/robowaifu/ - Actuators For Waifu Movement Part 3

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Actuators For Waifu Movement Part 3 Kiwi 12/06/2023 (Wed) 01:18:16 No.27021

(1stl thread >>406 2nd thread >>12810) Kiwi back again with a thread for discussing actuators to move your waifu! Part Three! Let's start with a quick introduction to common actuators! 1. DC motors, these use brushes to switch the ferrous core electromagnets on a rotor to rotate its magnetic field relative to surrounding magnets! They're one of the cheapest options with an average efficiency range of 30 to 90%. Larger DC motors and motors with higher turn counts are more efficient. 1.5 Coreless DC motors, by removing ferrous materials, losses from hysteresis are almost eliminated, dramatically increasing efficiency to nearly 90% even in small motors. Eliminating the ferrous materials reduces flux focusing, resulting in weaker fields and higher speeds. 2. Brushless DC motors (BLDC), these use a controller to switch the electromagnets on a stator to rotate the magnets of a rotor! Without brushes, they have the potential to be more efficient with higher power density compared to DC motors. Their efficiency and behavior vary depending on the algorithm and sensors used to control them. Coreless brushless motors exist but are rare and only used for very niche applications. 3. AC motors, a wide and incredibly varied category. They all rely on AC’s frequency to control them. With single phase AC motors relying on shaded poles, capacitors, or some other method to induce a rotating magnetic field. 3 phase AC motors naturally have a rotating field which usually gives them higher efficiency and power density. Notably, most AC motors are brushless. The most commonly used brushed AC motor is the universal motor, which is 4. Stepper motors, brushless motors with ferrous teeth to focus magnetic flux. This allows for incredible control (stepping) at the cost of greater mass, subsequently giving them higher rotary inertia. Usually 50 to 80% efficient depending on control algorithm/speed/and quality of the stepper. Due to their increasing mass production (& ubiquitous low cost controllers), they have appeal as a lower cost alternative to BLDC motors if one carefully designs around them. 5. Coiled Nylon Actuators! These things have an efficiency rating so low it's best to just say they aren't efficient. (0.01% typical, 2% achieved under extremely specific conditions in a lab.) Though they are exciting due to their incredible low cost of fabrication, they’re far too slow and the energy requirements are nonsensical. https://youtu.be/S4-3_DnKE9E https://youtu.be/wltLEzQnznM 6. Hydraulics! These rely on the distribution of pressure in a working liquid to move things like pistons. Though popular in large scale industry, their ability to be used in waifu's has yet to be proven. (Boston Dynamics Atlas runs on hydraulics but it's a power guzzler and heavy) Efficiency varies wildly depending on implementation. They would work great for a giantess! 7. Pneumatics, hydraulics lighter sister! This time the fluid is air! This has the advantage in weight. They aren't capable of the same power loads hydraulics are but, who wants their waifu to bench press a car? (Too loud and inefficient for mobile robotics.) 8. Wax motors, hydraulic systems where the working fluid is expanding melted (commonly paraffin) wax! Cheap, low power, and produce incredible forces! Too bad they're slow and hard to control. 9. Explosion! Yes, you can move things through explosions! Gas engines work through explosions! Artificial muscles can be made by exploding a hydrogen and oxygen mixture in a piston, then using hydrolysis to turn the water back into hydrogen and oxygen. None of this is efficient or practical but it's vital we keep our minds open! Though there are more actuators, most are derivatives or use these examples to work. Things like pulleys need an actuator to move them. Now, let's share, learn, and get our waifu moving! Servos! These use an actuator and sensor to control motion. DC, coreless DC, and BLDC motors are the most commonly used actuators for servos in mobile robotics. Potentiometers or hall effect sensors are the most commonly used sensors to detect rotary motion in servo systems. >Soft muscles (pneumatic system) with origami-inspired skeletons: https://youtu.be/OJO4FP0DXgQ[ >Printed pneumatics (TSA can also be used instead of pneumatics for actuation.) https://youtu.be/_X0rDW6NQ58 >Using sugar as soluble support material for printing silicone muscles: https://youtu.be/L0Z0-y3qpNk >Cavatappi artificial muscles (hydraulic coiled nylon hybrid): https://youtu.be/yXAJGH5s4cs https://youtu.be/MpCFumHFZvU https://www.designnews.com/automation/cavatappi-robot-muscles-have-5-times-strength-human-muscles >Twisted string actuators (TSA) Be extremely careful when choosing your strings. They will be put under extreme strain and must be durable. https://youtu.be/N4VMoYFrusg https://youtu.be/hFuzQ4ed-t0 https://youtu.be/J26y1nn7JMM https://youtu.be/zYrHGMiqC9A https://youtu.be/PABVsuV7Y1M https://youtu.be/tP9B3aqc4CI https://youtu.be/Y1uceDzhjKY >Continuous ransmission (CVT) / torque converters https://youtu.be/kVPjhmTThPo https://youtu.be/cd2-vsTzd9E https://youtu.be/c9e2y-5DMNc https://youtu.be/PEq5_b4LWNY >=== -edit subj

Edited last time by Chobitsu on 12/06/2023 (Wed) 03:06:55.

