>>31403 >Capstan actuators I came online just to link this. You beat me too it. I second that this is a really great video and has a lot of big ideas. He talks about the mechanics of his drives in such a way that the info could be used for all sorts of drives. BTW the change in the look and operation of the website is...not good. It does not seem to function as well and is harder to read. When I go to references and hover over them, some show the reference, some don't. The old look and function was better...unless you can upload files now, in which case it's better to suffer. I notice this happens A LOT with software. They take something perfectly functional but has a sort of older look and spiff it up in the "new style", like Apples sort of flat candy look, and then it never works as good. It loses functionality and becomes harder to read and use. Don't get me started on Apple iphones. I have one, given to me, and it's a total usability piece of shit. There's all these beautiful icons that, have no explanation. There's all sorts of functions that if you get into them, there's no clear way to back up out of them and you can't read anything. What use is a device with no instructions but hieroglyphics that you have to go online in order to figure how to use it? Apple is the peacock tail of computers, the Thorstein Veblen of conspicuous consumption.

This is a first class link. It's a way to use low cost materials to make very powerful linear actuators. Something I've been talking about. I talked about using belts for windlasses but had not figured out how to recirculate the belts, and/or rope yet. I've been doing drawings of these but can't post drawings here so I gave up trying to describe them...Here's where I mentioned them >>31081 >>31087 My pitiful efforts have not come up with near, or even close, to the tidy package these guys have. I think there's some ways to optimize what they have done though their work is impressive . Don't miss this link. it's a great leap in linear actuator thinking that could lead to a good deal of progress. https://www.linearmotiontips.com/differential-windlass-drives-how-new-designs-work-for-linear-motion/ Why is this so good? I have talked before about using cycloids for bearings. Normal bearings are made of metal because the area they connect is so small. Therefore you need a super strong well machined surface. Big $$$$$. But if you can spread the forces out plenty of plastics and especially fiber reinforced plastics work not only as well but better because of some of the springiness of the material allows for some give. Meaning less likely to break. Manufacturing these sort of things could be easily done with a simple vacuum infusion set up with an accurate, but easily made die/mold for the form. Big time DIY.

>>31576 They have a great video here. It reiterates why I complain about hydraulics and the losses(though I have some changes in mind about this because I think hydraulics might be easier to mass produce.) https://youtu.be/Rp_kmhphpyk It kills me that I was so close to something like what they have, but too late.

>>31576 >https://www.linearmotiontips.com/differential-windlass-drives-how-new-designs-work-for-linear-motion/ Excellent information Anon. I've tried designing low-friction systems that follow similar concepts -- yet remain low-cost. (Faux) silk ribbons are a reasonably-good cording choice IMO; strong, light, resilent, and slippery as an eel ! :D Thanks Grommet. Another great post. Cheers. :^) >=== -minor edit

>>31577 You can just use Chinese/differential windlasses. They only own patents for over complicated versions. Vidrel has all the information you need. https://www.youtube.com/watch?v=zfaeVPQO2ek

>>31624 Neat! This gentleman is a wellspring of old lore. Thanks, Anon. Also, be sure to check out the next, related video of that playlist: https://www.youtube.com/watch?v=OXzGSB4i1UU&list=PL6HIFled82YVpPbRjhcfF7z5R-tmTAJiE&index=8

>>31403 >>31432 >Capstan actuator/drive Seems we all are in the recommendation algorithm loop for this. It seems pretty useful but I wonder what the ideal "rope" would be whether it is steel cable or nylon rope or maybe even steel chains.

