Music, welcome to another episode of ask first today:’s, question is what does sheet force be when dealing with magnets Music Music? These were all examples of sheer force, interacting with an item. In these examples, gravity was the source of the shear force, but gravity itself is not the shear force.
Shear force can occur in other situations as well.
A sideways force, interacting with a magnet, is called the shear force in many magnetic applications.
The holding strength of the magnet is affected by another force for inside way to the contact surface, for instance, in a magnet.
In I Frank, a magnet holds the knife, while gravity exerts a downward force.
These creates the shear force that effects the function of the magnet.
In this case, a magnet will have an effective oldest strength.
That is much less that the indicated maximum rdz folks pulling the magnets apart directly requires much more strength.
They’re separating the magnet by sliding them sideways against each other.
The shear force caused by the sliding motion lowers the effective or the strength, making it easier to pull them apart. Therefore, as we learn in episode, one, the best way to separate magnets is to slide them apart.
Silence when calculating the effect of shear force on magnets, the following general principle applies: neodymium and ferrite magnets only retain a holding strength of about 15 of the maximum indicated.
Adhesive force when the Lord creates shear forces Music, the effective Holda strength of a magnet can be increased by using rubber tape.
Silicone days pour by changing a surface which increases friction that counters the effect of shear force Music.
Let’s get back to our clapper boards without silicon knees and with silicon these once again, thank you for watching and don’t forget to send us your questions about magnets Music.
Hey, it's me Destin. Welcome back to SmarterEveryDay. You might not know this but every single hydraulic pump in every car you've probably ever been in has a little bitty magnet in it to catch shavings so that the mechanism doesn't foul up. Now, I know this because when I was growing up both of my parents worked at this plant and made steering pumps. The cool thing about that is that they would bring home the magnets that were out of spec and bring them to me and I got to play for hours and understand things about how magnets attract and how they repel each other. So, today I wanna talk about magnets. Specifically, I want to do a slow motion experiment with a little boy named Garrett who reminds me of my child-like fascination with magnets and then after that I wanna talk to you about the next great manufacturing leap in magnets. Printable magnets! It's amazing. Let's go get Smarter Every Day. Two "Rs" two "Ts"? [Garrett] Mhm [Destin] This is Garrett, two "Rs" two "Ts" Hello, Garrett [Garrett] Hello, how are you? [Destin] I am in Connecticut and Garrett brought something for me to do in slowmo.
What did you bring me, Garrett? [Garrett] I brought magnets that, I don't want to flip them right now 'cause that'll take a long time to redo but when you flip one they all turn together and almost instantly go back into one [Destin] And you observed this yourself, right? [Garret] Yeah [Destin] This is something you came up with and you want to do. So, we're going to try in slow motion right? [Garret] Once I flip this first part over and these are all going to fold over onto it Five, four, three, two, one, zero [Destin] That was really cool actually, Garrett.
That was actually very very cool. (laughter) Alright so… (laughter) [Destin and Garrett] Whoa… [Unknown voice] The force is strong with this one. (laughter) [Destin] And you came up with this idea, huh? [Garrett] Yup I was looking at them one day and I was making them into that and I accidentally flipped one and it did that. [Destin] Really? Alright! (applause) Playing with magnets as a kid was pretty simple: You had a north face and a south face and they would align and slap together.
But, now something else is happening. We're at a company called Polymagnet here in Alabama and if you look at their design you kinda get an idea of what they're doing. They can print specific magnetic designs on the surface of a magnet. Now, you've never seen anything like this because it's bizarre. You can get new, unique, crazy, behaviours just by manipulating that magnetic field. Let's go check it out. This is Jason Morgan, head of engineering. He's agreed to teach me about Polymagnets and show me some stuff that most people don't get to see. [Morgan] So, this is a conventional magnet. [Destin] Ok [Morgan] So, if you look at the conventional magnet [Destin] Wait, hold on, what is this? [Morgan] This is magnetic viewing film. [Destin] Magnetic viewing film. [Morgan] Yes. [Destin] Ok [Morgan] What that does is shows you transition in the magnetic field. [Destin] Uh-huh [Morgan[ So it allows us to see where the magnetic field transitions from north to south.