Grommet 03/11/2025 (Tue) 02:25:05 No.37425

I found something that I didn't know while looking at some of Robert Murray's stuff. This is one of those things you might want to keep the back of your mind as it may come in handy. I found that Silicon Carbide diodes have very high temperature ratings, they have almost no time to switch from on to off and are more efficient with less leakage. Silicon needs a finite amount of time that can cause problems. They appear to be close to indestructible compared to silicon. The reason this appeals to me is I'm interested in switch reactance actuators and all other sorts and you are going to have to have diodes to stop high reverse currents AND, while I do not know this for sure I expect that we can build our own. They are in a class called Schottky diodes and these were made a really long time ago with a semiconductor like silicon carbide and a metal. "if" you have 300 muscle circuits you are going to need a lot of them and you can buy silicon carbide super cheap by the pound for abrasives. Maybe you could use this stuff??? I'll look around and see. It beats trying to solder 600 or so diodes. These you might could silk screen them on. https://en.wikipedia.org/wiki/Schottky_diode https://www.electronicdesign.com/technologies/power/power-supply/discrete-power-semis/article/21193085/schottky-diodes-the-old-ones-are-good-the-new-ones-are-better I "think", not sure at all, that you can also make transistors from SiC...hmmm.... not sure. Something to think about.

Robowaifu Technician 03/11/2025 (Tue) 04:17:13 No.37433

>>37425 Any idea how well they handle high voltages?

Grommet 03/11/2025 (Tue) 08:26:33 No.37441

>>37433 >high voltages Yes noted for it's high voltage handling. They are using them in auto motors because of this. Far better than typical silicon. Not that I completely understand this but normal P-N type silicon diodes have a built up charge barrier when reversed. It takes energy and time to reverse this and allow current to flow. Schottky diodes do not have this and are therefore faster and if I remember correctly more efficient. Note there is Schottky diodes made of silicon. I'm mostly talking about the SiCarbide ones though to be specific but I of course do not rule out others that I may not have heard of yet. SiC has very high temperature ratings. I wonder. One of the metals used to make Schottky diodes is tungsten which of course has very high melting point. I wonder if you took some SiC powder and electroplated it with tungsten would that work????

Grommet 04/21/2025 (Mon) 00:35:46 No.37623

>>37425 > Schottky diodes...silicon carbide and a metal....you can buy silicon carbide super cheap by the pound for abrasives. Maybe you could use this stuff??? The Llama 3.3 70B AI is very skeptical of this approach. It doesn't say you categorically couldn't do it, but it seems to discourage the idea this can be done. I'm still not so sure that some sort of functionally useful Schottky diode can not be made economically. After all these were made in the early days. This is likely one of those things I'll have to keep n the back of my mind and slowly research and maybe something will pop up.

Chobitsu 04/21/2025 (Mon) 17:39:43 No.37627

>>37623 Interesting, Grommet. Do you have a good feel yet for why it's spitting that negative response back?

Grommet 04/24/2025 (Thu) 09:12:49 No.37754

I've been hunting for this paper. I found it when the site was down and thought it very good but when I went to find...arrrggh. It's about using black sand, basically iron oxide you dig up in a yard or find in a steam to make electrical parts, including motors and actuators. I told Chobitsu you could do this but didn't have a paper that backed it up like this one. The reason I couldn't find it was I forgot the name and the title didn't have iron or F2O3 or whatever. So searching all over didn't help. But I finally did. It's great and a way to cheaply get material to make your own motors and actuators using "dirt" as the permeable material. Like the electrical steel in motors and transformers. Here's the link and on that page is a download for, "Digging Dirt: on Inductors: Experiments with Custom Magnetics Made from "Black Sand."" https://hpfriedrichs.com/radioroom/inductors/inductors.htm One thing he found was that while iron oxide is not the best permeable material he found that as long as it was not over driven with too much magnetic field strength it had very low Magnetic reluctance which like resistance in circuits but for magnetics. So good efficiency at low field levels. This is fine for us because you can get fairly strong forces with even this material. This is well worth reading even if you don't plan to use iron oxide as a material.

Grommet 04/24/2025 (Thu) 09:15:54 No.37755

>>37627 >spitting that negative response back I think purity and maybe not crystalline enough. Basically rough material. I'm guessing so don't count on that as definitive. It could be wrong though. People made crystal radios in the old days from rough stuff. I've caught AI's saying wrong things more than once. But they are sooooo useful, mostly.

Chobitsu 04/24/2025 (Thu) 23:59:13 No.37764

>>37754 That's really pretty cool, Grommet. Stuff like this gives me hope that humans will be able to recover from catastrophe should the need arise. Cheers. >>37755 Yeah, that seems to make sense to me.

Grommet 04/25/2025 (Fri) 06:45:15 No.37780

>"Digging Dirt: on Inductors: Experiments with Custom Magnetics Made from "Black Sand."" I want to say one more thing about this article. If you look at the price of motors, actuators, etc. they are high as hell (for the numbers we need for real looking waifu's)and with the recent tariff troubles they are only going to get higher. I think that there is no way possible to economically make a robowaifu if you buy all these actuators. So the article above may not be exactly what you need but it's a great good start and shows you can do this with found materials and some methods. I've been looking at synthesizing iron oxide nano-particles. There's a LOT of work on this. Some of it doesn't look extraordinarily complicated though I just started looking. I don't know all the numbers yet but the reason its so popular as a research subject is these have great permeability and a very high level of magnetic flux before they choke. This paper looks REALLY GOOD for making these. A quick preview I see no super odd chemicals needed or specialized equipment. "A Milestone in the Chemical Synthesis of Fe3O4 Nanoparticles Unreported Bulklike Properties Lead to a Remarkable Magnetic Hyperthermia" bulklike It uses PEG which can be bought as a laxative Polyethylene Glycol Powder for Solution (MiraLAX) and Iron oleate I don't know for sure yet but oleate is a surfactant so I expect you make the above from it and iron I don't think this will be a huge problem. None the less if you can start with regular black sand from the ground or streams and then try more powerful stuff. I only started looking to make this stuff when I priced permeable powders and they were high. China had them reasonable but the shipping cost alone was like $90 for a couple kilos. Now, way higher.