>>31707 I was looking at 3D metal printing and ran across this. https://www.youtube.com/watch?v=Js3bJ1B8ySM It seems that "per weight( or specific strength), regular plastic is not so damn weak. A 4gm test piece of PLA+ held 154 lbs. before it broke. And most of the weight was the ends of the test piece. >I wonder what the ideal "rope" would be whether it is steel cable or nylon rope or maybe even steel chains. Strongest would be 4mm dyneema or UHMWPE Braided Cord(same thing). WOW! Black 1/8"(Dia.) 2200Lb $37.95 100 ft. Nylon would likely be WAY cheaper and good enough. The chain I reference below is less strong and more expensive but...using metal chain like this can be used as part of a motor, #35 x 100 ft. Zinc Plated Steel $48.47 Working load limit of 106 lb.[actually price per strength is not so bad. This is "working load" which is way less than breaking load]. The other ropes are shown, breaking load. https://www.homedepot.com/p/Everbilt-35-x-100-ft-Zinc-Plated-Steel-Sash-Chain-806600/203958837 Another picture of copper coated, https://cdn11.bigcommerce.com/s-e7e21/images/stencil/1200x1800/products/127986/328788/apii9rkiv__89322.1592325935.jpg?c=2 I was surprised by the low cost of UHMWPE. In the past I thought that the price for UHMWPE was really high. It must have come down or I didn't closely compare. Maybe the Chinese are driving the price down. I think the cheap price for UHMWPE is because it's actually polyethylene. The same stuff everything is made of. Plastic bags etc. But if I understand correctly, they make the poly chains much when they make the new plastic. They stretch them to align with each other. Now the long chain plastic molecular links are not extremely strong individually but they are so long that there are a huge amount of them and all the little molecular bonds add up to a really strong plastic. The big problem with this stuff is it's hard to tie knots or to connect it because it's so slippery but I'm sure that can be over come. Another problem is this stuff has NO stretch at all. So it would make poor tendons which need some stretch. They have nylon 1000 lbs. paracord [they say 1000 but...]for less which might be fine and stretches. $8.99 100 ft.

>>31403 >Capstan actuators are cool, quiet, and efficient! Github: https://github.com/aaedmusa/Capstan-Drive Yes, very interesting. But I guess this will only be usable in some places, since it is big. I also found this here. Since I always had the idea of springs or stretching rope for muscles in the back of my mind, I think this idea here is something to also keep in mind. Maybe for making the waifu jump in some cases, or for some fast movement. A loaded spring could be blocked with a solenoid for a little while. >Grasshopper leg explained https://youtu.be/MwIBTbumd1Q >>31576 >Chinese/differential windlasses >>31629 > Old lore, The differential chain hoist. Very interesting. Thanks.

Just as a thought exercise or a benchmark on how much force you can get with electromagnets, which also means EMF motors. I was looking at high power ceramic magnets and they had electromagnets mixed up with them in the site. Here's a couple with prices, Electromagnet with 1/4 in. Mounting Hole - 12V DC/3.3W - 1-9/16 in. dia x 1-9/16 in. thick - 59.54lbs Pull EM4441M6 Now From $20.99 Was: $25.20 | Save: $4.21 Electromagnet with M5 Mounting Hole - 24V/10W) - 110.25lbs Pull - 1-7/8 in. dia x 1-1/16 in. thick EM502027M5 From $35.28 https://www.first4magnets.com/us/44lbs-110lbs-t49 10W - 110.25lbs Pull That's a hell of a lot of force from a small amount of power. Now to be realistic this force is the attraction, likely, to a thick steel plate but a properly designed motor would have some of the same attributes in terms of force per watts, per weight, per size. Makes a good rule of thumb comparison. Say you shave off 20% and you could likely get these figures with a well designed motor, actuator. So with say...40W we could get somewhere around 400 lbs,. of force. That's what I'm looking for. At that level it could easily pick up most humans. We can use this to plan wire size. 40W/48 volts = 0.83 Amps Not a lot. Chart. https://2.bp.blogspot.com/-9TdTKLNaH_0/WBsh3YchzjI/AAAAAAAAEfU/BQZ9Nqc8IU80GFdBVoQgy0zwOEzWyI7tQCLcB/s640/wire-gauge-ampacity-chart_460534.jpg 26 gauge wire will handle 1.3A enclosed. So it would be better than needed. I see 250 feet with silicon jacket for $18.48 USD. I also see 1.000 foot, surely enough for more than one waifu, 28 gauge for $39.98. Could cost you a little, maybe even twice as much if you buy from US or European sources. (don't know just speculating) Chinese wire, maybe good, maybe not. Cheap but a risk. Figure in troubleshooting time if they send you bad wire and it may be worth twice the cost for Europe or US wire. Make sure, silicon jacket AND machine wire spec. Other jackets may be just as good but I do know silicon would be up to the job. More research may find stuff cheaper that will work but silicon jacket is the safe bet. Machine wire is specifically made to handle movement and vibration. Otherwise the wire will break through work hardening as it moves. I did these for myself to nail down some rough cost guidelines and thought I would comment it here. Maybe it will help others.