[Destin] Got it, ok. [Morgan] So, this is a conventional magnet it's a neodymium magnet. So, got a north face and a south face and the magnetic field goes from one face around to the other face. [Destin] Can we draw on the whiteboard? [Morgan] Absolutely. [Destin] We'll say this is our magnet here. [Morgan] Right. [Destin] So, the field lines are going to go out and in, right? [David] Yeah, you'll have, you know, closed loop, don't wanna break Maxwell's equations, all the way around from your north pole to your south pole by convention. [Destin] Gotcha, ok [Morgan] So, what we do different is we take a magnet and create pole regions on the surface. So, we create north and south on the same surface of the magnet and what that allows us to do is close that circuit that David was talking about in a much more compact space and that gives us a stronger field close to the magnet, a stronger force, close.. [Destin] Ok, so, I think I got it. So, what you're saying is if we've got the big loop here north and south you're doing the same thing only they're looping much closer together [Morgan] Correct [Destin] Like that? Even in on itself.
[Morgan] Almost. Right, so, what actually happens is you have the north and the south on one face the magnet and so what happens is we have the field go like this and so instead of this long field that can create interference and waste energy you have a tight field so that it's tightly controlled and you have the force really focus near the magnet. [Destin] These people are like modern-day wizards. They can create whatever magnetic field they want on any of these magnets.
I sat and talked with him for about an hour and came to understand that the way the magnet interacts with the target material determines how strong it's attached. And so what you're saying is the magnetic field in this one is going to come up and around and go all the way back to the back of the magnet, correct? [Morgan] Correct [Destin] Ok, in this one we have a tighter grouping of the magnetic field so the circuits are going through the steel and they're completing just outside of the steel on the other side, correct? [Morgan] On the same face of the magnet [Destin] Same face of the magnet.
So, they're not going all the way back around to the back side. Gotcha. Here, I have a very dense spacing of magnetic fields and so they're all completing inside the steel [Morgan] Inside the steel, correct [Destin] Do I understand magnets? [Someone off camera] You do. You understand polymagnets. [Destin] Polymagnets Let's say you have a piece of steel that's a certain thickness and you wanna attach this one-inch magnet to it. Engineers first design and print the magnetic field and input both the magnet and the steel into this pull test machine to quantify the exact force versus distance curve. If they want to they can then change the magnetic field and tailor it until they get the exact force curve they're looking for.
This ability to manipulate the strength of the magnetic field coupled with a really clever geometry allows you to create fascinating magnetic behaviors. For example, these magnets, they're attracted to each other but they don't touch. They stop just a few millimeters away and seem to hover. This behavior is what they call a spring. These are Springs. Alright this is a spring that's a little bit different it's a little more complex and can be used as a latch. So, you see that it acts as a spring so if you think about it, let's say, like a cabinet door closure. You could have a cabinet door that came together in a soft close with some, some shock absorption but then you could twist it to lash (Destin gasps) and it holds strong. [Destin] No way. So, I can pull against you, like that. I close it and then when I turn it.. [Morgan] Locks into place. [Destin] That's ridiculous. Time out! This is way different in your hands than it is on a video. Attraction and repulsion in the same axis in then you rotate and you can't pull it apart.
Now we know that any sufficiently mature technology looks like magic until you understand exactly how it works. Watch the faces of my highly-educated engineering co-workers as I put this in their hands. What's going on there? [Friend] I'm not really sure. (laughter) [Friend] That is weird. How does that work? [Friend] Ooo it catches. I have no clue. [Destin] So, if it's not magic how does it work? [Morgan] You have that locking point, where it holds tightly, but then you turn past.. (metal clinking) and it will hold in that spring location. [Destin] That's genius. That's gonna change doorknobs. I really think it is. Are you excited about that? [Morgan] We like this. We like this one a lot. Jason agreed to let David show me some of the special machines in the back that they invented program magnets. They look just like 3d printers only you load a blank magnet and it can create whatever magnetic field you can imagine. While we waited the five or so minutes it takes for these things to run, I went back out and met more magnet geeks and tried to learn more lingo.
