Yep, buyers beware. I was not that surprised from the result, but you always have that hope, that the other sellers just charge too much... But with grade N52 there are no cheap solutions in the manufacturing :( Thanks for watching!
The sellers are just crazy. Lasers are sold overpowered and dangerous without any safety, as we know from your previous video, and things like flashlights and as i see even magnets are underpowered...
You are welcome. This is my first attempt at determining the grade of magnets. I may refine or polish the method in the future. Especially based on feedback from viewers who most likely will have some input :)
This is my last comment regarding this I swear: Here is how you make a ferrolens: find 2 panes of FLAT glass (I eventually added a third layer of glass). They need to be really flat or you will end up with bubbles. Optic flats are best, but pricey. Then mix 1:1 ferrofluid and WD40. Shake up the mixture and then let it sit to get bubbles out. Then add this mixture ( you dont need much) to one pane of glass. Then slowly lower the second pane on top of the first one. This makes a super thin layer of the mix. Now you just need to mount the panes of glass in a black lined box (i used a shoebox) and light from below with multicolored or white LEDs. Now get a magnet and see the cool instintaneous changes. These arent the field lines, but some other representation of the magnetic flux (i didnt look into it too deep, gets technical fast). Checkout my videos on it. There are one or two how to builds on UA-cam as well which show you how to make one. Hope you at least google it. Thanks again!
So....Did you check it out? Its right up your alley. Come on..Love your content by the way. Using my radiascan to analyze my uranium glassware. I told Smart Elements that I was refered by you. Im a fluorescent mineral collector, so i appreciated the doped beads that glowed. Checkout tenebrescence if you want to see a cool trick with some special minerals (i have a video on that too if you dig around). You need to upgrade your UV sources! That germicidal lamp just wont do, you need a good shortwave ultraviolet lamp. They are pricey, but well worth it. I'm going off on a tangent though, make that ferrolens!
I'm glad to see that you're doing well during these dark times! Your videos are always interesting and teach me something new whenever I watch one. Stay safe out there and best of wishes for your experiments in the future!
Hehe. In many cases true, but I do like eBay. You can get so many things there, that are impossible to get anywhere else. Good for a guy with alternative interests like me x) But buyers beware. Safety is rarely a concern in the cheap products and if it is too cheap to be true, then... Thanks for watching!
eBay May well be a trash can but if you take all ratings with a pinch of salt then you can score some good deals. If it says 8amp chances are 2amp is fine.. and you can buy stuff cheaper than you could buy the parts or any of the individual parts.. You can get a pwm 8amp rated dimmer for £1.32 delivered. You can’t buy the box for that or the control knob or the components lol and it’s not 8amp that’s for sure but for controlling led lights it works ok... Just don’t buy stuff you may need to rely on...
Great video as always! Yes, I would like to see you grade the ring and sphere magnets with your method. Quarantine's keeping us in, and we might as well keep ourselves entertained and educated with videos like these!
Thanks, Sir. I am not in quarantine here in Denmark, so I don't have more time to make videos than usual. But more videos coming every month! I will attempt ring and sphere magnets too. The sphere magnets are very sensitive to even small changes in sensor distance etc. so I need to be even more careful...
7:18 I just use a measuring compass and or calipers. you just set the radius close enough by eye (you can dial it down even more after) then swipe from at least 4 opposite sides of the circle. very simple and easy, the 4 curved marks will always meet up at the center. you really only need 3 marks, but 4 is easier and extremely accurate when finding opposite sides by eye. maybe there is a easier way though, but after finding the center in only couple seconds and drilling it, I get +/- 0.02mm run out in the lathe.
If you had a known thickness perspex that you place between the probe and the magnet under test, then small variations of coatings etc. will be less of an issue. Love the insight you provide on magnetism.
Not a bad idea. I will do further testing - including how accurate the formulas are at a farther distance over the center. This was the first test - I may improve the method on feedback like yours - thanks!
We faced a similar problem with neodymium magnets. We produce ebike and e-scooter motors and therefore these motors have strong magnets inside to produce large torque. In fact some magnets we tried were about 1.5x short of their claimed field strength (magnets were labeled as N38) so the motors were badly lacking torque and overheated. Then we chose another magnet supplier to buy similar grade magnets and then motors were able to match expected characteristics.
I am not surprised. It is hard to determine the grade precisely without good equipment, so many manufacturers may be tempted to exaggerate the grade -expecting customers not be able to test it. Thanks for sharing a real life problem with low grades. Glad you found a good manufacturer!
Sonofagun, this is the kind of stuff to watch each day, every day, to actually learn something, instead of the usual drivel found these days on UA-cam. Good job, Brainiac! Have been a strong subscriber for many years now and will continue to do so! I wish I was able to support you through your Patreon, but I live in a goddamn ridiculous country that has not yet developed any such ways to make international payments/purchases..... Until that day comes, I'll always be a member of your insanely awesome club! Cheers!
Thanks, same to you. Though I haven't been gone for longer than usual. Did you miss one of my videos: ua-cam.com/users/brainiac75videos Otherwise you know the drill: Subscribe and click the bell, all notifications ;) Thanks for watching!
Very nice. This video feels so much like how the amateur laser hobby was in the early 2000's (ie, 2003) when we basically had no means of testing the optical output (watts) of a laser diode or module. Or the optical output (lumens) of LED flashlights. It's nice for a hobby to finally acquire access to testing the outrageous claims made on eBay.
I allways enjoy your videos mate ! keep doing what you doing and since i am driving through Danemark in a week i will buy a magnet in your honor, happy summer and stay healthy!!!
