Monolith Magnets | Twice the Power?

Hi! And welcome to my story about the Monolith magnets. Usually there's not much story to tell about a magnet but this one is unusual. I will also test the three grades of this magnet against each other and finally I'll attempt to put two of these together. This is by far the biggest magnets I have ever attempted to pair up. Like 2½ times larger than my previous record size so I may be in for a challenge. If I and the magnets survive the pairing I will test how much better the double magnet performs in the same tests. Will it surprise us? In this video we'll encounter strong magnetic fields and a bad risk of getting pinched. "Once-upon-a-time - back in 2010 - a big, black, tempting magnet was born." "The magnet was named the Monolith and it wasn't like the other magnets." "It was a limited edition and very big for being a black magnet." "It was even delivered in a crude coffin and had a strange tattoo." "Its size and form factor were.... peculiar." "And it could handle more heat than its friends." "Why was this magnet so different?" A fairytale it is not... [record scratch] Actually this magnet just wasn't supposed to be for sale on the consumer market. It was manufactured for a very specific purpose: Being part of an electric generator. I have asked the seller for more details but it's a trade secret.... All I know is: It was a large producer of electric generators based in Germany that introduced a new model design so they were left with an overstock of several thousands of these magnets they couldn't use anymore. They sold the remaining stock to webshops specializing in selling neodymium magnets and suddenly the Monolith magnet was available in a limited edition to you and me. This explains the peculiar design of the magnet. The very precise and unusual measurements are simply because the generators weren't built around a standard stock magnet. They designed the generator first and ordered custom magnets fitting the specific design. The industrial packaging with some rough plywood thrown together also makes more sense in this context. Consumer magnets don't usually come with pointy nails near them. And they don't have a handwritten N on their north poles like the industrial Monolith. The black epoxy coating isn't rare on smaller neodymium magnets but it is for a magnet this large. The epoxy coating is more weatherproof than the standard nickel coating on most neodymium magnets. So a good choice for a generator that may have to be outside in all kinds of weather. The heritage of the Monolith is revealed by its grade as well. The first Monolith sold from 2012 is grade N38SH. More info about grades in another of my videos but the interesting bit in this case is the SH ending. It indicates that this magnet can withstand temperatures up to 150° Celsius without losing any of its magnetic force. Normal graded neodymium magnets start losing magnetic force over 80°C but not the Monolith. This will stay strong even inside a generator working hard directly in the sun on a hot day. Later, the Monolith 2 was released from the same limited stock and this is grade N45SH. It is a stronger magnet and still able to endure 150°C. The two limited-stock Monoliths sold well. I bought three of them myself for around €100 each. So popular in fact that Supermagnete decided to make their own version of it as part of their permanent assortment. The Monolith 3. This is exactly the same size as the earlier Monoliths, epoxy-coated and in grade N45. Basically, the Monolith 3 is a Monolith 2 downgraded to withstand a more normal 80°C which makes sense. Magnets graded for higher temperatures are more expensive to make and for most of us 80°C is more than enough. Mine haven't been above 30°-ish. Supermagnete donated this third version to me which is nice since I can now test all three versions against each other. First test is the inversed compass. From how far away will the magnet spin a compass all the way around? In other words: At what distance is the magnet's magnetic field still stronger than the Earth's magnetic field? With the center of the compass needle 101 cm from the center of the magnet the first Monolith passes since the needle turns upside down. The Earth's southpole is straight down in the picture. But at 102 cm - one centimeter more - it will not turn the needle upside down. I've got two Monolith 1's so let's test the second Monolith 1 too... This one passes at 100 centimeters but fails at 101. So a tiny bit weaker even though of the same size and grade. This is because grade N38 means a strength between 36 and 38 megagauss-oersteds. It is a range for the material used in the magnet. Not an exact measurement of each magnet. How about the stronger Monolith 2 at grade N45SH? Well, it does pass at a farther distance - 104 cm but fails at 105. Not a big improvement. It's exactly the same story with the Monolith 3. Pass at 104 cm, fail at 105. It seems like grade doesn't matter much at a far distance. Size must be more important since small magnets definitely would not work