Hello and welcome to the English translation of the talk why 3d printed clothing is not the future Your translators for this evening are dark man and Mary So questions are who's who knows about 3d printed clothing and who's done that before Actually at home so there's not a lot of not a lot of people who've done that before and If so it didn't work too well But a lot of people have 3d printed who of them have thought about printing clothing actually at home so about 10 people have thought about doing that at home and our next speaker Rebecca will Tell you now why that might not be the best idea to 3d print your clothing You can find Rebecca on Twitter under using her handle core first in and she's doing research at the intersection between usual clothing manufacturing of usual clothing like everyday clothing and She also does a lot of She does the technical virtual clothing So I have a lot of fun enjoy the talk. I hope you're gonna have a lot of fun.  Oh more more post There's a lot going on on that stage right now. I'm gonna read that later, but I'm happy that the post office seems to be working well So my talk is called why 3d printed clothing is not the future and I'm gonna talk about the what what makes 3d printed clothing and Why it why it's like that and what needs to be done to make it Everyday usable So I'm a clothing technician, which is maybe a weird combination of words So when Clothing is manufactured on the one side. We have the design Did the idea and To put that into a real thing That's a whole different thing So for example, we have a person who comes up with a design they design a dress and Have a nice picture of it. You can see some things but not not too much and they go to production to to a company And tell them make distress place and they're like, okay how how we need a lot of information to do that and Everyone's like what and Yeah, that's where it stops because the production needs to know what kind of fabric do we need What kind of sizes do you need? How many do you need? How many in which size what kind of machines do we need what to put on the on the care instructions? How far is the distance between Between different parts of the dress and that's where where I came in like in between the design and the production so I kind of Do the reality check? What can you what can be done? How can it be done? So it's a lot about materials about quality Where to produce it prices when to produce it all of these question have questions have to be resolved And that's what my job is So this I applied this reality check how can this even went on to 3d print printing? And if you have a look in the internet for 3d printing and clothing Then you can see all these headlines about some news 3d printing will bring a lot of flexibility into the fashion industry or clothing of the future or is the street of the future from the 3d printer or can the 3d printer completely revolutionized fashion 3d was even worse. Oh Yeah, 2020 will all have a printer at home and in the morning We'll print a blower and in the evening we'll melt it down and print a new one But they got a bit careful over time But you can see even from these headlines that there's a lot of hope involved here That's something may change radically that the fashion industry will be unrecognizable And there is a lot of the sustainability in there And sustainability has become a big topic in the clothing industry and well, I'm gonna talk about that 3d printed clothing actually exists. It's nothing new nothing special not completely unrealistic There have been complete fashion collections that have been 3d printed. I'll show you three small examples For example the creations of Danny Pelleck They her final collection in Israel Was made completely via 3d printer. It was a five-part collection There's for example, there's two part ensemble to the right a top and a floor length skirt and the skirt Was printed completely with desktop 3d printers, which means it's made of modules that have about a four size And they're stuck together to form the skirt The special thing about is that it's it moves very well is very flexible because it's made from flexible filament but also because it has this zigzag structure structure that Enables the parts to move over each other when you pull on them It really Jumps it pops up a bit where you pull on it The jacket you see there is the first 3d printed ready to wear a piece of clothing that you can order online It's limited to 100 pieces If you want to buy it you can do that for one thousand five hundred dollars You can Make some decisions like change the color put some writing on the back And then it takes about hundred hours to print and then you have a jacket Another example is from the design collective nervous systems the kinematic system It's made of triangles that are stuck together with hinges So the whole surface is flexible it can be moved, but it's made from hard material So there's like a hard solid plastic it moves it rattles a bit if it moves if you run After a while they made a version That is proof against spying eyes the dress on the right Is made of these triangles but has little flower petals printed on it so that it can't be looked through The third example is this it is the pangolin dress It's made of a structure of different modules that can move into one another and overlap when moving And that allows a limited flexibility So you can move in this dress and the surface will follow your movement The Travis Fitch was working on this Designer working in New York, and I talked to him it. I am a clothing technician. I asked yeah, can I have numbers? And Where do you even get the information that these structures can be used for just what makes you say? Yeah, okay. This is elastic enough to use it as clothing redo lab testing and He was more like yeah, I pull on it, and it's either good or it isn't And so then the clothing technician in me sort of burst through and I thought hey, what am I numbers? And so I offered him to examine these structures to lab testing to find out What's behind all this what are the Aspects of this in numbers and units. How can you express that? So those were three of many examples at fashion shows on the runway. There are a lot more And it's of course clear that these aren't exactly Everyday examples there. These are clothes for a special occasion Custom-made can take months to build made of 300 whatever parts that have to be stuck together But the question is will this revolutionize fashion? so That obviously has to apply to everyday stuff Custom-fit stuff at fashion shows does not in directly revolutionized everyday wear So my question is what does this clothing have to do or have to be able to do to be everyday? Where that we can wear literally every day and for