Please, please make a ferrolens! Its a gadget you can make at home using two panes of glass with a super thin layer of ferrofluid mixed at a 1:1 ratio with WD40. In the presence of a magnetic field the ferrofluid creates tiny thin lines which act like a diffraction grating. This creates a cool 3D holographic effect when lit by leds from below. I made one and it is so awesome. I have some videos about it on my channel. Just go back a couple months. But please make one. It is so worth it. It is sold commercially as Ferrocell by its inventor, but is easily made at home with common items (except the ferrofluid, but you must have some of that on you). Love your videos btw. I ended up buying a radiascan 701 and the glass bead element collection too. So cool.
Hi Jared. Ferrolenses do look good. Visualizing the beauty of a magnetic field, so I might attempt it. I just know messing with ferrofluid is always... messy. Glad you like my videos and end up experimenting yourself :)
@@brainiac75 I love your videos! I hope you brave the mess (I'm not going to lie, it can easily get messy). I have a bunch of random videos on my channel(that no one is watching), but if you find the one where I put repelling magnets on the ferrolens. It makes this awesome vortex/blackhole looking thing in the middle of them. Also checkout the video with the ring magnet, they look amazing on the ferrolens, making this spirograph looking pattern in the hole of the magnet. I bought a ring magnet specifically for this. I am glad that you checked it out and were kind enough to take the time to reply to my comments. While I have you, have you checked out the RGB laser pointers they have out now? They have actually been out for a couple years now, but i picked up one from Sanwu and another cheaper one from another website. They are really expensive, but you can mix the red, green, and blue(as you know) to make most the colors including white. I know you like lasers, and the one from Sanwu comes studded in tritium vials! They have one special one made of damascus steel(that is ridiculously priced) but comes with 98 tritium vials studding it! My radiascan goes crazy with my laser which has a dozen of them on it. Anyway, this reply is going on too long. Thanks
Almost always true, but there are exceptions. The cheapest highest quality bearing is currently, and has been for a long time, the one that is used in skateboards (608ZZ). Because that one bearing type is used so much globally (They are mass produced in greater number than any other bearing type) the price point has dropped to be much much lower than any other bearing of similar size and the quality has actually gone up over time. People who design new products look for existing high quality parts in current mass produced items so that they can reduce costs and use higher quality parts in their product by piggybacking on someone else's design who is buying so much of that part that the price point is lowered as production is ramped up to meet demand.
@@itsevilbert Yeah maybe, but science and engineering equipment (such as these magnets) is not exactly mass produced, because there is not that much demand for it. That stuff have to be higher quality as well, because low quality (or outright counterfeited) stuff is useless in those fields. The clients who needs such equipment are usually more solvent than many private individuals. They don't need to do that ugly busyness with some random untrusted/unknown 2nd hand crap. They either know what and from whom they buy or they just don't buy. If professional want to save money they buy 2nd hand from other trusted professionals. It has to be a lot cheaper though, because they also account the expensive value of labor for the extended product validation/checking/refund process the into the transaction...
@@userPrehistoricman Yeah, these are called Intel or Apple. Companies for professional Science/Engineering equipment however are probably a bit more trustworthy, because they know that their clients aren't stupid. Reputation is key in these fields, so they think twice about fucking their clients over.
You should also measure the leading edge of each magnet; as this is the area which has the greatest concentration of magnetic lines of force. That is to say that when you look at either face associated with the north or south pole and move from the center of the face to the edge where either the north and south meet one of the side faces; that edge has the greatest flux density. I would suppose that you might actually find that a magnet which seems to have a very low gauss rating when measured at the center of the pole has a noticeable higher rating at the edge, and you may even come up with different results when comparing different magnets in this way. The north/south poles as well as the so called bloch wall, are almost like termination points of the lines of force composing the field, and if the strength of field is determined by density of lines of force; then you are by definition measuring the strength of said magnets at their points of least concentration of lines of force.
Would like to see your calculations if you use a greater distance, say 10 mm, rather than "contact" distance between the surface and the magnetometer probe. Would it give you smaller uncertainty in the distance measurement? Love your experiments! Btw, I keep reviewing your series on para/diamagnetism of elements, especially those noble ones. Have you thought of testing metals as colloidal suspensions? Some can be easily made by shorting and sparking electrodes made of the metals in/under water. How would the (nano)particles react to a strong magnet?
LibreOffice is free and open source and LibreOffice Calc does a really good job. It's good to have it around when you don't want to go online for a mere simple spreadsheet.
Thanks for sharing. The shown spreadsheet is available both as an excel and open office document. I just downloaded the Excel version and opened it in Google Sheets. Works fine for me :)
THAT EVIL GIGGLE! This is why I like this channel. You've kept your soul and heart intact and haven't sold out to be a souless freak like most youtubers nowadays.
Hey Brain, I just have a doubt can you clarify? What would be the Gauss value if the polarity was divided between 50*50 /2 like Half South polarity and half North polarity And suggest which one of these magnets have more magnetic strength wise on the bigger portion 50*50(in this case center magnetic strength will be less). Correct me if I'm wrong
Why is the test not simpler, using an everyday Kg weight? By having a pre weighed container with a steel top being held up by the same outer perimeter as the suspended testing magnet. To the container add further weights until the suspended container separates from the magnet. From there the suspended weight can be calculated and that is the magnet strength. To go further if the top of the container is a magnet of the same value will this hold twice the weight?
This is easily done with a simple formula, pulling either two magnets apart or a magnet off a steel plate (or sometimes a magnet between 2 steel plates). The most convenient is the magnet from single steel plate. Just measure with a digital force gauge and apply formula or use a chart. Much easier than what you're doing. No need to mess with gauss at all. Edit: nvm. You're using a magnet far too powerful to use this method. My method is for neodymium magnets under 1.5" on the longest side. Above that it requires more than muscle power to pull the magnets off.
