2223 Crab Claw Alternators With Permanent Magnets As Generators

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links to credits
Gadget Addict - • DIY Wind Turbine Update
Monea Ltd - • Alternator disassembly
TecnoDesarrollos - • Cómo Abrir el Rotor de...
Hurricane Wind Power - • Permanent Magnet Alter...

[@AtlasReburdened]

I have an alternator that works like this, but both the field coil and the stator coils are stationary, and the claws simply rotate around the field coil. So there's actually no need for for slip rings or brushes anyway, but apparently the added complexity of that setup makes it cost more than just adding current carrying wear components and knowing that the customer will have to deal with it later. If I recall correctly, the alternator is part of the conversion kit for turning a Ford F350 into an ambulance, so it's designed to be rugged, hence the lack of wear components. It also has a neat feature in that there are extra diodes for the star points, which stray from 0V at some point going up the RPM scale due to the reactance and resistance of the coils. This does the almost magical work of making the coil arrangement star at low rpms, giving the volts needed for equipment at idle, and delta at high rpms, which gives gobs of amps at reduced(but still high enough) volts. The alternator really is a beautiful piece of engineering, which I'm certain that ford had absolutely nothing to do with😂😂😂.

[@lawrencefoster5608]

I've always heard that the alternator is a amazing thing.

[@bartronicsecurity]

If you do decide to modify an alternator it would be a good idea to replace the shafts with a stainless steel or other non magnetic material. Reason is that it is magnetic and will buy pass some of the magnetic field resulting in a weaker field at the fingers. This is a lesson I learnt when I did this experiment. I got 240 W at 8000rpm with the original shafts and 1200W at 8000rpm when I put in a non magnetic shaft. If you have a magnetic field strength meter you can actually measure the difference.

[@ogi22]

Very good tip! I sometimes wondered if there is some magnetic flux losses due to the shaft. Now you got me an answer, thank you 🥰

[@justtinkering6713]

I'd like to see a wind turbine survive 8000 rpm, yikes! I still like axial flux because the fingers have a reluctance and distance from the coil center matters, ie: inverse square law. So still thunderbolt 3 phase for me, 12 magnets and 9 coils.

[@bartronicsecurity]

@@ogi22 Just remember one thing. Putting in a maget in the rotor does make it harder to start turning initially as magnetic coging takes place. But once the rotor starts it works like a flywheel. This coging gets harder and more noticable with a non magnetic stainless steel shaft than with the original magnetic shaft which makes sense.

[@ogi22]

@@justtinkering6713 That's what gear box is for 😉

[@ogi22]

@@bartronicsecurity It does make sense. If much more field is directed to claws, then it should be normal.

[@ivekuukkeli2156]

Excellent presentation. In a sense: turbo speed physics course.

[@freemanrader75]

I can’t thank you enough for all of the help you have provided me with during my personal tinkering 🙏. Our line of exploration must be very similar.

[@McRootbeer]

Anybody else wondering if conductive ink could be used to make the crab claws? If we could, axial flux motors and generators would become a whole lot cheaper and easier to make for the home builder.

[@WarkWarbly]

I have, but I think the reason other metals are used is because of their natural reluctance. Reluctance is kind of like resistance, resistance resists current and reluctance resists a magnetic field (though it doesn't inhibit it but rather turns the field by 90 ish degrees). Ferrous metals and copper have reluctance patterns and behaviors that tend to produce the desired results. Carbon, and inherently graphene conductors tend to pass the current/voltage readily enough that there isn't much of a "zigzag" pattern to the flowing electrons. This lack of reluctance is not ideal for motors or generators. This is why I laugh at people when they say superconductors will change the way power is delivered. While they'd be awesome for delivering power through public lines, they'd be terrible for a generator as you need a bit of reluctance to force the electrons to actually dance about.

[@justtinkering6713]

​@@WarkWarbly The denser the atoms are packed the less the reluctance. Iron is great, iron powder mixed with resin is bad .

[@McRootbeer]

@@WarkWarbly do you think changing the shape of the ink lines to increase distance, or adding metal salts or other additions to increase resistance might help improve reluctance?

[@imfloridano5448]

The density of the metal is wat is important for the crab claws. The ink would probably work for a mini generator

[@jameshatton4211]

I was thinking about regen braking 100% on a 28Kw electric bike hub motor? 🤔 Then having a shaft to either wind turbine or a syngas motor? Use the electric clutches off toyota GZE super chargers to engage or disengage drive to the input shaft?

[@8ank3r]

Great stuff as always Rob. Cheers

[@Peter-jo3wt]

The Hub motors from hoverboards make incredible generators as well.

[@christopherleubner6633]

Yup those make awsome windmill generators. Just use a 3 phase diode (6 diodes in 3 pairs back to back. Makes 24V at about two amps with moderate turning. OCV is about 36V and SCC is about 6A. Definitely need to use a charge regulator with those. Also they can be mounted on a bike to give auxiliary power when peddling ❤

[@patrickday4206]

Or an old Flux capacitor 😂

[@niklar55]

Very informative, and useful presentation. Thank you. 😊

[@icebluscorpion]

Rob look out for the German company Mahle, they were primarily specialized in building pistons but now they make electromotors too. They did replace the commutator with a induction coil like for charging phones but beefier. No slip rings there. All benefits of a powerful Universal motor without the downside of replacing bruches because there aren't any 😂.

