[Animats]

Feetech is selling actuators which are mechanically R/C type servos, but have a bidirectional computer interface allowing the control computer to find out what's happening at the servo.[1] This isn't new; Dynamixel has been doing it for over a decade. But not at this price point. This Feetech servo is $17, while Dynamixel units start around $70 and go much higher.[2]

The parts list has "need to be strong" for many of the small parts, but they are 3D printed PLA plastic. That's the low end of 3D printing. None of the videos show the hand handling anything.

So this is really the proof of concept model. If there's enough interest, someone could make the parts by injection-molding of something better, such as polycarbonate or glass-filled nylon. The total plastic volume here is so tiny that the plastic cost is negligible, and there's no reason not to use a high-quality engineering plastic.

Nobody seems to do hobbyist injection molding much. TechShop had a desktop injection molding machine, the CNC milling machines to make molds, and even Autodesk Moldflow to design them. But nobody used those tools. A few university maker spaces have similar machines. Because most of the world's plastic stuff is made by injection molding.

[1] https://www.feetechrc.com/

[2] https://www.robotis.us/dynamixel/

[3] https://makerspace.engineering.nyu.edu/machines/pim/

[mionhe]

Mold design is still difficult when the parts aren't dead simple. The software I've seen is okay with the simple stuff, but once you get even a little more complex you have to understand simultaneously how to design good parts for molding and how to design good molds, both of which are heavily dependent on the type of plastic you're using and the size of the press you have access to. Not to mention how to machine good molds from metal, which is a challenge all on its own due to surface finish and tolerance requirements (and weird geometry that makes the CAM choke...)

In other words, we're not really there yet to bring that activity into the hobby realm. But I hope that we're not too far away.

[Animats]

They're little linkage parts, mostly flat.[1] Some of those holes are bearings. None of those parts are hard to make, but they need to be strong. They could be made by CNC machining, or in quantity by injection molding, or stamping. But tiny working parts in 3D printed PLA will be too flimsy for that hand to do much work.

Totally fixable problem. Then this hand can go to work.

If this thing catches on, someone might sell an upgrade kit with stronger parts. The designer is already considering a servo upgrade.

[1] https://github.com/pollen-robotics/AmazingHand/blob/main/ass...

[bigiain]

I haven't looked too carefully, but I suspect those "needs to be strong" parts could mostly be cnc machined with an inexpensive hobby CNC like a 3020, from aluminiumn sheet/bar stock.

[Animats]

That's what I was thinking, too. All but one of those parts can be easily milled from flat plate. The yoke end is a bit harder, but yoke ends are cheap standard parts and there's probably an off the shelf solution. The ball joints they use are standard R/C car parts. Those are available in in a stronger form, nylon with a brass ball, for EUR 0.53.[1] It won't be hard to strengthen this design so it can do useful work.

[1] https://toni-clark-shop.com/Ball-Joint-for-M2-and-M3

[contingencies]

Smiles from Detroit. I would look to press those parts, since most contact surfaces are potentially convex and variant-depth parts appear superfluous to requirements. With a shared punch and die you could pull the nest off a laser, press them all in parallel, and break them after the parallel press-forming. Should be cheaper than injection because the cycles can be faster, the material can be stronger, there's only one die, and the unload will be easier?

[Animats]

Yes. Here are very similar parts produced with a punch press.[1] In Silicon Valley. Or in China.[2]

This sort of thing is probably about $40,000 for the first part, $0.05 for each additional part. Designing and making the custom dies is expensive. Banging out the parts is cheap. Mass production works.

[1] https://www.petersenprecision.com/fine-blanking

[2] https://yonglihaomachinery.com/