every occasion And to me at this point it's the most important part is that clothing has to be comfortable We can we can express that through Comfort very comfort. There's the psychological part of that which is about trends and individual individuality and that I'm I'm kind of Individualizing myself Wearing a hoodie might fit here, but Maybe maybe a more Different context would would ask for a different clothing And In this context you might feel very comfortable in in one kind of clothing Which you wouldn't wear in a different context and that's a psychological part then there's the next to skin comfort It can be it can be soft or kind of itchy or scratchy. It can cause allergic reactions There's the physiological Comfort which is about About the climate kind of like your body climate it has to keep you warm But at the same time it has to transport your sweat kind of to the outside and And So it can This evaporation must happen through the clothing So and some clothing does this a lot better than others and it's important for us being comfortable in our clothing And the fourth aspect is the ergonomics of the whole thing That's mostly about freedom of movement and that's kind of the thing I focused on The freedom of movement comes on the one hand How the clothing fits how tight how loose it is and Secondarily through elasticity of the material used And that's extremely important since there are parts of the body for example the knees and the elbows Where you have to have a stretch of at least 50% if you Want to perform any sort of useful movements and to do that The clothing has to be elastic and not break If the material used in this place is not elastic then the surface would either bow out or distort So if you have a very tight sleeve and the material isn't elastic and I do this all the time Then it'll sort of take that shape at that point and it won't look nice So we need a material that sort of springs back into its original shape once we straighten out our arm So if the surface isn't elastic at all it isn't actually that good for clothing uses But you can compensate for this with cut if the Piece of clothing is wider. It's the lack of elasticity is not as significant So My question was how can I find out? How these are elastic these 3d printed structures are if I can do that then I can use them consciously in a targeted way to significantly raise the ergonomics and comfort of 3d printed clothing and bring it closer to everyday usability and If you look at textile surfaces like the ones that we wear every day the they implement the elasticity Then there's two aspects the material itself may be elastic. It's usually called in a stand It's awesome. You can stretch it by 300% and it'll spring back And it's used in many many pieces of clothing. So a usual Mix ratio is 98% cotton 2% of the stand and those 2% are enough for the shirt to be Moveable enough to get in there. It can be very tight, but it won't deform or anything after wear the second option is via structure structural elasticity and That is usually done via weaving And if you pull on a surface then the threads will move and they will move relative to each other and Distribute a bit of their thread to their neighbors and that In combination makes an elastic surface with material that isn't all that elastic Cotton fiber for example is the last thing at all, but if you weave it the right way It's a very movable in the elastic surface And if you transfer this to 3d printed surfaces, then you can use an elastic material here for example tpu That's thermal plastic polyurethane Polyurethane is used in LSTAN So it has very similar Aspects and because it is based on the same chemical ground rules Structural elasticity is possible Via you can print a weave But you can also use other shapes such as arches spiraled springs Things you can compress or pull on So that at first you distort the structure and not the material The kind of things you could do with that depends on your printing technology. There are different ones and not all are The same for making fashion for my research. I specialized on two processes So for the one on the one hand IDFLM Method which melts filament. So it it's It's a thermoplastic so it's It's heated up and then it gets it melts and it's liquid and then You can you can design a geometry using that And if you if you have an object with that kind of hangs over Like you see on the left. You need you need some pillars to to help that stand and That structure like the pillar structure needs needs to be built from the beginning and It's in the finished object and you have to remove it afterwards That's no problem. If it's if it's a hard enough material you can just break it off But if it's elastic you can really break it off if you pull on it It's just elongates and you don't really win anything so if you if you try to To build geometries like that With with an overhang That method doesn't really work for it you you don't win any time or get any get anything out of it out of the method like that Functioned later with TPU. No, it's at least not with them. What's so often markets? I didn't catch Good idea, but it doesn't work with TPU for other technologies. You have BPA which can be dissolved in water But those structures don't really fit together TPU needs a very high temperature to melt. I printed that stuff at 215 C But the PVA already started decomposing from the temperature. So theoretically a good idea Right now it's possible with these printers. Yeah, it doesn't fit yet. I am of good hope. That's something new will be developed, but yeah The other process is SLS selective laser sintering It's a powder base printing process where you put layers of powder into your build space and Use a laser beam to melt the grains of the powder together where you need your geometry And then you add another layer of powder and so on So the powder itself is your support material and you can do away with all those columns You at the end you have filled your complete build space with powder and somewhere in there is the structure you printed And that powder can be easily removed later and reused for my research I Tested a variety of different structures the left and the center one are made with the SLS So I had the possibility to add a bit of height to Chain things together And I did that in different sizes The larger and a smaller variant and the smaller variant is obviously a lot more mobile You can really fold that up nicely and move it and these little modules Can be moved relative to each other you can push them together and that's makes it all very mobile With the other process I was limited In my design choice, so it's a bit simpler. This one is based On a diamond pattern that has been extruded into three-dimensional space And at first