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.