>>31961 >High pull force magnets It's important to remember you are given the force at contact with steel. Which is pretty close to your guess. >400+ pounds of force at 40W You can indeed get tremendous forces at low currents. The problem is this requires the steel to be touching the electromagnet. Which, would prohibit rotation. Using many of them to create a rotating magnetic field would be more expensive, heavier, and larger than a comparable purpose built motor. What I think you're going towards are solenoids. They will provide the forces at low power you are looking for. This provides you with 2 problems to solve. 1. How will you control the stroke to fit into your needs? 2. How will you retain position without the solenoid becoming a heater? Some helpful links; https://science.howstuffworks.com/solenoid.htm https://audioxpress.com/article/voice-coils-a-tutorial https://www.machinedesign.com/mechanical-motion-systems/article/21836669/what-is-a-voice-coil-actuator

>>31961 >>31978 Thanks, Anons.

>>31978 Great graph. Very informative. >What I think you're going towards are solenoids No I was just showing a general rule of thumb of what sort of forces we could get for what power. I do realize the force they are quoting is directly connected to a thick steel plate. A thin one would not show this sort of force. it would have to be thick. But I have brainstormed solenoid type actuators here. >>9984 >>10002 It's a terribly retarded idea, and likely noisy, but...really cheap and simple.

> (actuator/joint-braking convo-related : >>32321, ...) >=== -minor edit

Potentially a breakthrough increase in motor-efficiency design. https://www.youtube.com/watch?v=JGdIZF5gE7I

>>32828 Interesting, thanks. I kinda thought this was just some AI generated BS, after looking at the thumbnail, so I hesitated watching the video. There's too much BS on YouTube and I on the other hand tend to fall too much for drama. Anyways, there's also some guy providing special software for making motors, I saw him on Reddit or Twitter and YouTube, but don't remember the name. I thought this would just be another layer of difficulty and rabbit hole, but maybe we'll get to this one day. He exists, and some people are interested in it. One thing that interested me before was the alternative of motors without rare earth magnets, or perma magnets in general, since these could get rare or would be a possible vector to ban people from building robots. Good to see that there might now even be alternatives to these induction motors. But this is also just something to keep in mind, doesn't help us right now to get things done. I don't see anyone of us doing this anytime soon. These seem to be build for electric vehicles for now, and the one shown as a possible product weights 39kg (86 pounds). We certainly should keep an eye on it, maybe it will be available as a product for a scooter or paid printing services could deliver something like it one day. Though, then again, the video also says that this is "competitive" engineering and might not be economically feasible. And it's a prototype and hasn't really been tested. So, not really BS, but most likely also not useful anytime soon. Just want to throw in some keywords here for later search: copper printing, 3D printed copper coils, laser powder bed 3D printing, multi-material powder printing

>>32910 >since these could get rare or would be a possible vector to ban people from building robots Great point, NoidoDev. Yes, I've thought about this exact topic many times, trying to find a way around it. Of course, I'm far less concerned about the Chinese resisting robowaifus (also the biggest refiner of rare-earth metals, obvs), and far more concerned about the Globohomo we here in the West are all assaulted by. The troon-thug cycle is far more a personal pressing threat to us all, than w/e Dr. Lee or Mr. Chang think about us. <---> But REM aside, just the cost of the motors assemblies themselves is prohibitive, thus why I was exploring devising our own, opensauce, motor winding systems.

Came across an interesting actuator design on youtube: A 2-stage gearset with a 21.3/1 reduction ratio. Aside from the power he's able to generate with it, he mentions something that I never thought of, that being backdrivability being used to sense external forces applied to the robot. The only glaring issue I can see is it's large size. On a completely function oriented machine like what he's making that's no issue. But on a robowaifu? I'm not sure how easily they can be hidden. https://www.youtube.com/watch?v=v3g2VdduawI

>>33233 Excellent actuator, backdrivability is indeed important for man machine relations. In this case, it appears they are using current sensing to determine position and external torques being applied to the motor. I base this on a lack of light leakage, or dark spots indicating a magnet under the thin white plastic. The B-G431B-ESC1 (https://www.st.com/en/evaluation-tools/b-g431b-esc1.html) would be an ideal ESC to use for this due to its low cost and having plenty of support online. As for the gears, replacing them with eccentic cylcoidal mechanisms would allow for a smaller, more efficient system. Still would recommend adding some sort of grease or lubricant to reduce wear, heat, and drastically increase usable lifespan for the actuator.