the diamond structure is stretched before the material actually moves I had this with different variants big diamond small diamond different layer heights To see Which variant has which elastic properties so that it can be decided which factor is the deciding one for the elasticity values I get How can you even test these values? By pulling on it you take a sample strip something like this Put it into your testing machine and the machine will pull on it with a constant speed But the in the software that works with a machine spits out a little diagram you can see it on the right and And the diagram shows you the change in length in percent, so How much it has been distorted and the force used So you can use the diagrams to How resistant the materials against tearing and how much it can be distorted without springing back and spring back Stretching and elastic stretching is not the same thing But if I pull on something and I stretch it It's going to keep its shape because I overstressed it But if it's elastic enough it will spring back into the original shape. Those are two Different numbers that can both be derived from this diagram I did that with all my different variants And you of course you have to do multiple samples and average them out and everything and Then I got numbers and units And so I had these numbers So one thing I have to know is are those good numbers are those bad numbers and For that there is a recommendation by Dialogue textbook Leidung together with the German fashion Association It's not an international standard is not a law so clothing doesn't have to reach these values, but is a recommendation how clothing should behave and what forces It should be able to tolerate. This is a small part of that split by product groups like Pants have to survive different things compared to underpants and if it's a bit looser then You need less pulling force because if it's further from the body it It's not important how much is pulled it doesn't have to conform as well. So I compared these numbers and found out The amount of force needed to permanently distort My structures was okay, but the maximum force before failure was not okay So I can pull on the thing that's awesome, but it's very easy to pull too hard and rip it apart so yeah, they are flexible but the forces if I Move my arm and the thing rips then the piece of clothing doesn't help me much these 3d printed structures are limited in that sense Then I want to have a look at the factors that actually cause this to be elastic or not or how much And what I saw from my numbers is that the size of my elements Did have an influence So the larger variants had better values than these small ones but The big ones don't really look or feel all that much like fabric But the small the smalls are closer, but they didn't get as good numbers and then there was another factor Which was the slicing program? and the slicing program Has two significant jobs First of all, it splits my 3d object up into layers and second of all It details the 3d printer where It's supposed to be in which layer with a printhead. So if you print a vase like this The lowest layer will be completely filled because you want to pour water in there. It's not supposed to leak out So the path from the printhead or the path of print head could look roughly like this It will go back and forth and rose to fill everything completely The second day will be a ring and the printer might be doing something like this. Maybe we'll take another path though there is a lot of different programs and There is a They are limited in their configurability And I had a closer look at it and saw that With my diamond structures the printhead took a fairly particular path. It went Over to this crossing and then back in another direction Under the microscope you can see that it tore exactly here The printer didn't actually traverse the crossing So all the strands are just ever so slightly melted together whenever a new hot strand came their way It's sort of stuck to the other But this trend didn't actually bridge the gap. So that's sort of my point of failure And that's where it tore apart And another variant which is based on basically the same pattern the slicing firm decided to do it differently It decided to go right to the bend in the middle of the diamond So of course the fracture point is now there and the samples look different because they tore in a different place and That explains my low yield strength Because I'm not actually pulling on the solid material But on the places where it's just sort of stuck together a bit and depending on how well that happened This can be easier or harder So the method itself itself already makes some makes the strength kind of low So I've tested eight structures using different variants So you could ask now How do you come up with the idea that now 3d printed clothing isn't a good idea and that other things might be better And I say well Could be and depending on the method you use there's there's boundaries to What how far you can get so here we have to take a closer look actually on to molecules on the molecules itself so different different strings have have different different They have different tensile strength due to the way the molecules are arranged so we have either amorphous or crystalline areas and Those that the squiggles to the right They are supposed to be chains of molecules and where they're sort of tangled together a bit like a Spaghetti, they're not exactly that stable in the areas where they're very ordered They are very solid and the natural fiber Have a tendency to be or to have a high Amount of internal order many crystalline areas. They are very solid They have a high tensile strength from the get-go that my structures do not have and if we're looking at synthetics Then you can influence how hard they are to tear There's different technologies to make fibers and At least one of them is very close to 3d printing in which you liquify or The plastic or the material that you want to use as a fiber and you press it through a nozzle And it turns into five minutes very similar to 3d printing the difference is that You can influence what properties the fibers at the end the degree of crystallization So how much of the thing is crystalline is dependent on how fast it cools The slower you cool cool the fiber the more time the molecule chains have to go into an ordered state So these spinning machines are heated for to cause the cool to be as slow as possible to get Degree of crystallization. There's as high as possible and hence a tensile strength as high as possible We do not have this possibility with 3d printing. We can use a heated print bed But that only infuses the first one or two layers maybe and nothing after that After the strand has been