How I remagnetized demagnetized neodymium magnets.

[yu_duk]

After my MSP burned out, all that was left was a burnt out motor with pedals. The idea arose to restore the wheel, I rewound the winding and restored it, but it’s not clear what to do with completely demagnetized magnets, buying a rim is not our method, but there was no money from buying a wheel that burned out. It turned out to completely restore the magnetic force of the magnet using a power transformer from an old 1 kW microwave oven, placing it between the cores while shorting the high-voltage winding of the transformer, and applying 220V to the primary voltage through the diode bridge, turned on for 5-10 seconds, the transformer gets very hot. And so I magnetized all the magnets and already drove 2500 km on it.

[yu_duk]

[Rawnei]

Awesome! Whenever the post Apocalypse is here now I know who to turn to to get my wheels fixed!

[0000]

I know there's some design tradeoffs for motor characteristics like efficiency and torque produced based on the strength of the magnets used (among other things). Do you know if re-magnetizing returns them to the same strength, or is the resulting magnetic field strength influenced by the time on and power applied to the transformer? A couple ways to compare if you had an original magnet sample is to test with a magnetometer or a force gauge at holding each magnet at equal distance, but not something most people have just lying around. I don't anyway. Just curiosity speaking, it's a very cool repair. Good enough to just have it up and running again.

But who knows, if things continue to go sideways to the point where global trade breaks down, it doesn't hurt to know the most ideal way to resurrect rare earth magnets as I have 3 PEVs I'd like to keep running in the long-term.

Also, how'd you get the magnets off without damage? Assuming they weren't completely dislodged from the fire, heat the outside shell with a torch to weaken epoxy?

Edited September 10, 2022 by Vanturion

[yu_duk]

The magnetization time had no effect, it did the same result for 2 seconds and 30 seconds, compared the magnetization force with a pair of surviving magnets by magnetizing the knife with hanging loads on it, the magnet was weaker than the others, I tried to remagnetize it by heating the flame of the burner to the Curie point, but it is larger apparently he was born that way, it is important if the magnet is slightly magnetized, then polarity must be observed during magnetization. I knocked the magnets from the rim one at a time into the end with a hard wooden bar, then re-glued them to the epoxy. And the final test is an assembled wheel that pulls 150kg (I have a 100kg wheel of 45 kg and equipment) uphill at a speed of 65 km/h, maybe faster, in the air it spins up to a speed of 104 km/h, in my opinion this is a good proof that it works, although I myself didn't believe it was possible. The wheel really came out as if from a post-apocalypse) and it was also possible to deceive the black Begode RS controller by increasing the current limit at the start to 300 A.

[0000]

4 hours ago, yu_duk said:

The magnetization time had no effect, it did the same result for 2 seconds and 30 seconds, compared the magnetization force with a pair of surviving magnets by magnetizing the knife with hanging loads on it, the magnet was weaker than the others, I tried to remagnetize it by heating the flame of the burner to the Curie point, but it is larger apparently he was born that way, it is important if the magnet is slightly magnetized, then polarity must be observed during magnetization. I knocked the magnets from the rim one at a time into the end with a hard wooden bar, then re-glued them to the epoxy. And the final test is an assembled wheel that pulls 150kg (I have a 100kg wheel of 45 kg and equipment) uphill at a speed of 65 km/h, maybe faster, in the air it spins up to a speed of 104 km/h, in my opinion this is a good proof that it works, although I myself didn't believe it was possible. The wheel really came out as if from a post-apocalypse) and it was also possible to deceive the black Begode RS controller by increasing the current limit at the start to 300 A.

Nice, thanks for the tips.

More questions if you don't mind!

• Did you do any other mods while you performed this major motor surgery? Some things I thought might be interesting if I ever got into it:
  • Statorade
  • Upgraded/larger phase wires
  • Changing motor winding configuration and/or increasing copper winding fill density

One thing I didn't quite follow there at the end - "deceive the RS controller," so you've changed the current limits of the motor controller? I didn't think anyone hacked it yet to be able to change the phase current limits. Although I've been metaphorically slapped here a couple times with knowledge and data for trying to treat the EUC controllers like ebike controllers so I could still be thinking about how these controller limits are set wrongly.

From RagingGrandpa's EUC pull tests, most of the performance wheels have peak current limits at the low-to-mid 200 Amps. If you've increased that limit to 300A, that is very interesting. Please, feel free to share more on this.