Anon-designed, custom servo motor control board. Very cool! :^) https://www.youtube.com/watch?v=DDDD7iGMljw

Remarkably good linear actuator. I'm contemplating reworking my thigh/knee/shin complex to use these instead now. https://www.youtube.com/watch?v=bQl6gj_6oa8

>>33282 Update to the actual, working, prototype Jugglebot. Very entertaining Anon, and impressive project progress. https://www.youtube.com/watch?v=CiorGYCZOgk&list=PLe8shy-tVWtqXVAZ4kuTlRkpZlsaZRHAK&index=70 This guy should get to know /hover/ !! :^) https://trashchan.xyz/server/thread/4.html >=== -sp edit

>>33282 >>33283 What's especially-intriguing to me about this Anon's project is that from the outset, his goals for it (ie, womping teh heckin' heck out of those jugglin' balls!111) quite naturally channeled his design decisions into much of the same solutionspace that we here ourselves also need to manage arriving at (cf. >>33356, et al). Key above all others, was his (apparent) innate recognition that mass is everything : ( >>4313 ). His choices based on this single constraint (ie; REDUCE INERTIAL MOMENTS AT ALL COSTS -- aka 'thrown weight') led directly to his distinctly-successful linear actuator design. This success, in turn, directly enabled the success of his agile Stewart Platform approach. While this complex arrangement design won't likely be of much use to us for robowaifus beyond possibly the torso-actuation + collarbone/neck/skull -actuation complexes -- the basic linear actuator's low-mass & responsiveness & (relatively) low-cost & reasonable-manufacturability make it quite-well-suited to robowaifu skeletal actuation in general. Further, the fact that probably >95% of the actuator's mass is concentrated on one end (and therefore able to be arranged proximally to the robowaifu's main-torso monocoques -- thereby further reducing thrown weight+helping to coalesce dynamic central-mass around the pelvic volume geometric pivot-point) is just a big, energy-saving cherry on the top! :^) <---> >tl;dr This must be a kind of joke being played on me rn that I only just now discovered this project. It would have shortened much of the time for my design explorations thus far. Maybe I just needed a little """reminder""" to remember that 'The real prize was the friends we made along the wayduring this long & arduous, monumental climb' , hehe! Actually, I honestly do thank you for everything you've done for me, dearest Lord Jesus!! :D <insert: some_days_you_just_feel_like_getting_out_of_bed.jpg> >=== -prose edit -add crosslink

>>33283 That is one impressive actuator.

>>33315 I'm planning to totally steal his stuff for our waifus. Exploring the options now. Mine should be lighter than his. I wonder what he would think of robowaifus haha. :D

>>33320 BTW, look at this actuator detail I dreamed up a while ago. >>12941 See the motor like his. A little different. There's a cone on the end of the actuator. The pulley to the right has a spring pulling it down. "If" a large force is needed then the pulley is pulled towards the smaller end of the cone on the motor. Giving you a better force, but the motor has to spin more. Auto transmission based on spring constant. His is much better for linear but I think the one I dreamed up would be good for waifus. If I was going to improve his for linear actuators, I would make it like a scissor jack. I think it would be much stronger. Possibly the sprung weight would be higher but maybe not because the scissor mechanism would be lighter and far less cost as a truss wouldn't need carbon fiber which is outrageous in cost. You could use fiberglass. Carbon way more expensive but it is super stiff.

>>33364 >this actuator detail I dreamed up a while ago. Nice work! You're really ahead of the curve with that one, Grommet. :^) >this was my response back then, BTW : ( >>12943 ). I may say I loved the 'CVT power-pull' on that little bike -- smooth as silk. :) I like your ideas about further refinements to your design. We here could certainly all use such a device. To my own thinking, Jugglebot Anon's design is a great (& simple) start, and it's linear-actuation certainly works well with my tiny-mass/high-leverage-coefficient skeletal limb designs. Regardless, keep those ideas flowing Anon. Together, We're All Gonna Make It. Cheers. :^) >=== -prose edit