deposited we wanted to harden as fast as possible Since it might just run off to the side and we want to have a certain geometry that we decide we wanted to have it's not supposed to flow apart once it's been printed and When the next layer is added well that only works if the layer below it is already hardened So we can't just keep the thing at a constantly high temperature all the time with the SLS printing. It's a bit different It's a better for making high tensile strength materials And the structures had significantly better results as far as tensile strength goes With synthetic fiber we have another possibility Which is stretching them After they've been spun They are shoved through rollers and these rollers pull on them Apply a pulling force and that Raises the degree of crystallization Because the molecules are aligned and forced to align to each other This also leads to the fiber becoming slightly thinner and it becomes finer softer, but more solid That explains why textile fibers are so much more solid Then but still much finer than what comes out of a 3d printer textile fibers Can also warm you very well by trapping air for insulation purposes you get these little chambers due to the weave and Those can warm us And that's because textile surfaces are made of threads these threads are made of fibers And as you can see on this microscope image, it's this is not some rough carpet This is a microscopic image of a very small piece of cloth. You couldn't even see this with your eye but in all these little holes air can be trapped and You'll be worn by it. The small distances are also possible Important for transporting moisture because sweat can evaporate and go through them so the clothing can warm you and protect you from overheating and Structure small fine structures like this can't be made by 3d printing. We are very limited in fineness and We can't just print tiny air chambers We're still quite limited in that There's a couple things that 3d printed structures just can't do but there's other things that they can do so we can We have a lot of freedom of choice and when we design a thing So Things like bracelets or necklaces or glasses We have a lot of freedom to design that or for costumes in the movie exam for example Black Panther day 3d printed the crowns, which is one example what you could do with that method So you only you only build up material where you need it, which is which is very sustainable in Normal clothing Manufacturing if you cut a pattern from fabric you You usually have like 10% loss of the fabric, which is not a good thing. You lose a lot of fabric there So this is one of the good aspects of 3d printing clothing And you can actually recycle the materials Very well, which is another downside of the normal clothing industry It's very well suited to to to fabricate individual pieces One one of a kind pieces And you can have one product with different Different properties in different parts of the clothing So you could make it thicker for example around the shoulder if you want it more stable there and if you would try to do that With the usual way with fabric you would have to use different fabric there or added fabric and You couldn't just print it in one go like the 3d printing You could also integrate cables LEDs some sort of sensors Well, there's a question mark behind this because it's not really everyday stuff and We can't yet get that in such an advanced state that it's standard One advantage could be that you can make the entire piece of clothing in one single step Right now you have to first make the fabric cut the fabric sew together Maybe dye it those are all different steps happening in different places and If I 3d print a piece of clothing They could just do it in a once-through process But only if it actually fits into the printers build space So if you print an a4 sheet and stick many of those back together Then we're right back where we started where things have to be built out of components Something a bit more complex is this thing Nova systems develop which is a software that digitally folds the dress and it is printed in a folded state Which reduces the build space significantly So somewhere in this powder block you have the dress and you have to sort of Archaeological free it from the remnants of powder clean it and Unfold it, but it's it's a nice way of using the advantage of 3d printing of everything happening in one step But aside from that I still see significant problems There are also disadvantages or challenges such as the tensile strength or lack thereof which is a feature of the process itself We're limited as far as fine structures go So the standard nozzle diameter is 0.4 millimeters and with fibers we're looking at micrometers Those are significant differences and Fineness is important for how something feels on your skin for transporting moisture For warming via trapped air and that is so elementary That these four aspects of comfort just are not happening If the piece of clothing at 3d is 3d printed Time and cost is looking very bad It takes quite a long while to print and it's very expensive So this isn't every day yet. This is custom jobs How to wash or clean one of those things is Has to that has to still be determined How you wash it and if we're talking about clothing we have to talk about how do you close it? You have to get in there somewhere so they have to be zippers buttons hooks eyelets You have to think about that sort of thing if you want to print the whole thing once through So Building fabrics from fibers from threads which are made from fibers right now is not To be beat as far as comfort goes and there are no real solutions for imitating it either the via 3d printing or some other process Or some other arrangement of material On in a different way. This hasn't been solved yet That means that Right now state-of-the-art 3d printed clothing is not only not the future but not even today Because today our stuff is made of textile fibers It works really well, but 3d printed structure. It just can't do that yet That doesn't mean we should stop looking at the problem and whoever said that would work well I'm interested in what worked well, and if there are maybe other aspects involved that I didn't think about here but It should be forgotten that the basic or the basic functions clothing should be forgotten this Art I showed in the beginning is awesome, and I think it's the best thing ever and Research on that sort of thing should be done But clothing is supposed to warm us and it's supposed to protect against prying eyes and Supposed to keep our body climate optimal My hope that with a sustainable process we could maybe revolutionize the entire injury industry or through other that we could do that through new Production