Can you please provide me a calculation sheet for measuring flux density of a circular arc magnet. The arc has some thickness and its ends are aligned along radii of the same circular arc
*Brainiac75, i have to confess something to you. a key reason i subbed is that i hope you will slip up one day and say **_"i love GOLD"_** on camera and i want to be there to catch it when you do ... but i can't be the only one. maybe you can make a goodie at 620K subs and say the line? :-)*
@@brainiac75 i bought sum circular magnet recently with the holes in the middle to try sum experiment with them.they said they were n52 but i always wondered how can we check em.been a long time fan👍
In case nobody mentioned this before: I think you are a bit harsh on your own abilities. I think your method is roughly working. But you are also making things more difficult for you in that you focus on absolute values. When you compare magnests' relative to each other selecting one known reference sample, then the erelative differences are much more reliable than the absolutes since you can statistically eliminate random errors whic is easier for relative measurements than absolute ones. The only requirement is that grades for magnets vary linearly. Just thought it might help a bit.
How do I turn a gauss measurement into a grade measurement Also is gauss just an electromagnet measurement unit or a magnet unit of measurement as well
Rather than finding exact center of the magnet, could you not just move the probe around the magnet until it registers the strongest reading on the meter? Wouldn't that actually be a more accurate assessment of the magnets true strength? I suppose theoretically, the field should be strongest at dead center, but idk, that's why I'm asking...
The formulas are only for the exact center of the magnet. All the shown magnets are much stronger at the edges, but that goes for all grades. The grade calculation in the spreadsheet only works for the center, so I only focused on that in this video to determine the grade - not how strong the strongest point of the magnet is - or how large a pull force the total magnet has. Thanks for watching!
Weight connections with gauss and area ? If we compressed Two strongest magnet by hydraulic jack against each other and place a coil so what happened ? Use strongest magnet and hydraulic jack for making electricity
There are many things in science that at least I feel I have a notion of. I don't understand them completely, but I think I get the concept (e.g. how DNA is translated to proteins, why an apple falls down to earth, why my car is moving with the energy of small explosions, and that lasers make some very accurate beams of light) but with magnetism it is still like magic. I can apply the laws that I learned in physics, but my brain doesn't get through. Where does the magnetic field come from? Whats special about iron? Why doesn't it wear off (or does it?)? How can the force have an impact over some distance (And how fast is it? Light speed?)? And how big is the magnetic field and why? Maybe this is a suggestion for a new video: magnetism for dummies.
I bought a 30mm x 50mn n52 disk magnet and had the same feeling come to find out it was a n35 being sold as a n52 AliExpress has a lot of people selling fake n52 magnets
I would definitely leave a review on the site where the phony magnet was bought. It's still a good magnet, but the false advertising should be brought to light.
Ebay doesn't really work like that. If you start leaving bad seller reviews, the sellers start leaving bad buyer reviews and then nobody wants to sell to you. Anybody who buys on Ebay should expect false advertising and adjust accordingly. American sellers are more reliable but even then, if you are easily offended, Ebay is not for you.
The limited edition magnet was a 15 year anniversary celebration for supermagnete. But yes, magnets do lose magnetism over the years. Neodymium magnets are however very resilient and are said to last for centuries. But they will eventually lose their magnetism - for example due to natural background radiation (neodymium magnets don't do well with radioactivity). Thanks for watching!
You make learning very enjoyable good job.. Question? Say you have a sphere the inner side being all north and you put a south int he center or vise versa do you know what would happen? I also had a strange kinda occurrence I have a TV speaker magnet I broke the back plate off so the center part could pass through either way I forcefully was able to center it without touching any of the side top or bottom now that little center price is almost stuck very strong to pull it out either way. What happened thank you for your videos ☺️
Well, ring and spheres are interesting. I don't think you'd have a 'questionable' big magnets (think the shady 'N52') with that shape, but then again that could make the job easier. Speaking of, are reputable N45-48 of the same size tend to be more expensive than that shady 'N52'? Engaging stuff as usual, though. Love the 666 sneak joke, I'm a bit weaker to arithmancy jokes than I think I am XD
Yep, I will attempt to measure the grade of ring and sphere magnets too. I just realized from punching some random numbers in, that sphere magnets are very sensitive to sensor depth. The +/- 0.3 mm variation in the probe will make quite a difference, so I will have to be extra careful. But it could be fun to try. Maybe I can even determine the actual sensor depth in my probe from this, if I test a lot of sphere magnets :) Thanks for watching!
I bought the 'fake' magnet many years ago and struggle to remember the exact price (and the seller is long gone). I just remember I bought it because it was much cheaper than the similar one from magnetportal. Current price on the magnetportal N52 70x20 mm is €61, so the other may have been in the ballpark of €40 back then.
The formulas used in the spreadsheet are for the center of the magnet only. Mapping the entire poll surface, edges etc. requires sophisticated programs. Not just a spreadsheet. I may give the free program FEMM a try in the future. But yes, the edges typically have the highest flux, but they are difficult to measure consistently. Even the tiniest angle or position change can mean a big difference in gauss reading. It is much easier on the center (though tiny angle or position changes also matter here - just not as much).Thanks for watching and asking a clarifying question, that I should have included in the video ;)
Hey there. I just recently sold some gold and silver bars to a dealer and he checked whether they were real by running a powerful magnet over them. Gold and silver are NOT magnetic. But he let me try it and there definitely was some _resistance_ when I ran the magnet over the big silver bar. I couldn't believe it! What caused this do you think?
If you got paid less for the silver because of this then you were definitely scammed. For more info on this effect you can look up experiments where a magnet is dropped through a copper pipe, copper also not being ferromagnetic.
