/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 03/16/2024 (Sat) 11:23:04 No.30349

>>30309 I wish to bring to your attention two of his videos that seem to me to be the best. He has thousands and I've seen most. Here's simple ways to make graphene. One is a method to make graphene foam. title to search for "Making Graphene Foam From Table Sugar" The next is how to add whey. This keeps the graphene from recombining. I'm not sure if you need this. Maybe you could grind up from the first method and that would be good enough. There does seem to be a problem with dispersion into powders. With the liquid method you have a liquid. He was using it to reinforce concrete and getting really strong concrete. "If" you wanted to mix with a powder the whey treated graphene you would need to dry it. He says centrifuge. None of this is beyond kitchen chemistry. The strength of this stuff is off the charts. it makes steel look weak and likely anything you can get to mix it in will become super strong. "1933 Blood Graphene - A Way To Make Graphene From Blood, Eggs Or Milk"

Robowaifu Technician 03/16/2024 (Sat) 16:08:54 No.30353

Has there been any robots that used a shape memory polymer as an actuator? I know nitinol has been used for tiny bots. SMPs seems to rebound a fair amount faster than nitinol from what i can see in videos. You can actually even buy SMP filaments for 3D printing. Though problem I see is even if you use a mechanism to heat it locally and controlled the state such filament regains it's original shape is increased heat which also is what is required to reshape it so it's difficult to tell how much push or pull force it can provide.

Kiwi 03/27/2024 (Wed) 18:39:43 No.30547

Switched reluctance motors are great for gaining a better understanding of the physics which governs motor movement. https://www.youtube.com/watch?v=1IUVjp03On8 https://www.youtube.com/watch?v=TAhF45AtsgA

Kiwi 03/27/2024 (Wed) 18:46:10 No.30549

>>30353 Yes, they're about 1~5% efficient, are slow, need high precision heat control, do not work in cold or hot environments without good engineering, etc... Though cheap and easy as crisps, they just have too many problems. I like them and wish they can be cheap and electroactive while requiring sub kV range voltages If you're interested, read papers published on them and try to make your own. There's plenty of room for improvements and I'd be grateful to have a viable alternative to heavy gear motors. PLA and plastic polymers based on it could be a great and cheap start to your research. https://www.youtube.com/watch?v=SiOn-LqW4KI

NoidoDev ##pTGTWW 03/27/2024 (Wed) 21:15:18 No.30557

>>30353 I don't know why I overlooked that, but some of us want to use water cooling inside, then store it and it might be used for muscles (e.g. nylon) which are just complementary. I also think small muscles might make sense in some places, e.g. the face. > SMP filaments Thanks, I'll look into it. >>30549 Interesting, especially with that video, thanks.

Robowaifu Technician 03/28/2024 (Thu) 14:33:02 No.30578

>>30549 Isn't that 1-5% just for one specific kind the kind of coiled nylon muscles or I may be getting mixed up. Though I came across info on why heat is a poor activator, it is faster to heat an object than cool it so it isnt exactly even how it operates. Doing more digging I just now came across solid state actuators which includes things such as ionic polymer metal composites which seemingly can operate at low voltage. Ive yet to figure out performance and possible use of them. Im not sure why they think only make a flat object instead of a design that can have pulling force like a cross pattern or something XXXXXXXXX but maybe it would be too weak to be of use? https://www.sciencedirect.com/science/article/abs/pii/S1385894723027079 https://www.youtube.com/watch?v=E1jkAQ-pBpU >>30557 Id question using water. My thought was using electric heating wires to control the SMPs but Im second guessing using SMPs that require temperature changes.

NoidoDev ##pTGTWW 03/28/2024 (Thu) 18:01:52 No.30586

>>30578 >Id question using water. My thought was using electric heating wires to control the SMPs We had this several times during the years, not sure if something changed. If you have wires bending then they might break. I recall some video testing these actuators and the results simply weren't good. Good look anyways, but always keep in mind it has to work 10k*X times or 100k*X times.

NoidoDev ##pTGTWW 03/28/2024 (Thu) 23:59:11 No.30599

>>30353 You are probably the same who posted it, I'm just linking it here: Silicone shape memory polymer >>30584 - Idk, maybe this will be interesting for smaller muscles, like in the face.

Chobitsu 04/03/2024 (Wed) 19:00:22 No.30768

> Homebuilt Electric Motors Just leaving this here for now. https://www.bavaria-direct.co.za/

NoidoDev ##pTGTWW 04/18/2024 (Thu) 17:46:31 No.30955

>Servo Horn: Pick the right one. via >>30927

Robowaifu Technician 04/19/2024 (Fri) 00:09:29 No.30967

>>27021 >Boston Dynamics Atlas runs on hydraulics but it's a power guzzler and heavy Their hydraulic Atlas was retired and they have an electric one now. https://www.youtube.com/watch?v=29ECwExc-_M

aydoll 04/19/2024 (Fri) 19:09:30 No.30969

Well, the idea of using a rotary cylinder fueled by air or oil seems outdated now. Thank you Boston Dynamics, for saving me time and money, I guess :p Looking at how their servos look, the idea would be to DIY our own servomotor with a large AC or DC motor :/

aydoll 04/19/2024 (Fri) 19:33:43 No.30970

It's the servo motors that make up the structure of this robot, the mistake was to set a structural basis and attach servo motors to it.

