>I'm very concerned about mass
same, but in this case, I think the concern is minimal. Take the neck for example. I took it from Eva. It's already extremely strong, if using the six 9g mg90s which are only 1.8kgf cm @ 5V, it moves around 19 mg90s + silicone + plastic framework + other parts.
on top of this, i found these metal gear ds power 21g servos, they do about 4.2kgf cm @ 6V and are barely larger than a sg90/mg90s, (it's like mm difference). Way stronger, much quieter, tiny bit faster and far smoother running than real tower pro mg90s. the 21g are way too expensive however at 15 usd a servo.... but they are worth it on sale, i've seen em low as 4 usd. it's not so bad for the dof's that need strong forces
I started originally converting the Eva head from Colombia university to use all 21g's in the same locations, and keeping the 14 line pulling facial mechanism but to basically make it silent, stronger, and faster. but after some rudimentary testing i decided against it as the string system limits constructability far too much
instead im modifying Eva to use slotted or tracked pads connected to servo linkages. the pad contains a pattern of magnets to interface with internal skin magnets which are littered around the movement areas (cheek, lips, eyes, eyebrows). changing the pads shape and which internal magnets it interfaces with, allows for facial expression refinement and/or separate silicone faces using the same internal head.
the constrained magnetic pad system is how the best quality/life-like animatronics in film are done in my opinion. since the skin isn't attached directly to anything but by magnetic fields, the skin has a real physical compliance you can't get anywhere else.
>so I'm pursuing non-'traditional' manufacturing approaches & designs.
i am excited to see how it goes. the more experimentation the better imo.
>Good luck with your work!