Hey, it is caused by eddy currents. You are feeling the magnetic field of currents being induced in the gold/silver (no electricity without a magnetic field). The better electrical conductor, the more eddy currents and resistance when dragging the magnet over it. Gold and silver are both excellent electrical conductors. I have an old video experimenting with it in copper and aluminium which are also good electrical conductors but not magnetic: ua-cam.com/video/QJyWaliROPo/v-deo.html The effect is even stronger, when freezing the copper: ua-cam.com/video/nz9N_RlFloM/v-deo.html
@@-Devy- I didn't get paid less. He was just making absolute sure that what I was giving him was the real deal. There was significant resistance, even though the magnet had no attraction to the metal itself. Was a cool effect. I never would have guessed this was real.
I hope you were able to get an N95 neodymium-iron-boron magnet! Oh, wait... Magnet grades don't go up to N95; that grade is only for face masks. Anyway, I hope you were able to get one and stay safe from COVID-19!
Download the excel version from the link in the description (www.supermagnete.de/eng/faq/How-do-you-calculate-the-magnetic-flux-density). Then open that file in Google Sheets. It imports the excel file just fine. Thanks for watching!
Hi Brian, I am late to the party but am trying to grade some magnets and have run into an issue. I have a very strong magnet sold as N52 - and which certainly has a very strong pull force - but which has a surface reading of 452 mT for a 60x35x35mm size, measured by a relatively cheap gaussmeter. That would seem to equate with an N35/N38 per the spreadsheet you link to here, but that seems incorrect given the observable size of the magnetic field (1mT @ 10.5" from the surface) and the effort required to separate it from steel. Do you have any idea why the measurement may be so low for what is a very strong magnet that compares in pull force to other magnets with much higher surface gauss?
@@unknown_10453 Ok, if you say. I like a spreadsheet that is fully featured. Google sheet is nowhere near fully featured and not any better looking that OpenOffice.
Is there any other influential mathematician/physicist who got a shorter stick than Tesla when it comes to units/formulae named after them? All he gets is a simple factor of another unit.
I tried grading a magnet, but it never submitted any coursework.
Then that’s a 0 for effort.
take ur up-vote and get out
I think the joke was quite polarizing
0/10 (F-); It didn't stick to the topic.
@@Grocel512 haha *slap* no
8:58 i'm with you all the way. Too many scammers these days.
Yep, buyers beware. I was not that surprised from the result, but you always have that hope, that the other sellers just charge too much... But with grade N52 there are no cheap solutions in the manufacturing :( Thanks for watching!
The sellers are just crazy. Lasers are sold overpowered and dangerous without any safety, as we know from your previous video, and things like flashlights and as i see even magnets are underpowered...
@@brainiac75 If you complain about this as a cheap copy to ebay or paypal you'll get your money back and can keep the magnet.
Thank you for your demonstrating how you grade the power of these magnets.
You are welcome. This is my first attempt at determining the grade of magnets. I may refine or polish the method in the future. Especially based on feedback from viewers who most likely will have some input :)
@@brainiac75 any way to strengthen a neodymium magnet?
@@vivimannequin Own a foundry, and remelt it.
You're better off selling your old one and buying a higher quality one if that is what you seek.
Channels like yours are exactly what keep me invested in UA-cam.
Please keep it up!
"I'm a lazy boy" Only Braniac75 would say that. BTW I love your vids!
Thanks, Ben :D I actually didn't realize the tesla/gauss settings until I watched the footage. Didn't bother to re-shoot the measurements...
Put some thermal paste on your magnets
A lot of people say that lol
This is my last comment regarding this I swear: Here is how you make a ferrolens: find 2 panes of FLAT glass (I eventually added a third layer of glass). They need to be really flat or you will end up with bubbles. Optic flats are best, but pricey. Then mix 1:1 ferrofluid and WD40. Shake up the mixture and then let it sit to get bubbles out. Then add this mixture ( you dont need much) to one pane of glass. Then slowly lower the second pane on top of the first one. This makes a super thin layer of the mix. Now you just need to mount the panes of glass in a black lined box (i used a shoebox) and light from below with multicolored or white LEDs. Now get a magnet and see the cool instintaneous changes. These arent the field lines, but some other representation of the magnetic flux (i didnt look into it too deep, gets technical fast). Checkout my videos on it. There are one or two how to builds on UA-cam as well which show you how to make one. Hope you at least google it. Thanks again!
Thanks for the details. I like your enthusiasm :D
So....Did you check it out? Its right up your alley. Come on..Love your content by the way. Using my radiascan to analyze my uranium glassware. I told Smart Elements that I was refered by you. Im a fluorescent mineral collector, so i appreciated the doped beads that glowed. Checkout tenebrescence if you want to see a cool trick with some special minerals (i have a video on that too if you dig around). You need to upgrade your UV sources! That germicidal lamp just wont do, you need a good shortwave ultraviolet lamp. They are pricey, but well worth it. I'm going off on a tangent though, make that ferrolens!
Just looked at your video of the ferrolens. I'm going to have to make one of those now.
cool effect, looks like field-lines to me
@@AwsomeVids83 what video? I don't see one up
That evil laugh At 5:06 Made my day
Glad I can help, Jonas :) Most likely not my last evil laugh, hehehe.
It was so random ehhehehehehrrr xD
I'm glad to see that you're doing well during these dark times! Your videos are always interesting and teach me something new whenever I watch one. Stay safe out there and best of wishes for your experiments in the future!
Denmark is a safe place in so many ways, so I'm fine, thank you. More videos too come!
"Ebay, the trash can of China." Big Clive.
Hehe. In many cases true, but I do like eBay. You can get so many things there, that are impossible to get anywhere else. Good for a guy with alternative interests like me x) But buyers beware. Safety is rarely a concern in the cheap products and if it is too cheap to be true, then... Thanks for watching!
eBay May well be a trash can but if you take all ratings with a pinch of salt then you can score some good deals.
If it says 8amp chances are 2amp is fine.. and you can buy stuff cheaper than you could buy the parts or any of the individual parts..