processes that's a bit problematic Since the fashion industry is highly problematic. There are many problems ecologically societal problems And putting your hope in a new technology and saying yeah, this will solve everything because it's sustainable And then we're just going to print everything with 3d printer and the sustainability problem will be solved That's yeah, I'm not seeing that So yes, please do the research, but don't forget the basic function and Don't just sort of rest on your laurels that this new innovative technology will solve everything so Revolutionize the clothing industry in all other aspects as well and don't depend on 3d printing solving all the world problems And this I'm done with my presentation and thank you for listening This has been the C3 dingo English translation of the talk. Why do you 3d printing is not the future your translators were And duck man For your information, there will be no q&a since this talk ended basically at just the right second You can ask the better things on Twitter for example a cool system And you could probably catch us somewhere after the talk As far as the translation translation goes we accept feedback at the email address hello at C3 lingo.org Or you can Twitter using the hashtag


Welcome to ITU Telecom World's 2019 from Budapest, Hungary where I'm very pleased to be joined in the studio today by Dain Amad, who is the CEO of a company called Chameleon from Mozambique. Welcome to the studio. Thank you very much for this opportunity. Now, tell me a little bit about what you do and I believe you developed a new product that you've been talking to people about here. Yes, I developed an infrastructure which is patented in the UK. The infrastructure is basically to attend rural communities with digital education programs. The reason why I did provide these services to the communities is because in these days everybody is linked to the digital. Even us, if we want to know something we don't even read the big books anymore. We use digital tutorials, we go to YouTube. In one or two minutes we can learn anything that we want. So my thought was why not do the same considering the conditions of rural communities which are very poor. So we developed the product, it's called the Tablet Communitario. In English you can translate it as a community tablet. The idea is we go to the communities, we provide videos, education videos. People can see the video. Our infrastructure is linked also to the speakers. The videos they see on a very light screen is about 110 inch. By seeing the video they can quickly understand what we are trying to provide them. We also facilitate video conferencing so people can eventually communicate if they have any questions. And on the other side we provide gamification where people are submitted to virtual games on that specific topic. So we have a feedback if the people are understanding or not that specific topic. Recently we've been doing as well health programs in Mozambique for the past two years. We've been involved in cholera programs. Some provinces had problems with cholera, with HIV, with family planning. And we realized that by showing the videos to the people they changed the behavior. And we also take the chance to do the digital inclusion because most of these people don't have access to the new ICT devices. So apart from videos themselves, essentially we're looking at literacy, is that right? We're talking about messaging, we're talking about civic education. How are you managing this content? How are you evolving with this? I'm talking about civic education. We provide content. We have a partnership with the biggest university in Mozambique. Because when you provide the content we have to take into consideration where are we going to present. Because of different religions, cultures and habits we cannot just provide any content. So we prepare the content with the university related to health topics. And we prefer to use cartoon animations because we can put the characters according to their lifestyle. So they can identify themselves there. And recently we have incorporated a vaccine freezer on our trailer. So the big idea here is in these days it's very difficult to tell people what to do. It's difficult for you to go to a community and say do this. But with our platform we can have the live screen. We provide the video regarding the vaccine campaigns. People can see, then people can ask questions because we have a virtual attendant as well. And when people are convinced which most of the time they are, there's a vaccine freezer. We usually go there with a doctor in cooperation with the minister of health. People get the vaccine. And on the other side of the infrastructure actually we can provide a registration. The user can be in front, take a picture, put fingerprints and we can provide the PVC card. So he's actually registered. And we also avoid double vaccination because you already have a vaccination card. And we also can incorporate blood freezers because in these days very few people donate blood.  So we have a dream to increase the blood bank around the world. So the people in rural communities can have the facilities also to know why to donate blood, how to donate blood. And on the spot we can collect blood, put on the appropriate freezer, register the people as well. But before that we can also have the facility to test the people if the blood is okay to be taken or not, type of blood. So we actually offer these type of facilities directed to rural communities. And what about funding? Obviously you're taking this technology, you're connecting people who are unconnected. And what about funding? How are you supporting this endeavor? Well, I do work in partnership with non-governmental organizations and with governments. So basically what happens here is like on a specific programs they hire me to do. So they tell me go to these places and stay one month. I give them the fee and I go and the end user does not pay anything. But the government or the NGOs, they find me to go to the places and to help them with this type of solution. And you're here on the Mozambique stand here, is that right?  Yes, I am from Mozambique. I'm here of course representing Mozambican product, but I have my own stand. And I've been having a lot of opportunities to talk to people in this field of telecommunications, health. It's been good so far and I'm happy. Great. Well, we're very pleased to have had you in the studio and it's been a fascinating insight into the work that you do on a daily basis. And the products that you've been developing. Well, we very much look forward to catching up with you again at some stage in the near future. And we wish you the very best of luck with all your endeavors. Thank you so much, sir. Thank you.