Chobitsu 04/25/2025 (Fri) 16:25:46 No.37802

>>37780 >I think that there is no way possible to economically make a robowaifu if you buy all these actuators. Now you're getting it, Anon: actuators have always been the highest-cost single factor category of constructing pleasing & effective robowaifus (solely b/c the software coming from here is FREE [as in beer & speech: MIT-licensed (so, actually free speech! :D ]). This is one of the highly-important reasons why Kiwi, myself, and other cadres are so pleased with the ideas of Tensegrity : ( >>37672 ) for humanoid robotics. Amongst the many, many benefits this approach brings to us here on /robowaifu/ , significantly-reduced actuation costs (primarily due to significantly-reduced mass : >>4313 ) is a BIG one. <---> I like this guy's stuff, Grommet. Thanks for introducing us here to him! Cheers, Anon. :^)

Edited last time by Chobitsu on 04/25/2025 (Fri) 18:34:42.

Grommet 05/02/2025 (Fri) 07:22:01 No.38110

Artificial Muscles from Fishing Line and Sewing Thread haines2014 abstract https://www.science.org/doi/10.1126/science.1246906 paper https://sci-hub.ru/10.1126/science.1246906

Chobitsu 05/02/2025 (Fri) 12:32:33 No.38118

>>38110 Seems like we've been over this before, and it didn't seem to turn out positive. Didn't one of our guys actually do a fair bit of realworld experiments on this idea? Regardless, I'm sure the potential there is real. It's simply going to take a professionally-manufactured set of components to pull off well, AFAICT. The >tl;dr being this isn't well-suited to typical Anon's garage lab approaches.

Grommet 05/04/2025 (Sun) 02:01:28 No.38154

Crystal Structure and Magnetic Properties of Fe3O4 Nanoparticles Using Iron Sand as a Raw Material for Mercury Removal https://jonuns.com/index.php/journal/article/view/1240/1234 The key here is not mercury removal but making nano magnetite (Fe3O4) from black sand you can dig up. Nano magnetite (Fe3O4) has very high superparamagnetism. Means that magnetic fields are channeled through it at a very high rate and the material has high saturation figures to these fields and it makes for very high power solenoids or electromagnets. An it's totally non toxic to boot. They use this for contrast in medical scans. People swallow it. Here's a paper that goes over, roughly, the main methods of making this stuff. Magnetite nanoparticles Synthesis methods – A comparative review IJCRT22A6681 https://ijcrt.org/papers/IJCRT22A6681.pdf It's a good brief review and if you are at all interested in making magnetic actuators, from scratch, you should download it. That and the paper using black sands directly above. It also has the references in it to learn the methods. There are many. A paper needed is a way to make a flexible rubbery like conductive material. Combine these and I think you would really have something.

Grommet 05/04/2025 (Sun) 07:53:00 No.38166

I found a really, really good video on this, Making ferrofluid from scratch https://www.youtube.com/watch?v=6L8yUY-doNc

Chobitsu 05/04/2025 (Sun) 20:14:10 No.38186

>>38166 Great information, Grommet! Thanks & cheers. :^)

Robowaifu Technician 05/04/2025 (Sun) 20:20:12 No.38187

>>37780 What application are you trying to synthesize them for? Are there any requirements for size or crystal structure of the nano particles? If so what are the tolerances?

Grommet 05/05/2025 (Mon) 08:25:12 No.38224

>>38187 >What application are you trying to synthesize them for? Magnetic amplifiers, solenoids and electric motors Are there any requirements for size or crystal structure of the nano particles? If so what are the tolerances? They are typically looking at 5-20nm. For our purposes I suppose we could do with larger. A lot of research is for medical use. The magnetic particles provide high contrast for medical imaging equipment. Me, I want to tag along on their research. I will not say that I can write a symposium on all the effects of this but I get generally that they have very high permeability, they are able to sustain high magnetic fields without them choking and becoming a high resistance. As a general rule higher permeability means higher frequency and much smaller equipment with larger forces. Concentration and force per magnet field force is the big one. They also have a benefit that they can operate as one large mass, though I'm not exactly sure about all of the relevance of that but I believe it's directly related to the other traits I just listed and, I think it lowers eddy currents which are wasted energy. If you are making magnetic amplifiers from them you can use a much smaller (very small)DC voltage to control a very large AC voltage and current. This could come in very handy. They used these to control theater lights and battleships turrets in WWII. They are VERY robust. There's, I think, two different forms they're looking for. One is better than the other but I think both "not bad". I believe the one with less oxygen F3O2, a guess, is better, but I could be wrong. I have briefly looked at the papers but I can't remember all of the details off hand. The data is in the papers and in the video that I linked. The two forms have different crystal forms.

Grommet 05/05/2025 (Mon) 08:40:20 No.38225

I may have it wrong. I think this is the form you want 2 Fe3+ + Fe2+ + 8 OH− → Fe3O4↓ + 4 H2O So more oxygen??? I note that the synthesis in the video he worried about too much oxygen as he was stirring upsetting the reaction to a less desirable state. I think it might produce side reactions that are none of the above. FeO maybe??? I;m not a chemist but took a couple chemistry courses so I know just enough to know, that I know very little. Like Barbie says,"Chemistry is hard". Here's links on these, https://en.wikipedia.org/wiki/Iron_oxide https://en.wikipedia.org/wiki/Iron_oxide_nanoparticle

Grommet 05/05/2025 (Mon) 08:47:03 No.38226

If I could easily get powders online I wouldn't waste my time with this but the people supplying this are typically only interested in selling you tons and you have to sign up, talk to reps, it's a huge annoyance and on their part they don't care. They want to sell the already made cores not the powders. The ones who list just powders, with price, want an ASTRONOMICAL fee for them. It may very well end up that using black sands or some chemically made version of them is the best path even if the material is inferior. I wish I could get a couple kilos of Sendust alloy powder. That would be good. China will sell it to you but the shipping is a killer and now, with tariffs and trade disputes...not going to waste time on that.