I was looking at gears and files I had saved and ran across an interesting very high reduction gear system that I had forgot about. A bit difficult to understand. It uses the teeth of gears very finely offset with a separate track to wedge them into place. So two tracks have teeth(gear teeth) slightly offset, and a third forces a flexible wedge into them to align them. Moving the track forward. It's primarily used in motors. The Moon rover used one to drive the wheels. They supposedly are very efficient, have very little to no backlash and compact with high gear ratios. Here's a link to video that shows how they work. Notice the linear example he shows first. Maybe, not sure, this could be set up as an actuator with the "flex spline" being activated or pushed into the two active geared splines by a roller that moves up the linear two splines. For testing these could be 3D printed with two solid gears(splines) and one flexible made with TPU or whatever. https://www.youtube.com/watch?v=7QidXf9pFYo https://www.engineeringclicks.com/harmonic-drive/ In some ways, kinds, sorts, this is like the idea I had to use a ball screw and one solenoid to scoot the balls up one at a time. >>9984 I wonder if you could do the same with these two wedge shaped gears and have a single edge move the parts just like the "flex spline" moves the rotary motion of the gear train in a harmonic drive?? Another way of looking at designs somewhat similar is the action of a farm jack.

>>33531 Uh oh, I'm repeating myself. Sigh...

Fridman interview, Electric vs. Hydraulic actuation: https://www.youtube.com/watch?v=6r6KPuJ689o

>>33990 Nice video. I hate hydraulics but...I could see with some sort of new valve design how it could be super cheap and easy to manufacture.

I'm finally writing down the plan for each movement, using the pattern from here. While listening to some soundtracks to prevent me from getting bored and going back to do something else. This plan might need several iterations, and this is just work in progress. I kept thinking about these things, but then forgetting it again, I really have to write it down. I think it's quite general, so it can fit into the thread here, but maybe it's time to make my own. - release and nudge means having a (soft) lock holding something in place, releasing it and just have some actuator the part into falling into one direction till it is stopped. - I think each movement will need more than one actuator. We need something for slow and something for fast movements. The latter might be limited in range. The precision might also vary. - loaded springs mean springs that are loaded and blocked by a solenoid and can be released to support or carry out a movement. > Head and Neck: > 1. Neck flexion and extension (forward and backward movement) - fast short movement: - forward: release and nudge, maybe multiple stages - solenoid, with a spring? - backward: twisted flexible string in the neck - maybe additional servo somewhere in the neck - slow full movement: - forward: flexible string in the neck slowly released - maybe one servo to pull forward at the end - backward: string in the neck fully twisted and maybe blocked > 1. Neck lateral flexion (side-to-side movement) - one servo for side rolling, two solenoids to lock - fast short movement: nudge and fall down, spring support back up - slow full movement: more in the shoulders > 2. Neck rotation (turning left and right) - fast full movement: maybe at least one loaded spring - slow full movement: more in the shoulders - regular fast movement: at least one fast spine servo, bones connected

>>34130 POTD I'll look into following your lead with my own software functions in my code, NoidoDev. Keep up the great work! Cheers. :^)

I'm sure everyone knows about those carbon nanotube muscles that were ten years away fifteen years ago, but has anyone tried just building the same thing using commercial carbon fiber? It's almost as strong and almost as conductive, so I don't see why it couldn't be used in the same way. https://www.youtube.com/watch?v=n-zXKrBoJGs