You can get a pwm 8amp rated dimmer for £1.32 delivered. You can’t buy the box for that or the control knob or the components lol and it’s not 8amp that’s for sure but for controlling led lights it works ok...
Just don’t buy stuff you may need to rely on...
Still huge value, though. Two trash pieces exceed the specs of a single premium piece and are only a tenth of the price!
I do like ebay too. I live in a small country called Denmark where it is often difficult to get specialized goods. Here eBay is great.
Pretty sure that’s “wish”.
Great video as always! Yes, I would like to see you grade the ring and sphere magnets with your method.
Quarantine's keeping us in, and we might as well keep ourselves entertained and educated with videos like these!
Thanks, Sir. I am not in quarantine here in Denmark, so I don't have more time to make videos than usual. But more videos coming every month! I will attempt ring and sphere magnets too. The sphere magnets are very sensitive to even small changes in sensor distance etc. so I need to be even more careful...
7:18 I just use a measuring compass and or calipers. you just set the radius close enough by eye (you can dial it down even more after) then swipe from at least 4 opposite sides of the circle. very simple and easy, the 4 curved marks will always meet up at the center. you really only need 3 marks, but 4 is easier and extremely accurate when finding opposite sides by eye. maybe there is a easier way though, but after finding the center in only couple seconds and drilling it, I get +/- 0.02mm run out in the lathe.
Hey Brian! I have learned countless things from you over the years that I cherish now. Love the quality > quantity content! Wish you luck!
Thanks. Glad you like it, PRISK. More monthly quality uploads to come :D
Everybody: Wow, cool magnets and technique!
Me: WTF, that teslameter is running Android!
Tak for fedt video :D
Tak, James! Well spotted. A detail not everyone would have noticed :)
Is it Android or does it just have a frontend built with Google-s material library.
If you had a known thickness perspex that you place between the probe and the magnet under test, then small variations of coatings etc. will be less of an issue. Love the insight you provide on magnetism.
Not a bad idea. I will do further testing - including how accurate the formulas are at a farther distance over the center. This was the first test - I may improve the method on feedback like yours - thanks!
We faced a similar problem with neodymium magnets. We produce ebike and e-scooter motors and therefore these motors have strong magnets inside to produce large torque.
In fact some magnets we tried were about 1.5x short of their claimed field strength (magnets were labeled as N38) so the motors were badly lacking torque and overheated. Then we chose another magnet supplier to buy similar grade magnets and then motors were able to match expected characteristics.
I am not surprised. It is hard to determine the grade precisely without good equipment, so many manufacturers may be tempted to exaggerate the grade -expecting customers not be able to test it. Thanks for sharing a real life problem with low grades. Glad you found a good manufacturer!
Sonofagun, this is the kind of stuff to watch each day, every day, to actually learn something, instead of the usual drivel found these days on UA-cam. Good job, Brainiac! Have been a strong subscriber for many years now and will continue to do so! I wish I was able to support you through your Patreon, but I live in a goddamn ridiculous country that has not yet developed any such ways to make international payments/purchases..... Until that day comes, I'll always be a member of your insanely awesome club! Cheers!
Hi Brainiac! I like your vids, subtitles help me to learn English and some physics. From Russia with love! ❤
You always do such a a great job on your videos. Thank you for making these!
Thank you very much! I spend a lot of time on these videos. Days for the voiceover alone... More to come!
Honestly your videos are amazingly satisfying.
HOLY SHIT
This brings be back to 2007 when I found your channel
Here I am again, 14 years later
Glad to see you again! Best wishes to you and the ones who sorround you :D
Thanks, same to you. Though I haven't been gone for longer than usual. Did you miss one of my videos: ua-cam.com/users/brainiac75videos
Otherwise you know the drill: Subscribe and click the bell, all notifications ;) Thanks for watching!
@@brainiac75 Thank you! Yes I'm already subscribed :)
"Imagine if had serial number 666 too and combined them to a single 2 inch cube magnet"
**Puts down magnets 420 and 69**
**runs past and steals recently abandoned magnets 69 and 420, adding them to the recently procured magnets 13 and 666**
*I AM NOW KING!*
Very nice. This video feels so much like how the amateur laser hobby was in the early 2000's (ie, 2003) when we basically had no means of testing the optical output (watts) of a laser diode or module. Or the optical output (lumens) of LED flashlights. It's nice for a hobby to finally acquire access to testing the outrageous claims made on eBay.
Did you make your ferrolens yet? Lol. I really hope you look into it.
I allways enjoy your videos mate ! keep doing what you doing and since i am driving through Danemark in a week i will buy a magnet in your honor, happy summer and stay healthy!!!
Wow, I was impressed that the cheap eBay alternative was so close to being what it was said to be personally! I thought it was going to be much worse!
Btw. Your videos are so professional you deserve more attention
Thanks. I am an amateur but try to make quality videos. Quality over quantity!
I have been waiting for a video like this, and you have field ones? Awww yeaaah..
Please, please make a ferrolens! Its a gadget you can make at home using two panes of glass with a super thin layer of ferrofluid mixed at a 1:1 ratio with WD40. In the presence of a magnetic field the ferrofluid creates tiny thin lines which act like a diffraction grating. This creates a cool 3D holographic effect when lit by leds from below. I made one and it is so awesome. I have some videos about it on my channel. Just go back a couple months. But please make one. It is so worth it. It is sold commercially as Ferrocell by its inventor, but is easily made at home with common items (except the ferrofluid, but you must have some of that on you). Love your videos btw. I ended up buying a radiascan 701 and the glass bead element collection too. So cool.