Robowaifu Technician 05/05/2025 (Mon) 13:38:09 No.38232

>>38224 Nile red's video looks like your best bet for making them at home. If you are really interested in the biomedical applications you could try cultivating magnetotactic bacteria for their magnetosomes. You would have more control over chemical composition, size, and shape, but it is a slow and energy intense process and it is not a mature process. If you are making them on a small scale those might not be huge issues. https://microbialcellfactories.biomedcentral.com/articles/10.1186/s12934-020-01455-5

Grommet 05/05/2025 (Mon) 18:59:05 No.38242

>>38232 >interested in the biomedical applications I have zero interest in biomed. Only noted it as this is the a lot of why they are researching this.

Grommet 05/07/2025 (Wed) 00:44:18 No.38277

I found these brief articles. It's a great summary of why to use permeable materials for actuators, motors, etc. Very concise and short with a lot of info using graphs. https://www.horizontechnology.biz/blog/what-is-sintered-soft-magnetic-material https://www.horizontechnology.biz/blog/iron-powder-types-permeability Earlier I noted that one of the advantages of nano-materials is that they acted like one solid mass. I didn't really understand thta til I saw this i the article, "...However, what if your design requires higher perm and saturation? A logical transition is to the iron phosphorus material now with the benefit of advanced compaction technologies. The higher densities - up to 7.3 g/cm³ will promote higher perm - up to 4000 coupled with higher saturation induction..." So "maybe" the nano materials act like a compressed solid without actually sintering it into a solid, or so I read it that way. Maybe I seem to be blathering away a lot about this but in my opinion it;s at the very root of making efficient actuators. Now if a way can be found to make coils using these powdered materials without actually winding them up... Lots of resources here, https://www.horizontechnology.biz/soft-magnetic-composite-resources?hsCtaTracking=bf1123d2-dd65-4967-a84e-b0297046fa01%7C22279883-1ca0-4188-85a0-15819ac3a283

Grommet 05/07/2025 (Wed) 01:07:01 No.38279

One more I find myself looking at. It's a coil gun link. Directly applies because it;s all about getting the most force from magnetic systems. https://coilgun.info/theorymath/saturation.htm

Chobitsu 05/07/2025 (Wed) 15:54:24 No.38294

>>38277 >Maybe I seem to be blathering away a lot about this but in my opinion it;s at the very root of making efficient actuators. Nah, it's fine Anon. We all get it, I think. I'm hopeful that @Axial will return soon to pick up his thread again (cf. >>36271 ). Your investigations into these things may have bearing there. >Now if a way can be found to make coils using these powdered materials without actually winding them up... This. Cheers, Grommet. :^)

Grommet 05/09/2025 (Fri) 03:13:42 No.38312

>>38294 >Axial I personally believe that any non return path, no permeable material, motor/actuator will always be inferior to the one with a return path. My understanding is it's like an electrical circuit and the permeable material is like a less resistive wire and a return path that has none, only air, is like a big ass resistor in a circuit. You will have way less magnetic force. If it;s such a good idea then why does every single electric car makers motors have permeable material to concentrate the magnetic field? Now it "may" be possible to use rare earth magnets and use purely attraction to the coils but REM cost a damn fortune and kill the price/performance level. Interesting factoid https://www.nextbigfuture.com/2025/05/nvidia-james-fan-proposes-physical-turing-test.html "1.5 million parameters is all that is needed to capture the sophistication of the human body for humanoid robot training." Anyone here know what that means exactly? A guess, 1.5 million bytes of data to monitor??? Or could it be nodes in an AI and if so what sort of compute would be needed for this. Anyone with a rough guess? Not a perfect guess but maybe one order of magnitude. I'll throw some numbers out there for fun. (not to be used for insurance claims nor do I accept responsibility for inaccuracies) A ESP32 microcontroller has 600 DMIPS. So at 1.5 millon parameters we have 400 operations per parameter and that's just a regular microcontroller. Looks as if one microcontroller could handle the whole entire waifu. Note that the whole body is not going to be moving so it could be less compute. Hell lets be generous and make one for gross body movement and one each for legs, head. You're still easily in range.