Chobitsu 04/20/2024 (Sat) 07:43:39 No.30971

>>30969 Heh, they are going to run into the whole power/mass ratio issue now, same as all the other humanoid robotics companies. Burning hydrocarbons is a very energy-dense way to motivate cars (or robots). Now they are taking the 'EV' pill, they will be on level ground with say, Optimus. >tl;dr BD has a long row to hoe now. But of course the perceived """superiority""" of their competition will probably light a bigger fire under the other vendors. This, ofc, should accelerate the eventual introduction of home-based service robots -> companion robots. All of them GH Surveillance-State Specials, sadly. >>30970 Great insight, Anon. I've been trying to think several design approaches for a while that take advantage of this very concept. Volume is certainly one of the several severe constraints we're all up against here.

Grommet 04/20/2024 (Sat) 10:53:38 No.30973

>>30969 >Well, the idea of using a rotary cylinder fueled by air or oil seems outdated now. I wouldn't be so quick to rule out hydraulics. I HATE hydraulics. I've complained about them a lot but...with the right valves they are super cheap and they solve a lot of problems. I much prefer straight electric but to have lifelike waifus hydraulics would be far easier to do and MUCH easier to mass produce. In the video here, >>30956 He talks about spending 35 hours straight soldering alone. One of the main problems with hydraulics in terms of efficiency , in machinery anyway, is that the pumps run all the time and bypass flow the extra pressure not needed. The problem is if a pump is set for max pressure and flow then when not using max, it waste an a enormous amount of power. But, if we use electricity to control a pump and have some accumulator to store pressure then the efficiency becomes much better.(So that no one whines, I note, yes "some" hydraulic systems have some control over the pump but most still waste some amount of energy flowing back pressure.)

Grommet 04/20/2024 (Sat) 11:02:06 No.30974

Here's an idea. First visualize one of those party toys that is a rolled up flat sheet-tube. You blow on it and it unrolls and makes a cylinder. So instead of blowing the inside and unrolling it, we have it full of fluid and compress it to push out the fluid. Roll it up. Long skinny bladder with an iron covering that can still roll up. We doing the opposite of the party blower thing. To operate it put an electric field on the end and the bladder will try to pull in the iron just like a solenoid. But since it's a long tube the only way to do so is to roll up, forcing out the fluid. This is srt of whacked "but" since all of your muscles would be made of badders and bladders could be cast "theoretically", for the whole body at one time with liquid plastics/rubber. Once you had the pattern you could churn them out.

Grommet 04/21/2024 (Sun) 01:54:34 No.30981

Since actuators are all tied up with the sensors to position them, a reference to a comment I made in the skin section that may be relevant here also. >>30980

Grommet 04/21/2024 (Sun) 02:10:47 No.30982

>>30974 >iron covering I wish to make this more clear because people may get the idea it's some big iron plate. No, it could be iron oxide particles embedded in silicon or rubber. If you notice while this is a different form I have not given up on the idea of inductive reactance motors. Mostly because they are cheap, fast, lightweight and powerful for their size. Yes you can do a little better with super expensive rare earth magnets but...they're super expensive and do you want a magnetic waifu that has metal sticking to it, I think not.

Robowaifu Technician 04/21/2024 (Sun) 03:17:58 No.30984

>>30982 force is proportional to mass, some dust isnt going to create a lot of force

aydoll 04/21/2024 (Sun) 11:23:36 No.30988

https://www.zygotebody.com/ There are so many muscles/actuators to set up for just one arm, and the deltoids are composed of three smaller muscles :o Indeed, it would be much easier to use only three large servomotors that control Yaw, Pitch and Roll rotations. https://www.aliexpress.com/item/1005003988911701.html However, the issue is that the rpm is really slow for acceptable torque: 24V, 11rpm, 85kg.cm Perhaps a 1000W Brushless DC Motor coupled with a gear set would do the job. But since I cannot find the gear set, I might have to build it myself, possibly with the help of the following website for delving into gear configurations and building custom solutions: https://drivetrainhub.com/gears/

Chobitsu 04/21/2024 (Sun) 15:12:11 No.30990

>>30988 Nice observations, Anon. Please continue! Cheers. :^)

Artbyrobot 04/22/2024 (Mon) 03:26:38 No.30995

>>30988 or you can downgear by way of pulleys instead of gears which will be a more quiet outcome and imo easier to make than gears. Just need small bearings and some scrap plastic and some string and a sewing needle and scissors as only tools.

Grommet 04/22/2024 (Mon) 05:35:15 No.30996

>>30984 >force is proportional to mass, some dust isnt going to create a lot of force No F=MA You left out the A part and the A in this case is due to the electromotive force on the, as you call it, dust. I assure you if you get between the "dust" and a 20 Tesla magnet you will feel some serious force.