[@hoodedcreeper2465]

I've looked into them the inductor is basically just a reshaped transformer. That would probably work pretty well here because there isn't any need to rectify the secondary.

[@TheMadManPlace]

Those fancy (albeit powerful) magnets are darn expensive so for a cheaper option use old speaker magnets. They are mostly free at scrap yards. What I have often wondered is if you built up the outside of the claws with a welder and then turned them down so that the gap between them and the stator coil assembly was reduced as much as possible would you get a significant increase in output power. And then taking it to the extreme, grind the inside of the stator assembly plates smooth and concentric to the bearing housings and you could probably get the air gap down to a ridiculously small clearance. However you might just be creating a siren.

[@christopherleubner6633]

The ones from microwave ovens are free as well, and have a much stronger field and are a perfect fit on the alternator shaft. I just carefully drill three of the claws on each side enough to fit a small RE magnet into it then set it in place with JB weld. It gives enough energy to self start the alternator allowing it to operate at far lower RPMs.❤

[@blue_beephang-glider5417]

Haven’t been watching long, never knew about these. 🙂👍

[@user-xl2sh9qs5f]

Did you notice the slit on the metal under the coil? This cancel the bemf of the coil, that's why the coil is not hot.

[@rhiantaylor3446]

The efficiency of car alternators is generally understood to be poor at about 50% (despite what Wiki reports of claims from Bosch). I have often wondered what would happen to efficiency if the energising coil were to be replaced by a permanent magnet as you have done. Efficiency is less important than cost in a car application but to capture wind energy I guess we would spend more if we could double the alternator's efficiency and thus output.

[@mangjay80]

Good idea

[@lawrencefoster5608]

I like the idea of steam power.

[@gaiustesla9324]

exquisite insights

[@davidvwilliamson]

i read 'the jungle is neutral' by spencer chapman he was stuck in the malayan jungle for about 3 years hiding from the japanese. they had a radio transmitter but only a flat battery it took them months & months to find a way of charging this battery enough to get a radio signal out

[@simonsimon-gq3rk]

super comme toujours! mais comment calculer la puissance nécessaire de l'aimant (kilo ou teslas) qui remplace le bobinage du rotor (dans le cas d'un alternateur auto de 1000W par exemple)? merci

[@tubularguynine]

I replaced the wound rotor in a chevy alternator with a 14-magnet rotor I got off of eBay, and that thing will produce 15 to 20V DC just by clamping a small vice-grip pliers on the shaft and spinning it with my hand! ⚡️

[@Living_Water274]

Cool

[@merinummi9123]

The video you're referring to (1534 bending magnetis fields) is missing from your video list, videos go from 1533 Supercapasitator mathematics to 1537 Turning cheap metals to expensive ones. What's up with that, and where can I find the original 1534?

[@haroldvanveldhuizen9525]

.

[@ThinkingandTinkering]

try now it is 1534 (M) bending magntic fields

[@thewatersavior]

Would 3D printing the crabclaw with conductive filament have any benefits?

[@af0ulwind115]

I am curious as to how much impedance is caused just by winding the wire back over itself instead of running multiple parallel lines on the same circuit?

[@McRootbeer]

Hey Rob, would you have any interest in making a members video/series on getting started in electric motor/generator design? How to design for specific application needs, what size magnets/wire to use, how to estimate power output, etc...?

[@ThinkingandTinkering]

for sure mate

[@johnschneider931]

I keep thinking that the least costly energy solutions are going to be based on shape. I keep thinking of combining complemery tech is going to do this for us. Rube Goldberg for energy generation. A shroud to gather wind on a east west facing vertical wall covered in solar cells, wind cooling the panel on sunny days, on hot days the wind tower becomes a solar chimney drawing air up through the wind turbine and solar dominating the mix. Add in hot and cold storage and shaped aerogel to protect stucture, or maybe charged wood for heat and waterproof.

[@MartinMoleski]

First to view, like, and comment. Thanks for your work!

[@bensqaashow5857]

Mid to late 1970's Kawasaki KH440 and z400 use "Claw Pole Alternators"

[@silverpc4611]

You could just turn the crab claws and leave the magnet and coil stationary. Kind of like the Mighty mite.

[@justtinkering6713]

Cant find your $4 ac powered fan anywhere. Help

[@jesascaniusthusgaard5927]

Does someone kind outthere by any chance have a link for such a powerfull magnet ready to be bought and slapped in instead of the coil, would like to test it and try it out, have made a good windmill with ready gear from bicycle to run through a gear and then to a good generaator that makes power with rather slow rotaitional speed, i would be most thankfull :-)

[@somebeinganonymous]

So what would be the point stripping the coil out of the centre of the alternator? Why not just leave the inner coil intact, and install a permanent magnet surrounding the crab claws? I e the outsider version?