These are really a good way of doing reality checks because you can just put the sticker on the wall And then every time you're about to turn the light on you look at that and think oh Am I dreaming? I've actually I've actually got a load of these by the way just here ready to give away I'm trying to think of a good giveaway that will be you know, that'll make sense for you guys Hey guys, so this is the new setup for my sort of home office Scenario thingy this which is for video editing, which I don't I don't really use it that much at all But got whiteboard and notice board so that every time I walk out of the door I'm reminded what I need to do things. I'm waiting to review or things I'm waiting to sort of sell on and then we've got the main desk here Which I wanted you know as much light to come in as possible from these windows So that I can do videos here possibly put the tripod and camera here or Have the tripod and camera on the bed and then sort of and this is a cool little corner thing Eventually, I want to have a giant shelf going all the way up like that Basically, I'm waiting for a tripod to arrive because at the moment this one's tiny So I can't really use this one, you know properly to make videos. There'll be a lot of more improvements for this channel going forward At the moment, I'm sort of trying to review this little necklace thing Now this is I'm not going to do a full review on this at the moment because it's you know I need to use it for a couple of weeks and test it out and try that basically It's like a new totem that you can wear around your neck. It's a brand new product It's not even released yet So I can't actually show you where to get this yet, but you know keep your eyes peeled It's gonna be coming out of very soon. It's not mine. It's a product that's out there That's really cool that I've been sent to have a look at so really I just wanted to ask you guys What you thought I should focus on, you know, what questions you want to have answered And just to sort of encourage you to leave comments in future videos Just telling me what you think What you need help with I am trying to go through all the old comments in the videos But there's so many of them that you know, it's kind of it's so hot here today. I'm my head is just on fire Oh, I'm trying to grow my hair out by the way. That's it for now guys. See you next time


My name is Salim al-Haq. I am a senior fellow at the International Institute for Environment and Development and also director of the International Center for Climate Change and Development based at the Independent University Bangladesh. And I'm going to talk a little bit about the upcoming eighth international conference on community-based adaptation that's going to be held in Nepal from the 24th to the 30th of April. It's a seven-day-long event in which the first three days people will be going out to the field in batches of about 20 to 25 and spending two nights and three days hosted by a local community looking at what they're doing to adapt to their conditions, particularly the vulnerability to climate change, issues related to their adaptation activities. And then everybody will come to Nepal to Kathmandu to the capital where we will have another four days of sharing and discussions. The theme for this conference is on financing local adaptation. And we have chosen Nepal for a particularly relevant reason, which is that in Nepal, the government of Nepal has decided at the policy level to allocate 80 percent of the global funds that they receive for adaptation to climate change to the local level. And they have developed a very innovative local adaptation plan. It's called the LAPA, or Local Adaptation Plan of Action, that they implement at the very local level through the panchayats, which are the smallest units at the local level. So we want to highlight that practice and share it with the rest of the world. We're expecting roughly 300 people from all over the world. We have some very important dignitaries coming. The conference itself on the morning of the 27th will be open by the Prime Minister of Nepal. It will be addressed by the chair of the Green Climate Fund, Governor Salseda from Philippines, as well as the chair of the Adaptation Fund under the Framework Convention, Mamadu Hunadia from Burkina Faso. We also have senior representatives from private sector finance, the Munich Refinance, the Rockefeller Foundation. And on the closing day, on the 30th of April, we will have the executive secretary of the UN Framework Convention on Climate Change, Ms. Cristiana Figueres, there as well. So we are also hoping to bring out this time, on the 30th of April morning, a Kathmandu Declaration on Finance and Local Adaptation. And we are already in the process of drafting that declaration, which we will discuss during the conference and finalize on the last day and release. One final point for those of you who may be interested in following it. From the 27th onwards, we will have some live webcasting of the opening session on the 27th and the closing session on the 30th. I will be doing a daily video log of log on the proceedings of each day. We will be interviewing some of the participants and video logging them and uploading them on the website. So quite a lot of material will be made available on the website. We're going to be using social media and Twitter. The Twitter tag is hashtag CBA8. And we encourage all of you to register as VIPs, which in this case stands for Virtual Interactive Participants. You can register online at www.CBA8.org. And I hope you will register and follow the event in real time.