Hi Jared. Ferrolenses do look good. Visualizing the beauty of a magnetic field, so I might attempt it. I just know messing with ferrofluid is always... messy. Glad you like my videos and end up experimenting yourself :)
@@brainiac75 I love your videos! I hope you brave the mess (I'm not going to lie, it can easily get messy). I have a bunch of random videos on my channel(that no one is watching), but if you find the one where I put repelling magnets on the ferrolens. It makes this awesome vortex/blackhole looking thing in the middle of them. Also checkout the video with the ring magnet, they look amazing on the ferrolens, making this spirograph looking pattern in the hole of the magnet. I bought a ring magnet specifically for this. I am glad that you checked it out and were kind enough to take the time to reply to my comments. While I have you, have you checked out the RGB laser pointers they have out now? They have actually been out for a couple years now, but i picked up one from Sanwu and another cheaper one from another website. They are really expensive, but you can mix the red, green, and blue(as you know) to make most the colors including white. I know you like lasers, and the one from Sanwu comes studded in tritium vials! They have one special one made of damascus steel(that is ridiculously priced) but comes with 98 tritium vials studding it! My radiascan goes crazy with my laser which has a dozen of them on it. Anyway, this reply is going on too long. Thanks
Moral of the story: You get what you pay for.
That is true for so many scenarios. There's no cheap shortcut to N52 - it is an expensive process to get right. Thanks for watching!
Almost always true, but there are exceptions. The cheapest highest quality bearing is currently, and has been for a long time, the one that is used in skateboards (608ZZ). Because that one bearing type is used so much globally (They are mass produced in greater number than any other bearing type) the price point has dropped to be much much lower than any other bearing of similar size and the quality has actually gone up over time.
People who design new products look for existing high quality parts in current mass produced items so that they can reduce costs and use higher quality parts in their product by piggybacking on someone else's design who is buying so much of that part that the price point is lowered as production is ramped up to meet demand.
Also some sellers will intentionally overprice their item to make it appear higher quality.
@@itsevilbert Yeah maybe, but science and engineering equipment (such as these magnets) is not exactly mass produced, because there is not that much demand for it. That stuff have to be higher quality as well, because low quality (or outright counterfeited) stuff is useless in those fields. The clients who needs such equipment are usually more solvent than many private individuals.
They don't need to do that ugly busyness with some random untrusted/unknown 2nd hand crap. They either know what and from whom they buy or they just don't buy. If professional want to save money they buy 2nd hand from other trusted professionals. It has to be a lot cheaper though, because they also account the expensive value of labor for the extended product validation/checking/refund process the into the transaction...
@@userPrehistoricman Yeah, these are called Intel or Apple. Companies for professional Science/Engineering equipment however are probably a bit more trustworthy, because they know that their clients aren't stupid. Reputation is key in these fields, so they think twice about fucking their clients over.
You should also measure the leading edge of each magnet; as this is the area which has the greatest concentration of magnetic lines of force. That is to say that when you look at either face associated with the north or south pole and move from the center of the face to the edge where either the north and south meet one of the side faces; that edge has the greatest flux density. I would suppose that you might actually find that a magnet which seems to have a very low gauss rating when measured at the center of the pole has a noticeable higher rating at the edge, and you may even come up with different results when comparing different magnets in this way. The north/south poles as well as the so called bloch wall, are almost like termination points of the lines of force composing the field, and if the strength of field is determined by density of lines of force; then you are by definition measuring the strength of said magnets at their points of least concentration of lines of force.
You almost surpassed 100million views, keep on going!
I am not stopping any time soon! Thanks for being part of the first 100 million views ;)
Would like to see your calculations if you use a greater distance, say 10 mm, rather than "contact" distance between the surface and the magnetometer probe. Would it give you smaller uncertainty in the distance measurement? Love your experiments!
Btw, I keep reviewing your series on para/diamagnetism of elements, especially those noble ones. Have you thought of testing metals as colloidal suspensions? Some can be easily made by shorting and sparking electrodes made of the metals in/under water. How would the (nano)particles react to a strong magnet?
I just want to say I have truly enjoyed your videos. Unfortunately I am unable to Patreon due to fiscal problems but Thank You for your videos.
Thank you for illustrating us
LibreOffice is free and open source and LibreOffice Calc does a really good job. It's good to have it around when you don't want to go online for a mere simple spreadsheet.
Thanks for sharing. The shown spreadsheet is available both as an excel and open office document. I just downloaded the Excel version and opened it in Google Sheets. Works fine for me :)
Thanks brainiac! I'm still a kid but i still understand at least most of it!
Glad you like it! If you know and understand it all, you have nothing to learn. That's boring ;) Keep watching, and you will soon understand it all.
THAT EVIL GIGGLE! This is why I like this channel. You've kept your soul and heart intact and haven't sold out to be a souless freak like most youtubers nowadays.
Thanks :) Sometimes the passion just takes total control over me :D Thanks for the watch and comment!
Excellent video as usual!
Love your videos bro!
Love from 🇧🇩 Bangladesh 🇧🇩
Hey Brain, I just have a doubt can you clarify? What would be the Gauss value if the polarity was divided between 50*50 /2 like Half South polarity and half North polarity And suggest which one of these magnets have more magnetic strength wise on the bigger portion 50*50(in this case center magnetic strength will be less). Correct me if I'm wrong
always look forward to you next video ,thanks
Glad you like it, sean. More to come!
Why is the test not simpler, using an everyday Kg weight? By having a pre weighed container with a steel top being held up by the same outer perimeter as the suspended testing magnet. To the container add further weights until the suspended container separates from the magnet. From there the suspended weight can be calculated and that is the magnet strength.
To go further if the top of the container is a magnet of the same value will this hold twice the weight?
Maybe the accuracy would be better, if you would use longer measuring distance. The error bar is percentagewise much greater in 0.35mm, than in 10mm.