>>34133 >carbon nanotube muscles Interesting. Well, how do they work? Has anyone made them outside of a big lab? I looked a bit into it for a moment: >Rotary motors of conventional design can be rather complex and are therefore difficult to miniaturize; previous carbon nanotube artificial muscles provide contraction and bending, but not rotation. We show that an electrolyte-filled twist-spun carbon nanotube yarn, much thinner than a human hair, functions as a torsional artificial muscle in a simple three-electrode electrochemical system, providing a reversible 15,000° rotation and 590 revolutions per minute. A hydrostatic actuation mechanism, as seen in muscular hydrostats in nature, explains the simultaneous occurrence of lengthwise contraction and torsional rotation during the yarn volume increase caused by electrochemical double-layer charge injection. The use of a torsional yarn muscle as a mixer for a fluidic chip is demonstrated. https://www.science.org/doi/10.1126/science.1211220 >Improved electrically powered artificial muscles are needed for generating force, moving objects, and accomplishing work. Carbon nanotube aerogel sheets are the sole component of new artificial muscles that provide giant elongations and elongation rates of 220% and (3.7 × 104)% per second, respectively, at operating temperatures from 80 to 1900 kelvin. These solid-state–fabricated sheets are enthalpic rubbers having gaslike density and specific strength in one direction higher than those of steel plate. Actuation decreases nanotube aerogel density and can be permanently frozen for such device applications as transparent electrodes. Poisson's ratios reach 15, a factor of 30 higher than for conventional rubbers. These giant Poisson's ratios explain the observed opposite sign of width and length actuation and result in rare properties: negative linear compressibility and stretch densification. https://www.science.org/doi/10.1126/science.1168312 >Carbon aerogels are elastic, mechanically robust and fatigue resistant and are known for their promising applications in the fields of soft robotics, pressure sensors etc. However, these aerogels are generally fragile and/or easily deformable, which limits their applications. Here, we report a synthesis strategy for fabricating highly compressible and fatigue-resistant aerogels by assembling interconnected carbon tubes. The carbon tube aerogels demonstrate near-zero Poisson’s ratio, exhibit a maximum strength over 20 MPa and a completely recoverable strain up to 99%. They show high fatigue resistance (less than 1.5% permanent degradation after 1000 cycles at 99% strain) and are thermally stable up to 2500 °C in an Ar atmosphere. Additionally, they possess tunable conductivity and electromagnetic shielding. The combined mechanical and multi-functional properties offer an attractive material for the use in harsh environments. https://www.nature.com/articles/s41467-023-38664-6 Buying the ingredients might be possible: https://www.acsmaterial.com/carbon-nanotube-sponges.html - But it's around US$200.- per gram. Single-Walled Carbon Nanotube Paper: $300.00

>>34139 My understanding is that it contracts because the fibers repel each other when they're charged to a high voltage. Back when it was announced they were talking about it being 20000 times stronger than natural muscles, but after some initial excitement there were no further announcements and people just forgot about it. While I don't know why it was dropped, I'm guessing it's because they never found a cheap way to produce the fibers, which is why I think carbon fiber might be the answer: it's not as strong as carbon nanotubes but it's probably strong enough and $200 will buy you 4lb of it. https://acpcomposites.com/shop/fabrics/tow-cord/carbon-fiber-tow The high voltage may pose a problem but I think it could be safely contained using a PTFE sleeve wrapped in foil. PTFE can comfortably handle at least 10kV/mm, and if it wears too thin in one spot then the fibers would touch the foil and short to ground.

>>34141 >expensive and high voltage Too bad. If it's expensive but fast it would be interesting for small movements, like in the face or maybe the hands. But I wouldn't like high voltage there. >I think carbon fiber might be the answer Well, I'd like to see someone experimenting with it. Maybe try to convince people outside of this board. We simply aren't that many people. Or add a task to our "Stop Lurking" thread here: >>20037

>>34132 >I'll look into following your lead with my own software functions in my code Thanks for working on this. I hope you make this into modules which can be easily adapted to something. I could also imagine that I'd like to run the code for the actual movement decentralized on Arduinos. The realization and the command to do a set of movements, the motion planning, and the execution of the commands to the servo might be on different hardware (SBCs and controllers). Some notes from expanding >>34130 >Problems to solve - linear actuator, but hold in place by solenoid blockage - twisted string, freezing with solenoid blockage - solenoid holder, but with a limiter - adjustable spring mechanisms >General: - Any movement that happens automatically through gravity should have a spring that can be loaded and locked. Then the reverse movement is supported by a release of the spring(s). Compliance can be somewhat archived by making these movements not too strong or by using a brake mechanism. Precision isn't important. - Repetitive movement like some dancing moves should also be covered with spring mechanisms. Adjustable by moving the spring linearly a bit.

>>34130 >>34152 Seems that you're interested in dynamic motion with brakes for control. Check out passive dynamic robotics. There's much that can be done using gravity and precise control. https://journals.sagepub.com/doi/full/10.1177/1687814015620967

>>34157 >passive dynamic robotics Thanks. That's certainly interesting. Though, I'm not very focused on walking, and I'm not sure how much this will add to make something walk. I meant it more general. Anyways, it's probably good to keep these ideas about walking in mind right from the start.