Lately, you've been making a very serious comment on matters of governance. One of them that you commented with displeasure is the appointment of the former presidential spokesperson, his appointment to go and serve in the Republic of Tanzania as a deputy high commissioner. Yours and your expectations were that it should have been fired completely and not redeployed in any way. Because you felt that allegations leveled against Mr. Bwadia, amounted to dismissal completely. Yes, if off on our hands today, and I share and talk about, first of all, Bwadia is my young boy. Okay. We don't want that. We don't want corruption, because we give leaders to serve in government, in his councils and other with pride. Okay. Number one, why is I saying that now it's the participating corruption? That is a very big embarrassment to the community, because Kavushi, it's all about family affairs. So my comment on my young brother, Anton, what? That's why I was asking, say, on allegations, you decided to comment like that. Amalumaz are the one who took over the team. I went to Anton Bwadia, Bwadia, $600,000. Amalumaz. So, Amalumaz in Gaya Ch'ine, Amalumaz in Gaya Ch'ine. First of all, to achieve that, you can do it. You can do it. You can do it. I am Amalumaz in Gaya Ch'ine. No kuya kutanzania, teringiri okuya kum, but presidenti. Mutti anfi anifi. Just show leadership. Mutti anfi anifi. So that we can even see that okay, but presidenti ch'ine is fighting corruption in the country. Okay. Mutti anfi anifi. So, Anthony Bwadia, No problem, but the biggest thing is that I'm in good boots now I'm done, now I'm done. I'm done, now I'm done. I'm done. I'm done, now I'm done, now I'm done. I'm done, now I'm done. I'm done, now I'm done. I'm done, now I'm done. I'm done, now I'm done. I'm done, now I'm done. I'm done. I'm done, now I'm done. I'm done, now I'm done. I'm done, now I'm done. I'm done, now I'm done. I'm done, now I'm done. I'm done, now I'm done. I'm done, now I'm done. I'm done, now I'm done. I'm done, now I'm done. I'm done.


Well, the last time BSU men's hockey team won a game in regulation. We have to go all the way back to November 22nd, 5-3 over Princeton. Since then, two losses in two ties, including in game one Friday night against Northern Michigan. The Beavers doing everything they can to get a W game two Saturday night with the Wildcats. They're down one of the first, but Carter strutters from the point. That's Sneak's home. That's his first goal as a Beaver and ties it at one. Then the second, now 2-2. But Hampus show it all, gets behind the D. First shot's gonna be stopped, but he lights the lamp on the rebound. That's also his first goal as a Beaver and gives them the lead. Northern Michigan, those scores are next two to go ahead, but with five minutes left, Miles Fitzgerald on the power play. We had extra time. Nothing happens in the OT, so now a shootout for the extra point. Robbie Payne beats Michael Bitzer. So, Mr. Automatic J. Dickman has to answer what he's denied on the backhand attempt. It officially ends in a 4-4 tie. Beaver's missed out on an extra point. Again, they've fallen the shootout one, nothing. If you've enjoyed this segment of Lakeland News, please consider making a tax deductible contribution to Lakeland Public Television.


So, we will continue with what we were doing in the last class. We were looking at a broad picture or perspective of vehicle dynamics. So, we were looking at how we are going to approach the subject of vehicle dynamics. We said that for us though there is a vehicle, it has its components and so on, when we are studying vehicle dynamics, we said the center of this whole thing is the mathematical model. So, mathematical model comes from our good old Newton, Euler-Newton equations and this has an input and an output. Remember that when we looked at the dynamics which is defined by using this mathematical equations, they are classified into what we called as longitudinal dynamics, lateral dynamics and vertical dynamics. We said that we classify the dynamics what we are going to study using this mathematical model into a longitudinal, lateral and vertical dynamics. We also said that for these of understanding its effect, we may most of the times delineate or decouple them and study them in isolation. Is that correct? Does it not have an effect or one has an effect on the other? Yes, there is, it is possible there is an effect but in order to understand the subject, most of the time we will be decoupling the effects of all these three. There are very important things that will happen like load transfer and all that. We will understand it as we go along. We also said that the input for this model is the driver's input through the steering or the acceleration and braking. In other words, how the driver interacts with the vehicle. That is what we are going to use as an input. We said that we cannot look at every scenario by the driver and we will have some test conditions in order to understand the behavior of the vehicle. Of course, we said that the vehicle itself which goes into this mathematical model will be defined by means of certain parameters, what we call as kinematic and compliance parameters, mass, moment of inertia, as compliances, stiffnesses and so on. The output from this model as we said yesterday are in terms of displacements, accelerations, velocities and so on. We said that what comes out as an output has an effect on the occupants and we are going to study that not to a great extent but at least as an introduction we are going to study how this is going to have an effect on the occupants. This is the broad, I would say, basis under which we are going to study the subject. We also said that we can again look at it from a different perspective and call this as driving dynamics, safety, right comfort. When we