[@Hakanxyz]

Hi there. Did you ever tried leyden jar as energy storage?

[@AtlasReburdened]

They have exceedingly low energy density, as theyre effectively just parallel plate capacitors.

[@TerrorTubbie666]

Did you know AXA HR bicycle-dynamos are crab claw generators too??? (They are called AXA HR in the Netherlands, probably different names in other countries. If you know the name in your country, please add a reply?) Fun fact: If you reduce the size of the fingers of the claws to about ⅓ to ½ the original size, you can replace the lightbulbs in the front&rearlight by single LEDs. You'll see you'll be riding your bike with lights on in daylight, because it's so fr*king funny you don't feel any resistance of the dynamo anymore, while still producing enough electric energy to clearly have your lights on, in daylight! 😂😂😂

[@TerrorTubbie666]

By the way: There are probably a lot of other brands and types of bicycle dynamos that you can modify the same way to have the same super funny experience. But I like to use these because axa makes it very simple, I think. Extra tip: If there's no screw or nut on top of the wheel of the dynamo, it is pressed on. Just pull it while wigling it a bit or pry with a flat screwdriver between the wheel and the body of the dynamo. And you don't need a torxbit for the bottomscrew of the axa. A flat screwdriver will do just fine.

[@Crftbt]

It says 1080p, but why does it look like 240p?

[@patri0t1776]

Got a link to that fan for 4 bucks? I'm finding them and cheapest is 10. I'm in the States.

[@Thunderstormworld]

I bought one and in a gust of wind off about 25kph produce 220 volt but about 0.5 amps.

[@jamest.5001]

I been wondering if a alternator could be excited. By putting a small ring magnet witht the field coil. Then usethe output through a high power resistor . To sdjust the voltage to the required range. Or possibly use a lightbulb. and possibly use the semiconductor fuse things, can't thinkbl of what they are called, They go high resistance, then suto reset, i was thinking maybe use one or two to work as a safety regulator with a relay, the current goes so high. Trips the fuse that adds a load to the turbine through a relays normally closed side if the output is exceed, in high winds. However, the main thing is will the field still work with a magnet making it self excited.??

[@Chris-op7yt]

make a whole bicycle wheel a generator, that powers a assistive motor for the bike

[@vylbird8014]

Why magnets? The great advantage of a field coil is that you can use feedback to regulate the current, and thus the output voltage. And the field coil goes on the rotor so the slip rings only have to handle the comparatively low current.

[@themeek351]

The Chinese probably got the idea from watching your channel!

[@byronsowntime]

I think a regular alternator and rectifier would be cheaper to make and then spray the inside with marine lacquer to weather proof it. Then its up to the blades you would need. We have thousands of alternators in junk yards around the world and its just a question of as you would guess a revolutionary turbine to drive it and store the energy.😎

[@AtlasReburdened]

Sure, but you need a regular alternator to spin at 3600 RPM for peak output(if I remember right), and if you spin a turbine 60 times a second you'll get shrapnel instead of power.

[@byronsowntime]

@@AtlasReburdened I have built 2 in the past. They next kick at peak performance but they do move and after many hours of rotation the batteries charge and the dump load heats the water tanks. I guess if its efficency we are after and not easey fixing... It's magnets every time. But... They ain't cheap.. Peace man... 😁 Don't forget to marine lacquer

[@daverichardson9413]

Saw a pic if what thought was coil of mig welding wire... wonder if you could use them as is in a electric thingy..ha can't think what right now.. anybody?

[@pauldent3059]

Saves having to glue a ton of little magnets in alternative poles

[@robinhooper7702]

Excuse my ignorance but an alternator produces electricity without modifications, No? If I understand it correctly. When you turn/spin the pulley, voltage comes out. Yes? Isn't that how it works in a conventional vehicle?

[@justtinkering6713]

Thunderbolt alternator

[@frankfaubert1927]

$40 CDN on Amazon or 23 GBP. You're still winning compared to Canada lol.

[@ThinkingandTinkering]

it is still a silly price lol

[@TuttleScott]

without bearings I wonder how long they'll last.

[@christopherleubner6633]

The easiest way to make an alternator self exciting is to carefully drill into the crab claws, only 3 per side, then secure small neodymium magnets in with epoxy ensuring they are installed respecting polarity. When it spins it generates enough current to excite the magnetic exciter regulator without overloading it at lower RPMs. The electromagnet generates a far stronger field than even a rare earth magnet of similar size. ❤

[@robinhooper7702]

I'd like to follow your train of thought. Do you happen to have a vid or more detailed description of what you are referring to? What do you mean by 'only three per side'?

[@TerrorTubbie666]

4:36 wait, what?!?!?!? Why would you want to replace the coil by a magnet to make a windturbine??? Just attach the axle to something sturdy and put blades on the housing.

[@justtinkering6713]

$17 on Amazon

[@OldManSparkplug]

under what search term?

[@justtinkering6713]

@@OldManSparkplug portable ceiling fans

[@lezbriddon]

In rider out rider is losing popularity to the Americanised in runner out runner.