Chobitsu 05/09/2025 (Fri) 07:49:18 No.38314

>>38312 >I personally believe that any non return path, no permeable material, motor/actuator will always be inferior to the one with a return path. I don't have sufficient training in EM/Field-theory (yet) to know any better one way or other, but the instincts of my mind's imagination tell me that this is the correct take. >why does every single electric car makers motors have permeable material to concentrate the magnetic field? We have a video linked here on the board somewhere about the remarkable stator, etc., design of the newer Tesla motors. It would be nice to know more about the manufacturing techniques used to produce them! There's also another video about the 'print-in-place' method used behind an even more-sophisticated, smol'r design motor (in response to your 'make coils:no winding' comment posted above). <---> >"1.5 million parameters is all that is needed to capture the sophistication of the human body for humanoid robot training." <sauce: bull's a*rse With all due respect to those esteemed researchers, I believe this is yet to be determined! :D We simply can't say something like this definitively yet, I deem. But what we can say definitively is that the eminent Carver Mead has done extensive research on so-called Neuromorphics (being the founder of the field back in the day) [1]. And what Dr. Mead, et al, says is that the "intelligence" of creatures gets 'pushed out' to the periphery of their body plans. In other words, for us humans, a very large part (by far the majority) of our own sensorimotor / kinesthetic "understanding" happens not inside our brains -- but within our peripheral, spinal-column + limbs neural tissue! Certainly such a model of reality seems to me (at least with merely a surface, cursory view on these matters; as yet) to warrant against using just a simple, "LLM-focused" discourse as the correct method to approach understanding these robotics C4 systems [2] topics with. /$0.02 . <---> As to your back-of-the-napkin estimate of the h/w power needed for our robowaifus to be safe & successful, effective & pleasing waifus... again, hard to say yet. OTOH, I'm rather-confident that we can, in fact, solve the basic kinematic needs part with a reasonably modest array of smol SBCs & MCUs + sensors, etc. [3] Its the very language/emotions & world-modelling/judgment problems themselves that may need an inordinate amount of compute to manage well, I think. Stay tuned. My understanding is that most of us plan to use some sort of home server setup for offloading robowaifu compute. Personally, I mean rather to have it all onboard in the nominal case; I'll be satisfied (at least at first) with having conversations not much more extensive than her saying "Chii?", "Chii!", "Hideki?", "Hideki!!" After all, teaching her about life & things is where all the fun is! :DD Cheers, Grommet. :^) --- 1. (cf. >>12828, >>12857, >>12861 ) 2. Command, Control, Communications, & Compute. While our needs here as robowaifuists go much-deeper still **, these are the commonplace basics we'll need to solve just to 'get off the starting block' with advanced, realworld robowaifus. ** (cf. >>10000, >>24783, >>17125, et al) 3. With the fundamental proviso that the software itself running on said hardware is highly-efficient, realtime-compatible, C++ & C code!

Edited last time by Chobitsu on 05/09/2025 (Fri) 18:19:43.

Kiwi 05/09/2025 (Fri) 22:19:34 No.38322

>>38312 >>38314 >Motors without permeable material to control flux paths They're fine, there's trade offs. Motors without flux guiding material (called coreless) can respond to changes in electromagnetic fields faster. This is useful in certain fields, such as RC cars and animatronics where high reaction speeds are crucial and budgets are small. They have far lower torque without flux focusing. Usually, this is overcome via having a larger armature diameter and/or gears. Efficiency isn't a problem, the flux from the coils is still used to push against the flux of magnets effectively. They can still have 98% efficiency if designed correctly. It's best to just think of it as, coreless has higher speeds and reactions, flux focusing motors have higher torque, relative to each other. They're both equally useful, just for different purposes. This train demonstrates it well. https://www.youtube.com/watch?v=G2r_Ucd2Fdw >Why do electric vehicles use permeable materials to control flux paths? Min-maxing torque per cost and mass. The physics governing them is different from what we are dealing with. (Unless you're building a waifu that's gigantic and needs to move tons of mass affordably.) Many cars such as modern Tesla's, use SynRM motors. They're a half step using flux paths so they can get away with smaller, cheaper, lighter magnets. It's all about being cheap while having enough torque to throw tons up a hill. For us, brushless is far superior and is cheap due to mass production. >How are they made Dies pressing metal sheets into shapes. High silicone steel pressed into many layers to direct flux fields. Shove wound coils and magnets where needed. Spice it up as you want depending on the car. https://www.youtube.com/watch?v=oVge8I6kxPY https://www.youtube.com/watch?v=-Uw0v6YaIc0

Chobitsu 05/09/2025 (Fri) 23:12:22 No.38323

>>38322 >It's best to just think of it as, coreless has higher speeds and reactions, flux focusing motors have higher torque, relative to each other. Thanks! Makes sense. Sounds like -- as with all engineering -- its a matter of tradeoffs, and choosing the best in-situ approach.

Grommet 05/10/2025 (Sat) 01:38:21 No.38328

>>38322 >Motors without flux guiding material (called coreless) can respond to changes in electromagnetic fields faster I do not believe that to be true at all. Some of the very fastest reacting motors are switched reluctance motors and all the rotor is "is" a permeable material.. .That's all it has in it. "...SR technology promises an impressive set of benefits over its competition. Among these are high efficiency over a wide speed range (and partial loads), high-speed capability (>100 krpm, with the proper drive), easy cooling with heat source only in the stator, ruggedness for high-temperature or vibration environments, and relatively simple mechanical construction (see “SR motor anatomy” online). ..." "...SR systems deliver high efficiency across the entire load range..." "...Cool-running SR motors also allow temporary high-current operation for peak torque output for severe applications..." I don't have the link offhand, it's somewhere, but I've also seen that SR motors can accelerate and stop super, super fast. Like 50,000 RPM and stop in milliseconds. . https://www.controleng.com/articles/resurgence-for-sr-motors-drives Here's a link I linked here, >12014 Tesla motor. Sandy Monroe associates who tear down and cost cars. He has a great electric car company comparison on their motors and drive electronics. The link again direct, https://insideevs.com/features/443775/tesla-motors-invertors-compared-competition-sandy-munro/ I've seen these taken apart. The picture kiwi put here, >38322 shows the general layout from the side. These are a bunch of thin iron, likely, high silicon plates, that are electrically separated by some sort of paint. Without separation they induce currents in each plate and heat up. The thin plates guide the magnetic fields. The spaces are stamped out holes. In some cases they have rare earth magnets in them or near by. A little speculation here. I know what the spaces are for. Since air has terrible permeability the spaces "guide" the magnetic fields to go around the spaces. I believe the reason they do this is the longer path is much like a lever arm. If it were too short less of the material would be attracted but the slots make sure it goes through a larger portion. Tesla has magnets in them too towards the center. More speculation. I say that the magnet also operate like the slots but serve dual purpose. It's a fact that DC magnetic fields, like in magnetic amplifiers, block magnetic flux. So I'm guessing the magnets extend the field like slots but also switched reluctance motors have a bit of cogging or jerkiness to them. I suspect the magnets help smooth this out so they can have less complicated electronics. The jerkiness or cogging can be eliminated by electronics but it gets tricky. I think the picture above is wrong. I see fields going through the slots... that doesn't look right. Maybe the area with slots have magnets in them and they are showing the magnetic fields lining up with the magnets??? If so they should have used different colors for those fields attracting the magnets and those going through the steel plates. It would have been more clear.