You said a maxel? [Magnet Geek] A Maxel. [Destin] A Maxel is a what? [Magnet Geek] It's a magnetic pixel [Destin] Really? [Magnet Geek] Yep. [Destin] And so a magnetic pixel would be a node inside the magnet that's printed. So, the image that you just printed is created by magnetic pixels or maxels. [David] More or less. [Destin] Can we go look at it? [David] Oh yeah. Think about these maxels. Somehow this machine creates north and south polarized maxels inside the magnet. You can add these pixels up to basically make images that can create forces. If you couple one image with a complimentary image you can then create incredible three-dimensional behaviours. This technology is so new there hasn't even been enough time to think through all the different applications. I think it's a game-changer. I'd love to hear what you think in the comments and please consider passing this video along to all your smart friends to see what they think.
So this is the Smarter Every Day magnet. [Morgan] Yeah so we'll.. [Destin] Oh man! So, you could make a marble track. Could you do that? [Morgan] Give me a big enough magnet. (laughter) [Destin] This is bizzare. Alright so here we go, Smarter Every Day. We have a marble, And it follows the field lines. So, there you go. The entire foundation of magnetic circuit design technology just changed. I'm not gonna lie it makes me look at magnets just like I did when I was a little kid. Okay, my parents worked at that plant growing up to support the family. I choose to be an engineer and make YouTube videos at night so let's don't make this part weird because you're smart people you know how this works. Smarter Every Day is supported by audible.com and I would love it if you decided to support audible so they wanted to continue supporting Smarter Every Day. You know what's going on. Oh wait! Look at this! A printed magnet telling you the promo code.
If you want to get a free audio book of your choice go to audible.com/smarter I actually use this I'm not just telling you to do something because you know they support Smarter Every Day. This is something that will actually make you smarter every day so if you wanna support Smarter Every Day go to audible.com/Smarter to get a book of your choice. I would like that. Also I wanna thank Polymagnets, the group that actually makes these things, for printing all the crazy stuff this is an untapped potential. The medical field? What could they use this technology for? It's pretty impressive. Anyway go to check out their website they have some really cool features on there.
That's it. If this earned your subscription feel free to do that but if not I just want you to get smarter every day. I'm Destin. Have a good one..
Hi I’m Steve Jones. I’m, going to show you how magnets can attract and repel.
I’ve got two situations here: The first one where we’ve got two bar magnets, each with a north and a south pole, but the two north poles are close together.
The second here we’ve got the same two bar magnets, but this time the north pole and the south pole are closest.
Now, if you look at the red lines here, these red lines represent the magnetic field.
You can see that in the top diagram you’ve got a situation where the arrows are in the same direction, so they reinforce and create a stronger field.
Obviously it’s going to be weaker at the outsides.
It’s going to be weaker there and there There is a rule that there will always be movement to reduce the field so that it is even and it will always go from the direction strong to weak.
Essentially, these two magnets will move outwards.
They will repel because that’s the only way you can make this field in the center weaker, to match the field at the outsides.
Now let’s look at the situation here. You can see here.
The arrows are going in different directions, so they cancel each other out.
So the weaker part, the weaker field, is in the center and the stronger is at each side.
Of course, by the same rule, we’re going to find that the two magnets actually come towards each other.
They attract So here we’ve got attraction and we get attraction if we have got different poles together.
If we’ve got different poles, north and south, they will always attract.
We get repulsion if we have got like what did we say like poles or similar poles That is north and north together.
So the rule is like poles repel, Unlike poles or different poles attract, So that is simply how magnetic poles attract and repel .