This is easily done with a simple formula, pulling either two magnets apart or a magnet off a steel plate (or sometimes a magnet between 2 steel plates). The most convenient is the magnet from single steel plate. Just measure with a digital force gauge and apply formula or use a chart. Much easier than what you're doing. No need to mess with gauss at all. Edit: nvm. You're using a magnet far too powerful to use this method. My method is for neodymium magnets under 1.5" on the longest side. Above that it requires more than muscle power to pull the magnets off.
Can you please provide me a calculation sheet for measuring flux density of a circular arc magnet. The arc has some thickness and its ends are aligned along radii of the same circular arc
I am curious what else you use these magnets you test ? Do you go junk fishing in the nearest body of water or do you collect them ?
*Brainiac75, i have to confess something to you. a key reason i subbed is that i hope you will slip up one day and say **_"i love GOLD"_** on camera and i want to be there to catch it when you do ... but i can't be the only one. maybe you can make a goodie at 620K subs and say the line? :-)*
I wanted to know about grades u didnt let me down..always learning something..good video
Glad to hear Dj. This is my first attempt at measuring grades. I may improve in the future :)
@@brainiac75 i bought sum circular magnet recently with the holes in the middle to try sum experiment with them.they said they were n52 but i always wondered how can we check em.been a long time fan👍
Great video brother 👍👍
Thanks. And yet again thanks for the feedback on Twitter ;)
In case nobody mentioned this before: I think you are a bit harsh on your own abilities. I think your method is roughly working. But you are also making things more difficult for you in that you focus on absolute values. When you compare magnests' relative to each other selecting one known reference sample, then the erelative differences are much more reliable than the absolutes since you can statistically eliminate random errors whic is easier for relative measurements than absolute ones. The only requirement is that grades for magnets vary linearly.
Just thought it might help a bit.
How do I turn a gauss measurement into a grade measurement
Also is gauss just an electromagnet measurement unit or a magnet unit of measurement as well
Thanks, learned something today.
Can you make a Searl Effect Generator and demonstrate how to generate free energy? Such a big audience may be interested in knowing this is possible.
That would be pretty silly, since there is no such thing.
Rather than finding exact center of the magnet, could you not just move the probe around the magnet until it registers the strongest reading on the meter? Wouldn't that actually be a more accurate assessment of the magnets true strength? I suppose theoretically, the field should be strongest at dead center, but idk, that's why I'm asking...
The formulas are only for the exact center of the magnet. All the shown magnets are much stronger at the edges, but that goes for all grades. The grade calculation in the spreadsheet only works for the center, so I only focused on that in this video to determine the grade - not how strong the strongest point of the magnet is - or how large a pull force the total magnet has. Thanks for watching!
@@brainiac75 ...I see, thank you! Very informative, and it's my pleasure to watch your videos! 👍
Thank you! Needed this.
love your videos
Thanks :) More to come.
When do you make or dedicated a whole episode to the use or something with fire ??
I never knew you Could measure the magnet. I'm surprised I've learned Something new today
The Spreadsheet for calculating flux doesn't show available for download.
Weight connections with gauss and area ?
If we compressed Two strongest magnet by hydraulic jack against each other and place a coil so what happened ?
Use strongest magnet and hydraulic jack for making electricity
There are many things in science that at least I feel I have a notion of. I don't understand them completely, but I think I get the concept (e.g. how DNA is translated to proteins, why an apple falls down to earth, why my car is moving with the energy of small explosions, and that lasers make some very accurate beams of light) but with magnetism it is still like magic. I can apply the laws that I learned in physics, but my brain doesn't get through. Where does the magnetic field come from? Whats special about iron? Why doesn't it wear off (or does it?)? How can the force have an impact over some distance (And how fast is it? Light speed?)? And how big is the magnetic field and why?
Maybe this is a suggestion for a new video: magnetism for dummies.
I bought a 30mm x 50mn n52 disk magnet and had the same feeling come to find out it was a n35 being sold as a n52 AliExpress has a lot of people selling fake n52 magnets
I would definitely leave a review on the site where the phony magnet was bought. It's still a good magnet, but the false advertising should be brought to light.
Too late... I bought the magnet several years ago and can't find the seller. Thanks for watching!
Ebay doesn't really work like that. If you start leaving bad seller reviews, the sellers start leaving bad buyer reviews and then nobody wants to sell to you. Anybody who buys on Ebay should expect false advertising and adjust accordingly. American sellers are more reliable but even then, if you are easily offended, Ebay is not for you.
Great video!
Thanks :) More to come.
Thanks for the math lesson! You have such a magnetic personality!
Hehe, at least I am attractive in one way then x) Thanks for watching!
Interesting how eBay magnets are always labelled N52, because Temu magnets are all labeled N35 which probably means they're actually N30
I’m getting flashbacks of LA beast videos
How about attracting max weight then head up the magnet to 80C/100C/120C/150C and measure if magnetism drops?
hwy brian where did you get that orange cube magnet ?
What does the 15years mean on the box of that magnet? Do magnets loose their magnetisation over time?
The limited edition magnet was a 15 year anniversary celebration for supermagnete. But yes, magnets do lose magnetism over the years. Neodymium magnets are however very resilient and are said to last for centuries. But they will eventually lose their magnetism - for example due to natural background radiation (neodymium magnets don't do well with radioactivity). Thanks for watching!
Do you have a link to that spreadsheet?
I'm intrigued to understand the magnetic fields in and around a spherical magnet.
I thought a magnet's force was measured by the number of cats it takes to try to push it off a countertop?
N55 and N58 are actually the highest commercially available grades. They're not big though.
7:23 is that a crack across the surface form right to left? maybe a manufacturing cast off?
You make learning very enjoyable good job.. Question? Say you have a sphere the inner side being all north and you put a south int he center or vise versa do you know what would happen? I also had a strange kinda occurrence I have a TV speaker magnet I broke the back plate off so the center part could pass through either way I forcefully was able to center it without touching any of the side top or bottom now that little center price is almost stuck very strong to pull it out either way. What happened thank you for your videos ☺️
How do you store all the magnets?