Grommet 05/10/2025 (Sat) 01:50:11 No.38329

>>38314 >>"1.5 million parameters is all that is needed to capture the sophistication of the human body for humanoid robot training." <sauce: bull's a*rse With all due respect, I think this is yet to be determined! :^) Maybe I should have made it clear that "I" personally am not declaring this to be so. Only that I saw this link and the people proclaiming that are not necessarily idiots. Note I did ask just what these "parameters" might be. What "I" said might be needed I covered here, >22109 I came up with 240 joints and three muscles for each joint so I guess you could call it 720 parameters. Not covering the face so call it a rough 800 for a total.

Grommet 05/10/2025 (Sat) 02:43:42 No.38330

I found this really good chart and it shows the type of electrical motors and the range of action based on "interaction torque", which I suppose is the coreless and straight magnet types, and the "inductive reluctance" torque with supposing the Switched reluctance all the way towards the reluctance side. https://assets.rebelmouse.io/eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJleHBpcmVzX2F0IjoxNzQ2OTEyMjYyLCJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy81MjUxMzg2Mi9vcmlnaW4ucG5nIn0.LiOyiRB1nxkTyB16vypaiM6TVXHBq-SkXYAu5Cz8uwY/img.png

Chobitsu 05/10/2025 (Sat) 02:44:34 No.38331

>>38329 No worries mate, I knew that. <---> >Note I did ask just what these "parameters" might be. Which kind of feeds into my main point: treating the manifold physical aspects of a full-featured, natural-motion robowaifu as 'language model tokens' is fundamentally the wrong discussion to have, IMO. >I came up with 240 joints and three muscles for each joint so I guess you could call it 720 parameters. Not covering the face so call it a rough 800 for a total. All the interrelated finite-element-analysis + dynamical, floating center-mass, inertial-moment imparts of all these multi-nodal lever complexes (alone & in coordinated groups) would also need to be accounted for, to have asymptotically-complete descriptions of all the mechanics involved. >tl;dr In the millions at least, actually. <---> Thankfully, we don't have to have perfect simulations in advance. In the realworld, we can simply test + record results => adjust => lather, rinse, repeat. >ttl;dr HUMAN INSTINCT will take us 90% of the way there; science & good engineering will run final leg across the finish line. If it was good enough for my Grandpappy, it's good enough for me!! :DD

Edited last time by Chobitsu on 05/10/2025 (Sat) 03:09:44.

Grommet 05/10/2025 (Sat) 05:55:45 No.38333

>>38331 >treating the manifold aspects of a full-featured, natural-motion robowaifu as 'language model tokens' is fundamentally the wrong discussion to have Yes, I agree. I had a thought. I took statics in college. It's mostly about adding all the forces up all over a structure and translating them to a fixed point or some cases a dynamic moving point. I see no reason the same can not be done. So each and every muscle/joint if rotated all about with varying force, in all directions, then stopping, recording the acceleration, deceleration and position. You get a force and a vector. Basically a calibrated value for how much it takes to move and to stop, with which momentum can be calculated. When moving, all these can be added up and if done correctly you can get the absolute mass force vector for any spot on the waifu. So as it's moving it can take, what's the last force vector(every joint, muscle, everything), add in the new force vector for all the parts(what you need to get to the next point) and you get the balance and position and you can calculate where and how much force to go where you need to be or if you are getting out of whack and need to correct before you fall over or hit something or etc. Now if you take my 240 joints and you have already run calibration on the waifu. You come up with something like a measurement of Kg-m/watt or how many watts to move the waifu where you want to go and where you have been so momentum is take account of. Each of these 240 joints would have a force and a X-Y-Z vector to show which way it was going(this would be a force-velocity vector in 3D). So 240*3=720 parameters + the same for the last reading to get your already moving speed-vector-force. This could also be calibrated by vision and force if it's walking when it hits the ground to see that the various inaccuracies will not add up to being completely discombobulated. While there's more to it than that it's not far off from actually describing what, I think, needs done. With such a small number of values and the blistering speed of today's microcontrollers I think you could check and correct these at a very high rate. So 600 DMIPS/(720 now + 720 last)=416,666 instructions for each second of movement. So every miliSec you could do 416 computations per joint including velocity vectors. That's a lot. I thnk you could set these force vector numbers up in such a way that you could just add them. I can;t remeber how we did it in statics but it seems like we did much the same, but with beams, buildings, etc. and just added up the forces and the X-Y-Z vectors. Maybe we took the sin of the force then added? Can't remember. I wonder how many instructions adding a vector would take.

Robowaifu Technician 05/10/2025 (Sat) 06:13:08 No.38334

>>38333 >I wonder how many instructions adding a vector would take. Once the data is moved into the registers, one.