Edited September 11, 2022 by Vanturion
bad wording

[yu_duk]

6 hours ago, Vanturion said:

Хорошо, спасибо за советы.

Еще вопросы, если не возражаете!

• Делали ли вы какие-либо другие модификации, пока выполняли эту серьезную моторную операцию? Некоторые вещи, которые я подумал, могут быть интересными, если я когда-нибудь вникну в это:
  • Статорада
  • Модернизированные/увеличенные фазовые провода
  • Изменение конфигурации обмотки двигателя и/или увеличение плотности заполнения медной обмотки

Одна вещь, которую я не совсем уловил в конце — «обмануть контроллер RS», так что вы изменили пределы тока контроллера двигателя ? Я не думал, что кто-то еще взломал его, чтобы иметь возможность изменить ограничения фазного тока. Хотя меня несколько раз метафорически шлепали здесь знаниями и данными за попытки обращаться с контроллерами EUC как с контроллерами ebike, я все еще мог думать о том, как эти ограничения контроллера установлены неправильно.

Судя по тесту RagingGrandpa EUC на растяжение , большинство рабочих колес имеют ограничения по пиковому току в диапазоне от низких до средних 200 ампер. Если вы увеличили этот предел до 300 А, это очень интересно. Пожалуйста, не стесняйтесь делиться информацией об этом.

Yes, indeed, I modified the stator winding in thickness, wound it as tightly as possible, it turned out to wind a beam with a cross section of 5.5 mm2 from a native C30 beam of 4 mm2. The configuration of the windings exactly repeats the original one, I wound it for the first time I was afraid to make a mistake I filled the windings with several layers of varnish and then dried each layer with epoxy resin by connecting the welding machine to a current of 10-20 A. There was a moment that my magnet cracked, I combined it from two and glued it on the rim, the main thing is that where the sensors were all exactly. And the current increased by adding another shunt to the phase current sensors, and all the talk that it was dangerous turned out to be in vain, the wheel keeps the balance, the logic of work has not changed, but I have already driven 2 thousand kilometers with 3 shunts) Yesterday, driving behind the car, I didn’t notice a big hole on the road and hit into it, the wheel hit hard but left normally, on two it would have sold by current and dropped (there was experience), and here only a slightly bent rim.

[yu_duk]

Edited September 11, 2022 by yu_duk
Images

[yu_duk]

Just now, yu_duk said:

This is with regard to the increase to 300 A;)

[0000]

49 minutes ago, yu_duk said:

Yes, indeed, I modified the stator winding in thickness, wound it as tightly as possible, it turned out to wind a beam with a cross section of 5.5 mm2 from a native C30 beam of 4 mm2.

Fantastic, nice job! I've read others attempts on this with similar e-bike motors elsewhere, but for their efforts never saw such a large increase in copper fill. Also speaks to inefficient winding density from motor manufacturer... so it goes.

53 minutes ago, yu_duk said:

And the current increased by adding another shunt to the phase current sensors, and all the talk that it was dangerous turned out to be in vain, the wheel keeps the balance, the logic of work has not changed, but I have already driven 2 thousand kilometers with 3 shunts)

Oh wow, that's super interesting. And with you're lipo pouch cells, thicker wires, increased copper fill, and custom BMS looks like you can squeeze a good amount of performance over stock. That's really cool man. Thing looks like an all-weather tank!

Voltage sag has got to be much less too, what are you hitting top speed now? I don't think you can call that an RS anymore. How about RS S.S. (Super Soldier) 19, if the translation doesn't botch it anyway, LOL. Just a thought .

[yu_duk]

3 minutes ago, Vanturion said:

Фантастическая, красивая работа! Я читал другие попытки сделать это с аналогичными двигателями для электронных велосипедов в других местах, но их усилия никогда не видели такого большого увеличения количества меди. Также говорит о неэффективной плотности намотки от производителя двигателя ... так оно и есть.

Ого, это супер интересно. А с липо-мешками, более толстыми проводами, увеличенным медным наполнением и индивидуальной BMS, похоже, вы можете выжать хорошую производительность по сравнению со стандартной. Это действительно круто, чувак. Вещь похожа на всепогодный танк!

Падение напряжения тоже должно быть намного меньше, какая у вас сейчас максимальная скорость? Я не думаю, что вы можете назвать это RS больше. Как насчет RS SS (Super Soldier) 19, если перевод все равно не испортит, LOL. Просто мысль .