Grommet 04/22/2024 (Mon) 05:47:44 No.30997

>>30988 >three large servomotors that control Yaw, Pitch and Roll Yes much easier but it would look too much like a robot to me. Obviously this is an issue with me, others might not mind this. Of course trying to replicate the muscles in a human body complicates things a good deal but...that's what I would find more attractive.

aydoll 04/22/2024 (Mon) 11:47:33 No.30999

>>30990 Thank you :] I've tallied up four large servomotors for one leg, so it might cost around 100 euros of servos, assuming each of them has a torque of 1 Nm: www.aliexpress.com/item/1005005428153048.html Cheers >>30995 Oh like a bicycle's gearing system, sounds like an interesting challenge to take on >>30997 Interesting thought, the tactile sensation of touching filament, indeed differs from the hardened material of servomotors

Robowaifu Technician 04/22/2024 (Mon) 20:41:40 No.31002

>>30999 I think it would be more like a stringbike rather than a normal chain and sprocket system wouldn't it? >>30995

Artbyrobot 04/23/2024 (Tue) 02:35:20 No.31004

>>31002 well not like a bike at all imo. A bike is downgearing by way of sprocket and chain. Even string and pulley in continuous rotation is not ideal imo. You want pulley blocks like these photos but way way smaller custom made with bearings and plastic discs and fishing line and super glue

Chobitsu Board owner 04/23/2024 (Tue) 15:52:03 No.31009

>>30996 This. The rare-earths are used to greatly 'amp up' the electromagnetic properties of the basic electro magnets themselves. Kind of like how you need trace (tiny amounts of) otherwise-often-harmful-micronutrients (like cyanide) for your cells to properly manufacture the incredibly-yuge swath of proteins vital for your metabolic processes, these trace amounts of rare earths significantly enhance magnets -- especially when they are at cold temps! (Say, around liquid nitrogen realms.) >>30999 Good luck aydoll! If I haven't yet given you the 'official' greeting yet, welcome! :^) >>31004 As a country boy, I'm quite familiar with block & tackle. It's absolutely amazing the force multiplier that can be achieved with this simple machine.

Robowaifu Technician 04/23/2024 (Tue) 23:50:08 No.31012

>>30999 For some reason the crotch reminds me of a robosapien... I think it is the slight angle where the codpiece meets the first hip joint.

Kiwi 04/24/2024 (Wed) 00:09:57 No.31013

Some Pulley adjacent actuators https://www.youtube.com/watch?v=6QEgNbaDCjw https://www.youtube.com/watch?v=utDagouxM5U https://www.youtube.com/watch?v=Bzsw-3sJ-I8

Chobitsu 04/24/2024 (Wed) 00:20:31 No.31015

>>31012 >For some reason the crotch reminds me of a robosapien... I think it is the slight angle where the codpiece meets the first hip joint. IMHO, this literally the most critical design spot on the entire robowaifu. Everything else depends on the pelvis/hip confluence being correct to function well as an overall bipedal locomotive system (not to mention snu-snu working properly).

Chobitsu 04/24/2024 (Wed) 00:23:03 No.31016

>>31013 Excellent resources, Kiwi. Thanks! :^)

NoidoDev ##pTGTWW 05/28/2024 (Tue) 05:18:44 No.31368

Tesla Bot Motors: https://youtu.be/5MNz0YyqgLY https://youtu.be/1xChD-gv_pc

Kiwi 05/31/2024 (Fri) 23:18:08 No.31403

Capstan actuators are cool, quiet, and efficient! https://www.youtube.com/watch?v=MwIBTbumd1Q

Grommet 06/05/2024 (Wed) 10:53:21 No.31432

>>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.

Grommet 06/14/2024 (Fri) 01:16:52 No.31576

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.

Grommet 06/14/2024 (Fri) 01:26:43 No.31577

>>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.

Chobitsu 06/16/2024 (Sun) 04:34:20 No.31594

>>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

Edited last time by Chobitsu on 06/16/2024 (Sun) 04:35:40.

Robowaifu Technician 06/18/2024 (Tue) 19:14:59 No.31624

>>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

Chobitsu 06/19/2024 (Wed) 00:54:04 No.31629

>>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

Robowaifu Technician 06/21/2024 (Fri) 22:31:41 No.31659

> post-related : (>>31657)

Robowaifu Technician 06/23/2024 (Sun) 09:50:57 No.31707

>>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.

Grommet 06/26/2024 (Wed) 09:40:28 No.31788

>>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.

NoidoDev ##pTGTWW 06/27/2024 (Thu) 07:30:06 No.31801

>>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.

Grommet 07/03/2024 (Wed) 01:40:14 No.31961

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.

Kiwi 07/03/2024 (Wed) 23:51:37 No.31978

>>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

Robowaifu Technician 07/04/2024 (Thu) 17:22:56 No.31998

>>31961 >>31978 Thanks, Anons.

Robowaifu Technician 07/04/2024 (Thu) 17:27:34 No.32000

> (actuators-related : >>31995)

Grommet 07/07/2024 (Sun) 00:16:19 No.32038

>>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.

Robowaifu Technician 07/22/2024 (Mon) 01:31:06 No.32328

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

Edited last time by Chobitsu on 07/22/2024 (Mon) 01:31:54.

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