Well, ring and spheres are interesting. I don't think you'd have a 'questionable' big magnets (think the shady 'N52') with that shape, but then again that could make the job easier. Speaking of, are reputable N45-48 of the same size tend to be more expensive than that shady 'N52'?
Engaging stuff as usual, though. Love the 666 sneak joke, I'm a bit weaker to arithmancy jokes than I think I am XD
Yep, I will attempt to measure the grade of ring and sphere magnets too. I just realized from punching some random numbers in, that sphere magnets are very sensitive to sensor depth. The +/- 0.3 mm variation in the probe will make quite a difference, so I will have to be extra careful. But it could be fun to try. Maybe I can even determine the actual sensor depth in my probe from this, if I test a lot of sphere magnets :) Thanks for watching!
Can someone tell me what are the uses for those magnets?
The ring magnet will be hell to measure
What’s the price of the both magnets (eBay, magnetportal)
I bought the 'fake' magnet many years ago and struggle to remember the exact price (and the seller is long gone). I just remember I bought it because it was much cheaper than the similar one from magnetportal. Current price on the magnetportal N52 70x20 mm is €61, so the other may have been in the ballpark of €40 back then.
Brainiac75 ,do you think that a 40mm x 20mm (disc) neodymium magnet is nice for beginners?
Why do you only measure the flux at the center of the magnet? Is this standard? Won’t you get higher flux around the edge?
The formulas used in the spreadsheet are for the center of the magnet only. Mapping the entire poll surface, edges etc. requires sophisticated programs. Not just a spreadsheet. I may give the free program FEMM a try in the future.
But yes, the edges typically have the highest flux, but they are difficult to measure consistently. Even the tiniest angle or position change can mean a big difference in gauss reading. It is much easier on the center (though tiny angle or position changes also matter here - just not as much).Thanks for watching and asking a clarifying question, that I should have included in the video ;)
Brainiac75 thanks for the awesome videos always!
Your videos are awesome :)
Thanks, Jiří! More to come :)
Great video
Hey there. I just recently sold some gold and silver bars to a dealer and he checked whether they were real by running a powerful magnet over them.
Gold and silver are NOT magnetic. But he let me try it and there definitely was some _resistance_ when I ran the magnet over the big silver bar. I couldn't believe it!
What caused this do you think?
If you got paid less for the silver because of this then you were definitely scammed. For more info on this effect you can look up experiments where a magnet is dropped through a copper pipe, copper also not being ferromagnetic.
Hey, it is caused by eddy currents. You are feeling the magnetic field of currents being induced in the gold/silver (no electricity without a magnetic field). The better electrical conductor, the more eddy currents and resistance when dragging the magnet over it. Gold and silver are both excellent electrical conductors. I have an old video experimenting with it in copper and aluminium which are also good electrical conductors but not magnetic: ua-cam.com/video/QJyWaliROPo/v-deo.html
The effect is even stronger, when freezing the copper: ua-cam.com/video/nz9N_RlFloM/v-deo.html
@@-Devy- I didn't get paid less. He was just making absolute sure that what I was giving him was the real deal. There was significant resistance, even though the magnet had no attraction to the metal itself. Was a cool effect. I never would have guessed this was real.
Aren’t the edges of the pole faces the strongest areas of any magnet?
How can I not click like with your proposition?
Would a iron ball attached to a scale be more accurate?
I hope you were able to get an N95 neodymium-iron-boron magnet! Oh, wait... Magnet grades don't go up to N95; that grade is only for face masks. Anyway, I hope you were able to get one and stay safe from COVID-19!
I'd love to see you confronting the seller on eBay
4:54 Ah, so that's how you summon Satan!
I couldn’t find the google spreadsheet link?
Download the excel version from the link in the description (www.supermagnete.de/eng/faq/How-do-you-calculate-the-magnetic-flux-density). Then open that file in Google Sheets. It imports the excel file just fine. Thanks for watching!
What happens if you put a small sphere magnet in the middle of a ring magnet?
It would align to the magnetic field of the ring magnet and fly to the inner edge (hole edge) of the ring magnet. Thanks for watching!
@2m50s: Uncalibrated table. Rewind back to 1m30s and it's calibrated. :-)
So easy to time-travel in editing :P Thanks for watching!
Is this method good enough to get a refund from ebay and aliexpress who falsely label their magnets as N52 ?
Hi Brian, I am late to the party but am trying to grade some magnets and have run into an issue. I have a very strong magnet sold as N52 - and which certainly has a very strong pull force - but which has a surface reading of 452 mT for a 60x35x35mm size, measured by a relatively cheap gaussmeter. That would seem to equate with an N35/N38 per the spreadsheet you link to here, but that seems incorrect given the observable size of the magnetic field (1mT @ 10.5" from the surface) and the effort required to separate it from steel. Do you have any idea why the measurement may be so low for what is a very strong magnet that compares in pull force to other magnets with much higher surface gauss?
Install OpenOffice, it's spreadsheet is much nicer than google sheets and free. It has all the feature of Excel.
It's not nicer imo, in fact it's pretty ugly comparitively, but it is free and not online.
@@unknown_10453 Ok, if you say. I like a spreadsheet that is fully featured. Google sheet is nowhere near fully featured and not any better looking that OpenOffice.
@@synthesizer8026 I said imo, you have your opinion and I have mine. All in all excel is the best, but imo Google sheets is right after it.
@@unknown_10453 That is why I said if you say. I wasn't disputing. I just gave my opinion. And yes as far as features go nothing beats Excel.
Please make a video on 40x40x20mm neodymium magnet
Is there any other influential mathematician/physicist who got a shorter stick than Tesla when it comes to units/formulae named after them? All he gets is a simple factor of another unit.