Kiwi 05/10/2025 (Sat) 07:14:44 No.38336

>>38328 >Doubting coreless response to flux changes are faster than switched reluctance motors. I understand why you'd think that given your example. Coreless motors rely on torque interactions between permanent magnets and electromagnets. Reluctance motors rely on torque from reluctance, inducing magnetic fields into the rotor that then react to electromagnets. The material naturally has some reluctance, which is beneficial for controlling rotor position, but also reduces the speed at which the rotor can react to changes in the stators flux. It's a difference in speed that is small but, it exists due to the inherent physics of the respective systems. As for why race cars don't use coreless motors, the difference in costs between a coreless motors magnets and a switched reluctance motors electrical steel sheet rotor are enormous. The difference in performance at that scale using modern control algorithms is small. It's a simple cost benefit analysis lead decision. A coreless motor race car would perform just as well, but it would cost tens of thousands of dollars more, for barely any difference. >50,000 RPM and stop in milliseconds. These numbers aren't impressive for electric motors. That RPM is easily achieved by bog standard motors of all kinds. Almost all motors can also stop within milliseconds in a system designed for it. I understand how these numbers can seem impressive, they seem large compared to what we interact with normally. >Motor plates Those are made of electrical steel, a type of steel you correctly guessed is high in silicon. They have a strong dielectric separator. Which, could be a type of paint, resin, or other material. Paper can be used to separate them, I've seen it in big old motors used as pumps. >Speculation on flux guides They're actually really simple, they're there to keep the flux going straight from stator pole to stator pole. Consider a disc, without slots, the flux would permeate it evenly. This would prevent the rotor from having external torques rotate it. With slots, the disc now acts like it has many independent poles for the flux to travel through, providing a way for the torques to rotate. Consider picrel, because of the flux paths, both motors have the poles. The discs poles are physically larger, allowing for more flux and thus, more torque. The space between the poles is also smaller, reducing torque ripple and allowing for smoother operation. >Tesla The magnets in the slots are just there to provide magnetic flux like any permanent magnet motor. They're just small to save on costs utilize the designs of switches reluctance motors to get more power than the magnets would allow on their own. It's a really clever way to save heaps, because magnets at that scale are expensive. It's a cost saving half step between a switched reluctance motor and a permanent magnet motor. You are correct in that this kind of motors inherently has less cogging than a standard reluctance motor. The major problem for us is the lack of mass produced reluctance motors at the scale a waifu would use. They would cost less but, be larger and heavier to achieve the same power output as standard brushless motors. Which is why those brushless motors are common instead, the added cost is worth the higher power density at smaller scales. At large scales, the costs of materials adds up, making reluctance motors attractive. A larger motor and a few extra pounds, are worth saving tens or hundreds of thousands of dollars in manufacturing.

Chobitsu 05/10/2025 (Sat) 07:39:00 No.38337

Magnetic shock-absorbers? Kind of 'anti-actuators' AFAICT. May be just the ticket for smooth robowaifus gaits & movements. https://www.tiktok.com/@super.accelerator/video/7487984992623004950

Chobitsu 05/10/2025 (Sat) 07:41:00 No.38338

>>38336 POTD >At large scales, the costs of materials adds up, making reluctance motors attractive. You encourage us all, fren Kiwi. Cheers. :^)

Grommet 05/11/2025 (Sun) 04:54:18 No.38367

>>38336 >The material naturally has some reluctance, which is beneficial for controlling rotor position, but also reduces the speed at which the rotor can react to changes in the stators flux Ok I do get that. Makes sense. >difference in costs between a coreless motors magnets and a switched reluctance motors electrical steel sheet rotor are enormous ehhhh...I don't buy that. Yes this used to be true. Every time you see any article on pure reluctance motors they always bleet on about the control system but you can get microprocessors for 50 cents now or ones with more outputs that are less per drive and the transistors to drive them cost much the same for either. I'm not saying it's not more difficult to set up but once you do, I think the cost is way less. If I'm not mistaken most appliances the major motors have all moved to some form of reluctance drive because...cost. I think there's just way fewer people that can easily design reluctance drives. I never said it was easy, so therefore, there are less of them. Most car manufacturers are,likely, moving towards reluctance drives with some, a magnet here and there. >50,000 RPM and stop in milliseconds. I am impressed by this. Most of the electric motors I have dealt with were larger and couldn't dream of doing that on their best day. >a type of steel you correctly guessed is high in silicon Not a guess. Some are made of different alloys but the cheapest and most common is high silicon iron. I "think" there may be a way to use the high inductance in the Stator. The idea is to have not coils but sheets of aluminium. By using pulses of electricity into them combined with high inductance (the sheets are mixed up with the iron sheets/powders) you could have a lost cost system easy to put together. Winding coils is time consuming, costly and tedious. If you notice I went on and on about Don Lancasters "magic sine waves". Basically pulses adding up in a circuit to give you sinusoidal waves.Or maybe I didn't. I thought I did but I did provide a link. >>27823

Grommet 05/11/2025 (Sun) 04:58:20 No.38368

>>38336 >coreless motors magnets and a switched reluctance motors electrical steel sheet rotor are enormous I read that wrong you are correct.