>>34152 I might draw and scan something tomorrow. But here are the descriptions. We have to keep such concepts in mind, to design a good system. Not just relying on regular servos. > linear actuator, but hold in place by solenoid blockage Linear actuator in a tube. It being up is holding something. It can move down again relatively slowly (and noisy). But can release faster by "falling down" the tube after a solenoid blocking shaft is released sideways. Of course, another mechanism would need to get the linear actuator up to the neutral position again. > twisted string, freezing with solenoid blockage Some holding mechanism holding the twisted string in that position. The solenoid opened during the twisting of the string with a servo, it goes back to the unpowered position which holds the twisted string in place. > solenoid holder, but with a limiter Just adding a more flexible material in front of the shaft. This softer part is being used to block something. But it can give in, if a certain amount of force is used. The solenoid shaft itself is way stronger. > adjustable spring mechanisms Idk. I'm sure this is a solved issue. Some mountain-bikes have adjustable shock absorbers. I want something like that and smaller variants, but with a small servo that does the adjustment.

>>34130 These are the notes for now. Just posting this as a backup and if somebody wants to think about it himself. I have to think more about the details over time. > Head and Neck, 7 disks: 1. Neck flexion and extension (forward and backward movement) - fast short movement: - forward: release (5) and nudge (1), maybe multiple stages (6) - solenoid, with a spring? Adjustable (3) - backward: twisted flexible string in the neck (2) - maybe additional servo somewhere in the neck (1) - slow full movement: - forward: flexible string in the neck slowly released (2) - maybe one servo to pull forward at the end (1) - backward: string in the neck fully twisted and maybe blocked (2) (4) 2. Neck lateral flexion (side-to-side movement) - servos for side rolling, two solenoids to lock - fast short movement: nudge and fall down, spring support back up - slow full movement: maybe servos in the disks 3. Neck rotation (turning left and right) - fast full movement: maybe at least one loaded spring - slow full movement: flexible twisted strings in the shoulders - regular fast movement: at least one fast spine servo, bones connected > Upper Body: 1. Shoulder flexion and extension (raising and lowering the arm) - Maybe a fast linear actuators - Loaded spring actuators - Twisted string actuators for regular movement - Servos for precision movement 2. Shoulder abduction and adduction (arm away from or towards the body) - servos in the shoulder and chest (breast) - maybe solenoid under the armpits - maybe loaded spring actuator under the armpits 3. Shoulder internal and external rotation (rotating the arm inward or outward) - one servo per shoulder 4. Elbow flexion and extension (bending and straightening the arm) - fast movement: small servo in the elbow - maybe additional twisted string actuator - additional bending spring actuator >>13711 - slow full movement: windlass pulley in the arm 5. Forearm pronation and supination (rotating the forearm to face down or up) - one servo per shoulder - rotation within the (lower) arms with servos >>14474 - maybe also electro-magnets in the two bones (fast, no load) 6. Wrist flexion and extension (bending the wrist up or down) - actuators in the lower arm ... 7. Wrist radial and ulnar deviation (bending the wrist towards the thumb or little finger) - actuators in the lower arm ... 8. Hand and finger movements, including individual finger flexion and extension, abduction and adduction, and thumb opposition >>4577 This is going to be a topic on it's own. Mostly actuators in the lower arm and some small ones in the palm. - palm bending: ... - group of finger bending, and opposite direction: ... - individual finger bending: ... - finger abduction and adduction: ... > Spine and Torso: 1. Spinal flexion and extension (forward and backward bending), 5 disks - small servos in some spinal bones - servos with (twisted, flexible) strings in the hip area and lower torso 2. Spinal lateral flexion (side bending), 5 disks - small servos in some spinal bones - servos with (twisted, flexible) strings in the hip area and lower torso - the water- or airbag holding mechanism 3. Spinal rotation (twisting), 12 - small servos in some spinal bones - pulling the other bones with it if it rotates to a certain extent - servos with (twisted, flexible) strings in the hip area and lower torso 4. Pelvic tilt (tilting the pelvis forward or backward) - maybe one servo > Lower Body >>237: 1. Hip flexion and extension (lifting the leg forward or backward) - huge servos in the hip areas, maybe Capstan actuators - one servo in the back of the hip - to string-pull each leg in series just enough to walk - should probably also bend the knee a bit - string based actuators in the thighs, switching string idea 2. Hip abduction and adduction (moving the leg away from or towards the midline) - rotating uneven disk to push it outwards while normally moving inwards - maybe additional pull outwards for faster movement 3. Hip internal and external rotation (rotating the leg inward or outward) - servos in the thighs 4. Knee flexion and extension (bending and straightening the leg) - servos in the knees - one servo in the back of the hip - to string-pull each leg in series just enough to walk - same as for hip flexion and extension - string based actuators in the thighs 5. Ankle dorsiflexion and plantarflexion (pointing the foot up or down) - servos in the ankle - maybe additional loaded spring and solenoid in the lower legs - ideally a way to load a spring mechanism when landing with the heel 6. Ankle inversion and eversion (turning the foot inward or outward) - servos in the ankle and lower leg - some string based actuators - maybe additional loaded spring and solenoid in the lower legs 7. Toe movements, including flexion and extension, abduction and adduction - mostly all moving together - servos for slow and solenoids for fast movement - maybe additional spring and release mechanism for running