in this test at a meter or more. Let's try another test where the magnet has to work at a distance: The Saw Bend test. In this I'll measure at what distance the magnet will bend the saw blade 5 cm away from its resting position. First up is the weakest from the compass test. An original Monolith Mk. 1 in grade N38SH. This one passes the test at a distance of 13.5 cm. The second Monolith Mk. 1 is a tiny bit better and passes at 13.6 cm. Let's step it up and test the Monolith Mk. 2 in grade N45SH. This is not much better, 13.8 cm. And not surprisingly the Mk. 3 scores an equally disappointing 13.8 cm. So the conclusion of the saw bend test is very similar to the compass test: When working with the magnet at a distance grade doesn't seem to make much of a difference. Size must be the most important factor since the higher grade barely makes a difference with similarly sized magnets. We need to try a completely different test where the magnets have to work on a small object at point-blank range: The Paperclip Test In this test I simply put a paperclip right on the surface of the magnet and test how much pull force it takes to remove the paper clip from the magnet again. Will higher grades finally make a significant difference? The max pull force I saw with the weaker grade N38 magnets were 270 and 280 g. The stronger N45 versions maxed out at around 310 g. At first look this may seem like another disappointment for the higher grades... But if I put relative index numbers next to the absolute results it is easier to tell that the higher grades did make a noticeable difference in the paperclip test. Up to 15% better compared to only a 2 to 4% improvement in the distance tests. Now, this is an interesting base for testing what change it will make if I put the two N38 magnets together into a single, double as large magnet. How much better will double the size perform in the same tests? So in the name of amateur science it is time to take a risk and put these massive magnets together. I will as always use a wooden wedge to safely slide them together. Since I estimate the magnets will clamp together with a force of at least 200 kg at the end of the slide I tested if aluminium tape would have less friction than the wood. It just looks like the magnet slides easier on the bare wood so off with the tape... I'll consider investing in some heavy-duty teflon tape to make future projects easier. Okay - here we go! I'm going to hold my breath... [huuurp] - Oh, yes... - Uh-oh... - Come on... - God d*mmit! - Mmm yeah... - It took a bite... I was relieved when the wedge wasn't stuck anymore. But the little splinter left behind was bigger than I first thought. There's a clear gap between the magnets. They are not really put together... This is a failure... I was not pleased and off-camera I went viking on it and managed to twist the magnets a few mm back and forth slowly squeezing the splinter out. Here are the final few twists. Finally the splinter is out and the Siamese-twins magnet is ready for test. This big magnet should do well in the compass test, right? Not surprisingly this double as large magnet does well in the compass test It passes at 133 cm - way more than any of the single magnets. With the saw it also clearly performs better than any of the half-sized magnets. It passes at 16.1 cm. Over 2 cm more than all the single results which were only separated by a few mm. So no doubt that size does matter when working at a distance from the magnet. Bigger is better - while grade is less important. Try guessing how well the bigger magnet will do in the paperclip test? By combining the magnets we haven't changed the grade which seems to be important in that one. Let's give it a try! Okay... interesting! This very big magnet only manages 305 g of pull force with the same paperclip. Not enough to beat the half-sized magnets with higher grades. Clearly, grade is way more important than size alone when working on a small object in direct contact with the magnet. But why is this the case? I believe is simply the matter of distance. The added second magnet doesn't touch the paperclip. It is 2 cm away from it. Look at this test where I use the second magnet at a distance similar to if the first magnet was between them. The pull force is only around 30 g at this small distance. Similar to the extra pull force we see with the doubled magnet. Anyway, there's no big benefit in doubling the magnet's thickness and thereby doubling the cost of the magnet. That's why most magnets for sale are relatively thin. Extra thickness above 2 cm simply doesn't add enough power to justify the extra cost. Unless you really need - or want - the extra power. No matter the cost! Thanks for watching. Click thumbs up if you found this interesting enough to watch all of this loooong video. Hope to see you next time. Bye for now!

Channel: Brainiac75

Views: 1,426,622

Keywords: magnet, neodymium, monolith, big, large, test, experiment, n45, n45sh, n38, n38sh, grade

Id: asCp-wLQ0UU

Length: 13min 53sec (833 seconds)

Published: Sat Mar 11 2017