Kiwi 05/14/2025 (Wed) 17:49:39 No.38485

>>38367 Good demonstration on how to build your own switched reluctance motor. https://www.youtube.com/watch?v=UFf304FkbiQ

Chobitsu 05/14/2025 (Wed) 21:01:30 No.38501

>>38485 Neat! I learned a lot just watching this about SRM. In a factory setting, we'd likely have our own laser cutters & jigs for assembly, etc. So, eventually we'd pretty much get down to just the marginal costs involved. I'm no expert here, but these seem to me to be fundamentally cheaper than more-typical electric motors of a similar capacity? <---> This guy seems pretty clever! Though he does need to learn a few things about his personal health & safety. And lighting for better f-stops! :D Nice find, Kiwi. Cheers. :^)

Kiwi 05/14/2025 (Wed) 22:35:33 No.38504

>>38501 It'd be trivial to mass produce 'em with a hydraulic die press, and a few jigs with simple sensors and steppers. Though, it'd take heaps of time and money, while requiring a shop for us to work out of. Even then, we'd need to make millions before breaking even relative to just buying BLDC motors and their respective systems. I still think it's worth keepin' in the back of our minds for when we have the capitol to make thse kinds of moves. Someday, I want to run a factory filled with waifu and anons buildin' waifu.

Robowaifu Technician 05/14/2025 (Wed) 22:38:02 No.38505

In terms of keeping cost down, what are some powerful motors that could be salvaged from a junkyard but also useful for building a robowaifu? I hear windshield wiper motors are pretty good and you can get them for next to nothing at junkyard yard.

Kiwi 05/15/2025 (Thu) 01:08:31 No.38507

>>38505 >Windshield wiper motors They have some complications but, are a fantastically high torque motor, relative to cost, https://www.youtube.com/watch?v=D7hkFh4uhMo&t=69s https://www.youtube.com/watch?v=3pYWLF8qw-g

Chobitsu 05/15/2025 (Thu) 04:04:24 No.38508

>>38504 POTD >Even then, we'd need to make millions before breaking even relative to just buying BLDC motors and their respective systems. Hmm. Makes sense. OTOH, your """favorite""" Afrikaner says they plan to roll out billions of Optimus's. So yeah, if we here hit it out of the park on behalf of the little guys, then I don't think millions is out of reach. It's certainly my dream already! :^) <---> >Someday, I want to run a factory filled with waifu and anons buildin' waifu. I LIKE THE WAY YOU'RE THINKING, ANON! This has been my dream for years now. Ultimately, I want to help Anons all over the world. But until that blessed day comes fully to fruition, I want to help the Anons of /robowaifu/ first & foremost. I'm trying to understand how to organize (smol, to start out with): * Obtaining basic-bey*tch funding (the 'find out fee' tier of cash) for the startup * Robowaifu construction facilities * Housing for staff (room & board) (temp. or perm., depends) * Transportation for relocation (temp. or perm., depends) * Unraveling the tangle of legal, &tc., bureaucratic red tape... Keep.Moving.Forward. Cheers, Anon. :^)

Chobitsu 05/15/2025 (Thu) 04:11:26 No.38509

>>38504 >That Sukabu tho... Normally, I don't care for such depictions of robowaifu gore; its personally offputting to me. But he is so skilled, and his depictions so tasteful, that I actually find them to be charming instead! :D <---> I sure hope he'll begin doing highly-technical breakdowns of his joints concepts (exploded-views, parts-breakdowns, range-of-motions, etc., etc.) The man has amazing talents as a concept artist! * Thanks & cheers, Anon. :^) --- * I hope we can actually hire him someday to visualize our robowaifu lines for ad-copy/propaganda/technical-manuals/&tc ! :D

Edited last time by Chobitsu on 05/15/2025 (Thu) 04:24:39.

Grommet 05/31/2025 (Sat) 08:42:50 No.38868

Interesting paper. Dielectric elastomer transducers with enhanced force output and work density https://sci-hub.ru/10.1063/1.4730953 The glitch on DE is the need for high voltage and low force per weight. I saw another paper where they talked about 0.73N-M/Kg. That sucks. Like 0.5 foot pounds of force per Kg. The paper above describes DE's that use less voltage and high permeability nano-powders to increase force. I have some troubles with the paper as the units are not clear to me what they mean. They say 705 mN blocking force...so per what volume or weight??? They also use the unit V/uM which I don't understand. Is this the volts per thickness??? This system of units volts per area has never been clear to me. 705 mN is still not a lot of force. as above 0.5 ft-pounds or so. I wonder that there could not be some way to combine this with hydraulics using the DE materials as switches. A major problem, or I think it is, is that all these coils for electromagnetic actuators are hard to wind and take expensive copper wire. If you could use DE at lower voltages and combine with some other actuation force it could cut cost and complexity of manufacture. There's another good paper on DE's that's a sort of survey, "Multi-functional dielectric elastomer artificial muscles for soft and smart machines " https://sci-hub.ru/10.1063/1.4740023 These DE's sound soooo good but when you look in to them the drawbacks really add up.

Chobitsu 05/31/2025 (Sat) 18:27:52 No.38874

>>38868 Ehh, don't be too discouraged about it, Grommet. IMHO, it's simply a matter of the misdirecting of goals. If one is trying to run main-force actuators (shoulders/hips, elbows/knees) with this then sure...probably quite insufficient to the tasks. OTOH, using these for something like facial animation, or perhaps even finger actuation, or pleasing volume deformations (as in muscle flexures, etc.) then these might be just the ticket today! <---> Regardless, I'm glad research is moving forward for this tech. Who knows but that they may make some breakthrough with it soon-ish? Cheers, Anon. :^)

Grommet 06/14/2025 (Sat) 01:42:45 No.39236

What appears to be a good paper. Good review of soft magnetic materials. You would want to know this as it pertains to any sort of electric actuator or motor. On the link http://zhao.mit.edu/all-papers/ you find the paper Yoonho Kim*, Xuanhe Zhao*, Magnetic Soft Materials and Robots, Chemical Reviews 122 which can be downloaded from there. He has lots of papers on robotics.

Chobitsu 06/14/2025 (Sat) 01:43:12 No.39237

>>39224 Thanks, Grommet! Nice resource. Cheers. :^)

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