>>34152 >Thanks for working on this. >I hope you make this into modules which can be easily adapted to something. I could also imagine that I'd like to run the code for the actual movement decentralized on Arduinos. Y/w. I hope to expose every user-directable function as a pythonic API, suitable for scripting from, say, CyberPonk's Horsona library. Even Bash scripting isn't off the table ATP. >The realization and the command to do a set of movements, the motion planning, and the execution of the commands to the servo might be on different hardware (SBCs and controllers). Yes, very much so. Anon's IPCnet is the backbone to allow such distributed, decentralized computing to occur within our robowaifus. >>34167 >I might draw and scan something tomorrow Hope to see it soon, NoidoDev! Cheers. :^) >>34171 POTD This is growing into something important to us here, IMO. Keep it up, Anon!

Hear my schizo post, Anons. I think I have a good idea. We should use this train of connections to form an electric muscle. <Bone tether => Actuator Housing => Generic electric motor => magnetic sun-gear reduction => spool => tensile cable => bone tether. Don't forget a reset spring that . Turning on the motor puts torque through a double-acting gear-reducer, and clutch to wind up a spool, to pull a fiber, to pull the muscle tethers. Why this train? First off, you'll need to see this: https://www.youtube.com/watch?v=eaMD_9kOlTA&t=154s This video is the work of a genius on a magnetic gear train. Why do you care? Because... >We can swap out one of the magnetic gearwheels with *electromagnets*. >Electromagnets will vary strength based on the current running through them, and this allows us to essentially have a *frictionless clutch* between the electric motor, and the muscle fiber. A frictionless clutch! >The sun-gear set is concentric! We can fit them all into a tubular housing with a skinny aspect ratio! This takes a ton of complexity out of controlling the actuator. It will act like a muscle. You turn on the motor and activate the clutch, the muscle pulls. Turn up the power of the motor/clutch, it pulls harder. When you're done, it relaxes and resets to the spring settings. If the muscle is strained harder than it pulls, the clutch simply slips! It's cuddle-safe! This allows us to: >Spin up the motor and dump the clutch for explosive movement (can be dangerous). >Use the clutch slippage strength to vary or cap muscle tension for safety reasons. >Cap the power of the electric motor for safety reasons. >Simplify motion control to an easy pair of inputs that a neural network will easily understand. (clutch and motor) >Simplify the actuator to be easy to repair and replace. >Create a skinny actuator package which fits well onto a skeleton. >Quiet down motor whine because gear reduction. >Get sufficient torque because gear reduction. >Tune the neutral pose of the body by just pre-tensioning the springs (It would be nice if the roboGF could do this automatically somehow, would save her a lot of battery). >Have at MOST two pairs of wires per muscle. >Sink the actuator package into the bone itself if you so please (to save volume) >Use simple, off-the-shelf parts which you can get in highly variable sizes. Just build a good skeleton, and place a fucking ton of these things on it Have like 5-20 different sizes of e-muscles. Little skinny ones as thin as a pencil should be controlling the face. Big fat ones should be running the biceps. Excuse my drawings for being rough drafts, I just want you to get the picture.

>>34161 I meant that passive dynamic research has provided different mechanisms, algorithms, and equations which would benefit your designs in general. What works for walking, works for anything else that relies on dynamics. We all need to keep an open mind for using previous research in novel ways. For instance, you're working with breaks, and passive dynamic research involves using breaks to optimize energy use with gravity.

>>34319 POTD This is great stuff, Anon. I'd suggest you also have a look at the linear actuators for the Juggler Bot Anon's designs. They are fairly closely related to your approach as well, I think. I hope & pray you'll actually get the resources together to make these actuators real, and then share your experiences here with everyone. Please keep the great ideas coming, Anon! Cheers. :^)