as much as I had hoped. It does at the same time also create quite a bit of elastic tension, that might make it harder during animating to make subtle movements... I'm considering of I should for the secondary feathers just use a non-stretchy kind of fabric, as the feathers don't really have to move much separately from each other, but the primaries still need to...

Good advice & changing the design again

The first Monday after the break I went to Puppet's place in Bristol to meet Hanna Habermann, a very experienced stop motion armature and model maker. We talked about how to improve the shoulder joints, how to make better one ball joints and how I could simplify the end of the wing a bit to reduce weight and mass in the wing hand. The same day I quickly sketched a new plan from this and decided to start with this new plan for a new wing: it would not be much quicker to be 'changing' the first wing as there would still be a  lot of parts to make new. Because I have to present the project next week I thought it would be a good idea to have the old wing design still in its 'completed' form, to be able to show the comparison with the new plan. I hoped to have the main structure finished this week, but obviously things still always take longer than planned...

So, the new plan:

* change the shoulder joint(s) --> see scale drawing.
* Change elbow joint it to a double ball joint instead of hinge (and obviously still change the direction).
* Simplify the 'hand' of the wing: take one joint out at the end and make the second (now last) part longer (to have space still for all feather rods). Second part requires no extra joints in this way, and so will also be thinner.
* Change design of the single ball joints: have the screw separate from metal plates that 'fill' the gap distance between ball and plates. Or at least, have the metal plates not fully filling the gap: as the screw can not be tightened enough to tighten the joint.
*Don't file away from the rods when trying to create wider range of movement: this will weaken the rods. (I still stupidly made this mistake at some point this week... for a different reason) It is better to file away from the plates.
* Interesting to consider: looking at John Wright's ball joints, there seems to be one kind that has smaller holes as ball sockets, but therefore the balls can be much nearer the edge of the joint, or even sticking out: of course creating a lot of movement possibilities.

Although I have drawn the scale drawing only at the end of the week and used my rough sketches while building, I will share the scale drawing first now, as it will be clearer then my messy drawing... It will also be helpful for myself again while building, as I found this week that during building I got confused about the size of joints, which I think wouldn't have happened if I would have drawn it all out in scale...

(Final....?) new wing design

Even though I would think I would get a bit wiser every time, still I seem to be always doing things wrong first before getting them right... This week I started making the new one ball joints, needed for the shoulders and wrist joint. But, I made all three of them to be used with the small sizes steel balls, while I was planning to use the larger kind for the shoulder joints, which I think is important to have bigger and stronger for these important, much weight carrying joints. At least I still will be able to use the smaller joints for the otherside and possibly for part of the feet. But, now I had to make them again in the bigger variety. This took more time as I had to re-measure everything, etc. I had to file some more metal away after soldering but then put the screw that had been heated up back in again... apparently it had accidentally been annealed, and I messed up the screw head while trying to get it out... but this was also one of my new nicely fitting countersunk screws, so in no other way I could grab it. I tried destroying the screw by drilling through it up to the point where I would be able to take things apart again, but obviously it didn't work and I was destroying the whole joint. Alright... new attempt... In the mean time I figured out that for the other joint I had the holes lined up too closely to the edge and they would be too weak... So actually I should re-make this one as well... Very productive day...  I found luckily that I could re-use another joint made previously (not soldered together yet) for the hip joints, if I would just file away some metal around the screw area. But the other one I would have to re-make entirely.

Another mistake this week was where I tried to solder the rods onto the joints, put this time wanted to file away an area in the joint to have the rod laying in, which I had witnessed on one of Hanna's joints on Monday, but I didn't file away enough. I though it would be ok to file away just a little bit from the rod, but I had to file away more then I thought I would beforehand. It really doesn't look strong enough, I can even bend the metal there a bit too easily... so I think I definitely have to redo that part... For the other joint that would have to have a rod laying in it I could still not get it soldered after several attempts...

I also decided after making the elbow joint (a straightforward two ball joint) that I wanted to make it a bit smaller if possible. Ok, not the most time consuming thing next to the one ball joints, and can still use the larger one for the neck. All in all it didn't really get me up to speed this week though...

All the other parts for the wing are ready to be soldered together. I'm not sure if I will have much time to finish it still before the presentation though...

Lots of joints for the new wing, and lots that will not end up in the new wing.. too...

Final produce of this week, what will end up in the wing

(apart from re-making the rod part for the upper-arm probably...)

The one ball joints on this picture may look like they are still having a lot of metal around the part where the screw goes. I choose to start with longer plates that would cover the screw too, and then file enough away to still be able to tighten the screw enough, and hopefully it also makes the joint a bit stronger.

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...

anatomy study - notes to myself

These are just a collection of notes to myself from my further research into birds, and thoughts about them about how to or not to incorporate the knew knowledge into my armature design. Sometimes I get a bit carried away perhaps in details and subtleties which would in case this puppet would be for a specific production with a time/budget/etc. limit, and a certain purpose for the functioning of the puppet, not be necessary to figure out. In this case it was interesting and felt meaningful to learn a bit more about anatomy, to also get a better understanding of what I'm trying to achieve with the armature in general.

* primary feathers separate and turn, but secondary feathers don't.
Do they still pivot as a whole though? I designed my wing's  secondary feathers to be able to move and separate though I knew it would need less movement then the primaries, still it seemed necessary to have them able to move somehow during the folding of the wing. It is hard to exactly analyse it when watching moving birds as it is all so much hidden behind/underneath other feathers, etc.