Thanks for the praise The speed in the air is 104.2 km/h, I drove a little more than 70 km/h, and the speed is about 70% at this speed, the Leaf battery with a balance of 50%, heavy with high current output.

[yu_duk]

1 hour ago, Vanturion said:

Я не думаю, что вы можете назвать это RS больше. Как насчет RS SS (Super Soldier) 19, если перевод все равно не испортит, LOL. Просто мысль .

Thanks for the idea, I used it

[Mark13i]

When I was reading this thread I felt like I was watching another movie "Mad Max"

[Robse]

1 hour ago, Mark13i said:

When I was reading this thread I felt like I was watching another movie "Mad Max"

Same here

[litewave]

This is awesome work - thank you so much for sharing!

We have become so obsessed with EUC-consumerism on this site, it's inspiring to see the hacker culture make a comeback here!

[yu_duk]

2 hours ago, litewave said:

Это потрясающая работа - большое спасибо, что поделились!

Мы стали настолько одержимы EUC-консьюмеризмом на этом сайте, что вдохновляет видеть, как хакерская культура возвращается сюда!

 Litewave, thanks for such a great review. For me, destruction was a spark for creativity, one month was very saddened by the loss. Then, little by little, he began to create, during the day he worked at his main job, and in the evenings and at night he created. It started with rewinds, and when the magnets recovered, I realized that I could do the rest easily. And what a miracle it was that when turned on after 2 months of operation, it did not explode, but kept its balance;)

[daniel1234]

So awesome project - I would not guess that you will remagnetize then all in same grade. But seems you have some major skills ! 

[yu_duk]

14 hours ago, daniel1234 said:

Настолько офигенный проект - я бы не догадался, что вы перемагничиваете потом все в одном классе. Но, похоже, у вас есть некоторые важные навыки! 

Nothing special, just an electronics engineer, all this for the first time it turned out to be magnetized by accident, it just didn’t work with a coil, no matter what I did. I took the transformer and closed it in a vise, twisted the high-voltage winding and turned it off, and everything worked out, only then I realized what I had done, I could have consciously come, but what would have been saved. A transformer with a shorted secondary coil operates at 100% power, unlike a simple coil or an idling transformer, that is, in this case, the magnetic flux at the core gap is maximum.

[meriwald]

On 9/11/2022 at 12:17 AM, yu_duk said:

with 3 shunts

Where does the third shunt go? There are only two current sensors with two pairs of r001 resistors. Where do you put one extra shunt ?

[yu_duk]

1 hour ago, meriwald said:

Куда идет третий шунт? Датчиков тока всего два с двумя парами резисторов r001. Куда поставить лишний шунт?

I saw 3 shunts for one phase, in addition, you need to install and purchase 2 shunts! as in the photo

[yu_duk]

4 minutes ago, yu_duk said:

Я видел 3 шунта на одну фазу, дополнительно нужно установить и приобрести 2 шунта! как на фото

[meriwald]

@yu_dukggot it 👍 thx

I see all your quotes are in Russian, are you using this forum through translator ?

[yu_duk]

20.09.2022 в 00:11, меривальд сказал:

@yu_dukпонял 👍спасибо

Я вижу, что все цитаты на русском языке, вы включаете этот форум через переводчик?

Yes translator via

[UtahRider]

On 9/10/2022 at 1:05 PM, yu_duk said:

After my MSP burned out, all that was left was a burnt out motor with pedals. The idea arose to restore the wheel, I rewound the winding and restored it, but it’s not clear what to do with completely demagnetized magnets, buying a rim is not our method, but there was no money from buying a wheel that burned out. It turned out to completely restore the magnetic force of the magnet using a power transformer from an old 1 kW microwave oven, placing it between the cores while shorting the high-voltage winding of the transformer, and applying 220V to the primary voltage through the diode bridge, turned on for 5-10 seconds, the transformer gets very hot. And so I magnetized all the magnets and already drove 2500 km on it.

Wow! See what you can do when you have to or really want to? And my mindset when I get a flat tire is to start shopping for a new wheel. I’m ashamed.

 

@yu_dukImpressive work and very ingenious, especially using the microwave magnetron as a transformer!

[blox1130]

@yu_duk have you considered using a VESC like ubox from Spintend instead of premade EUC controllers? VESC is programmable, and I think someone like you would appreciate the versatility. I'd also like some updates on your work if you consider using one!