>>81 Small pneumatic or hydraulic actuators are becoming the biggest issue I can find. The only small ones I seem to find have very limited pressure.

>>4275 Do you think something like a screw-drive & rack-drive linear actuator could serve in place of a hydraulic one Anon? There are several linear actuators in different sizes readily available. They are electrically-driven ofc. Some can produce quite a bit of force.

Apologies if this video has already been posted, but I found it fascinating and liberating to get a glimpse of how many experts and just how much testing it takes to get a humanoid robot working properly. Boston Dynamics employs around 300 people. In this video just over a dozen are shown. That should give an idea of just how much work goes into this. https://youtu.be/EezdinoG4mk

>>12473 Neat, thanks SophieDev. I feel reasonably confident saying I don't believe this video has been posted here before. Very interesting. I think it's absolutely amazing that we here are going to make better humanoid robots, on a shoe-string budget, from a small group of robowaifu-pioneering Anons. Ours will eventually be with men all over the world, while theirs will stay limited to govt. institutions only. Their multi-billion dollar conglomerate loaded with highly-paid, highly-educated engineers and designers (and absolutely drenched in the Globohomo Big Tech/Gov) vs. our merry little band of adventurers. Real life Robin Hood-tier stuff -- it will be glorious! :^) ONWARD ANONS!

>>81 Really cool cheap yet powerful stepper servo desigh. https://youtu.be/a1sZSIDxpfg

>>12473 >>12483 That does looks cool Anon. I'll download the video and have a look at it. Are there any other links to go along with it do you know (hackaday, instructables, etc)?

>>12488 --write-description option in youtube-dl will write the text coming with the video. Otherwise look at the page or in the app. I aw the video before, it's fascinating, but it might not be so great for a compliant humanoid robot, because these sun gears with high reduction ratio are not backdriveable. Otherwise it would fit better in the thread for actuators. This thread here seem to only exist for other robots than waifus. >>12473 Thanks, but this should be moved to >>374

>>17213 Posting in this thread now. I am attempting to make a silicone sensor while avoiding patent infringement. It appears that every possible patent is either expired, abandoned, or not applicable, so I'll proceed. So far I have created this giant mess. >pic related

I have a couple questions. 1. Would it be feasible to simulate muscles by twisting chords using electric motors to shorten them, or simply reeling up cable/chord? 2. If so, would pairs of these "muscles" working opposite each other, like biceps and triceps, be able to regenerate electricity as one pulled against the other to unwind/unreel against the opposing motor? Obviously there would still be energy loss but could you reduce the loss by using motors as regenerators? I'm asking because I had a weird dream after learning about Iceland's giant wooden puppet where there was a wooden doll that moved using twisting chords as muscles. It obviously looked feasible in my dream but my dreams are often retarded.

>>17429 I like your sketch Anon.

>1. Would it be feasible to simulate muscles by twisting chords using electric motors to shorten them, or simply reeling up cable/chord? Sounds doable. I've been trying my hand on a similar design. >2. If so, would pairs of these "muscles" working opposite each other, like biceps and triceps, be able to regenerate electricity as one pulled against the other to unwind/unreel against the opposing motor? Obviously there would still be energy loss but could you reduce the loss by using motors as regenerators? Wouldn't work. Any energy the relaxed engine would generate would be extra energy the engine under current would consume. The reason stuff like regenerative breaking works for EVs is because you're taking energy from the wheels while you don't want the wheels to spin.

>>17449 Thanks, maybe I'll learn to draw on the computer someday (I made this jupiter with a drawing pad a while back but, pencil to paper just feels more natural) Also helps to get the idea across quickly I used to be pretty good with Aldus Freehand back in the day but that was bought out by Adobe and I just hate the Illustrator Interface

I really feel this is one of the best, most simple joint mechanisms I've ever, ever seen. It's like human joints but in this case 3D printed. It's so simple I wonder I hadn't seen or thought of it myself. I feel like a fool for missing it. "Alternative to bearings for tiny robots" https://www.youtube.com/watch?v=TQiLLcumqDw This is incredibly good. I expect with some thinking you could make it move in two dimensions as that's what human joints knees do. It's so simple I'm terribly embarrassed for not seeing something like it. Has anyone else thought of this or am I the only one so foolish as to not see it as an obvious solution? It's an awful lot like this rope hinge I saved a drawing of but for some reason never equated it to robot joints.

Here's a book recommended by others on mechanical design constraints for accuracy and rigidity. Exact Constraint_ Machine Design Using Kinematic Processing (1999, ASME Press) - Douglass L. Blanding There's several links. At any one time many might not work so you just have to try them. https://libgen.gs/edition.php?id=138587005 A hackaday article on the subject https://hackaday.com/2019/09/11/books-you-should-read-exact-constraint-machine-design-using-kinematic-principles/

>>17473 Maybe this would work for you. Search "Wireless Optical Pocket Pen Mouse". Apparently they work on most surfaces. You don't need a tablet. I have one of these I got real cheap and haven't used it yet, I need to. I was thinking of drawing on my chest or stomach in a drawing program. Since it also works as a mouse it would be easy. Also I think people can very accurately move stuff around on their bodies so it would be natural. A lot easier than being forced into one position on a drawing tablet or hunching over a screen.

>>39724 That's really nice. I had thought about something like the rudder joint for knees or elbows before, but assumed it would not work well under compressive loads and would wear out quickly. A real skeletal joint is cushioned and lubricated with synovial fluid which prevents the surfaces from wearing too quickly and provides shock absorption. I'm curious how this would hold up. The design from the video might be better off not using a braided fishing line. I imagine it would start cutting into the channels in the printed joint pretty quickly.