* During a downstroke feathers overlap in such a way that they provide a firm boundary layer that air can't pass. Then, on the upstroke, feathers separate and the wing turns, so that air is flowing straight in between them. (youtube 'how bird wings work (compared to airplane wings) - smarter every day')
My wing design doesn't allow for real twisting of the feathers, at least, I think I would still be able to get enough of this subtle movement with the end of the feathers which will be wire, if necessary.

* Birds have a light tail (mainly feathers, only very short bone part), which makes that their center of gravity is in between the wings.
This is an interesting fact also to think about for the balance of the puppet... It is quite likely that for my puppet the center of gravity, and so also the puppet's balance, will be nearer the wings then the tail. Originally I had planned the rig attachment points to be nearer the hips, as I thought it would make the rig be less in the way with the flapping wings, and easier to hide. But this fact makes me consider again, if I shouldn't place it nearer the wings, so it works better with the balance of the puppet... Maybe I could attach it near the wings, but then let the rod/metal bar go in angle, leading first along the body more downwards, so the point where the rig will be actually attached can still be in a more convenient place to be out of sight. Perhaps I should just leave this decision to the last moment when I have most of the puppet done and can judge it more easily.

* Birds have a compact and centralized bodyplan around their centre of gravity between the wings. The main flight muscles are located at the body midline on the breastbone (which is why birds have large chests).
I'm just wondering now if I made the chest of my bird wide enough... I couldn't figure out exactly how the proportions work. I think together with the shoulders continuing into the wing parts I will have the right proportions, or something close hopefully. 

* Birds have large eyes, the largest part of the skull is reserved for the eye sockets.
Took this into consideration when designing the skull. I may need to make them slightly smaller in order to have the joint at the top of the head for the moving upper eye brows fit in nicely within the proportions without making the head too big.

* Looking at the chest of birds, their 'pectoral girdle' (part with collar bones and chest plate, but separate from rib cage) 'floats' within muscular support separate from the ribcage, so it can slide back and forth over the surface of the ribcage as the motions of flight demand. (Proctor & Lynch, 1993, manual of ornithology)
I found this to be a quite interesting discovery... Would this mean that I can actually never reproduce the full range of movement a wing/bird shoulder can make with my design so far? Would it mean that to actually achieve this it would be necessary to design some sort of chest structure that can move separately from the backbone/rib cage? Of course, at this point I would also need to reconsider what my actual aims are. Which is not to reproduce the exact anatomy and functioning of a real bird, but to make an animated character. In 9 out of 10 situations these sort of subtleties would definitely not be necessary in the puppet. Although my aims are here to create an accurate moving bird armature, this may be a step to skip, perhaps something to have fun with another time. I couldn't help though to have a little fun working out a possible solution, if my rough sketches make any sense:

* In a bird wing the elbow and wrist are in such a way connected that extending the elbow automatically also extends the wrist... This simplifies the co-ordination for the bird.
And also the co-ordination of the animator moving the bird... Good idea, nature is fascinating... But even more complex to build. I think for now I just need to learn coordinating the bird's wing in the right way when animating, but interesting to know, and perhaps consider such kind of mechanisms for any future armature projects...

* flight feathers are asymmetrical: the leading edge is narrower and less flexible the the trailing edge. This is to avoid twisting and damaging and ensures upward bending of the feather during the downstroke.
You can see this of course when looking at feathers, but good to be reminded of, also as it may help the actual functioning of the feathers as well if I design them like this for the puppet too.

Thinking about fanning mechanisms

For a long time I couldn't figure out the right way to go about the fanning mechanism, so I decided to study my new 'manual of Ornithology' a bit more to find out how it works in the real world...

In real bird anatomy, birds have individual muscles to each individual flight feather, which are pretty intricate and precise and lay on top of each other slightly. The feathers are attached to the 'postpotagium', which is a tough band of 'tendinous tissue' from the elbow to the wing tip. This postpotagium forms the leading edge of the wing and with its elastic strength 'keeps the flight feathers properly aligned and firmly attached to the wing skeleton.' (Proctor & Lynch, 1993).

I got a bit confused actually if the feathers are actually directly attached to the bones or if they are only held by this muscle structure. If I'm right they're still attached to the bones, but mostly held in place by the tendinous elastic structure. This is quite interesting, as so far I have been mainly considering moving mechanisms within the 'rigid' armature parts I have been making, while I had already been given the advice earlier to also consider the properties of soft materials having a role in the moving and functioning of the armature. I was considering to link up the feathers with metal rods, as I thought it would provide both a pull effect when opening the feathers, and push effect when closing the feathers. But, being rigid material it would have caused problems where the wing should fold, and also make the movement of the wing be quite limiting.
I did a test using stretchy fabric, quite crude for now, but the principle seems to work. I sewed it just around the feather rods, but when I get some holes in them I could fix it more to one place. I think I should try it with bandage instead of the legging stuff I used. Ideally something that is strong and a bit stiff, but still flexible enough... If I can find the right material I think it would work quite nicely... I will have to work out the right spacing between the feathers (which will be easier to judge when I've put the final extended feathers on) and then make sure the fabric can stretch the right amount so the feathers can open and close as far as they should and not further.

Fabric test for fan mechanism