look at this from a different perspective, same problem, we are going to look at it from a different perspective. So, it is not organized like this. It is not that longitudinal dynamics is driving dynamics, lateral dynamics is safety, vertical dynamics is right comfort. It is to a certain extent it can be looked at it like that but they are not necessarily a clear demarcation like what we have here. So, we would look at the safety during driving both in the longitudinal as well as in the lateral dynamics, right. We will continue now with this short introduction and we are now going to look at this mathematical model and already we know or we had a very, very, very simple model in the last class. We are now going to extend this model, simple model into not a very complex model but just the same model, simple model making it more elaborate. It is not going to, we are not going to make it very complex. We are going to use the same equations f is equal to ma. So, in other words, we directly plunge into what is called as the longitudinal dynamics and look at a very simple mathematical model that we will be using in order to understand the longitudinal dynamics. Whenever we talk about dynamics, two things that comes to our mind, the very first thing are the forces that are going to act on this vehicle and the other is of course, the acceleration or deceleration and so on. And our good friend f is equal to ma from Newton is going to be of great help in writing down this mathematical model. So, the first things first. So, what are the forces that are acting on the vehicle? All of us have experienced this. The first one of the external, we are looking at the external forces. The external force that acts on the vehicle is what is called as the aerodynamic force which we would call as r a. The other force, next force which is important to us, which is acting on this body is the gravitational, pull or gravitational force and that and write it as m g or w and that can of course, be resolved into two directions like this and that if this is equal to, this is of course, is equal to theta s. So, if I call this as w, then we have, what is this w cos theta and w sin theta. You may have a trailer, you know, towing with this vehicle, which is called as a drawbar. So, if you have a vehicle or if you have another trailer with you, then there will be a drawbar pull which you would call as f t, clear? Apart from this, the vehicle itself is going to give us some force, some nice guys, some not so nice guys. So, if I am going to accelerate, we need what is called as the traction force. So, the traction force is now going to act in that direction. So, let us say, let us put the traction force in the front and the rear. Let us look at this tractive force and call this as FF. Of course, in every vehicle FF and FR will not act together or it may be a front wheel drive or it may be a rear wheel drive and so on. So, depending upon the front and the rear wheel drive, you will have either of the one or if it is a four wheel drive, then you will have all these things. Apart from this, one of the very important forces which consumes our fuel is what is called as the rolling resistance of the tire. The rolling resistance of the tire acts opposite to, we will understand this rolling resistance in a minute, it acts opposite to this tractive force and in fact, it is something like a breaking force that acts on the vehicle. Now, what is, let us first understand, see up to this it is not very difficult to understand all the forces that are going to act. What I am going to do is, what I am going to do is very simple. I am going to find out the reactions of the front and the rear. Let us say that we are accelerating force, we are applying a tractive force. So, we can say that I have a D'Alembert's force. Actually, it is not a force, it is a pseudo force which can be written as W by G into A. It is not a good practice actually to put this D'Alembert's force. It is nice to write F is equal to M A, but then when I take some moments, then it becomes easier for me to have a force there and that is the reason why I have a force and call as the D'Alembert's force. Now, all these forces are familiar to you. In order to take the moment, of course, you need some dimensions. So, let us call the dimension something like this. Let us say that, that length is equal to L 1, that length is equal to L 2. L 1 is the distance from the front wheel to the CG location. L 2 is the distance from the CG location to the rear axle, the rear wheel and let the total length of the vehicle L 1 plus L 2 let it be called as L. The other thing that is important to us is the heights.  You know how to determine the two W's or the reactions at the wheels W f and W r, if I want to find out W f, I take a moment about W r with proper signs, I can determine W f. In other words, W f into L is equal to whatever the moments that are due to the other things. But before we go further, there are two comments that are important to us. One is the system that we are going to use in this course. The x, y and the z direction that we are going to use in this course. This comes out of an ISO standard and we call the direction which is along the direction of travel as x perpendicular like that as y and the other direction normal to the ground as z. So, longitudinal lateral and vertical directions. Of course, you know that there are motion, the angular motion along these directions. For example, the angular motion in the direction of x, in other words that angular motion along the direction of x, let me think that has to be a correct one. Let us say positive, that is positive is called as, what is that angular motion called as? Roll. So, this is the roll and the angular motion here, which is in the y direction, that is that angular motion is called as the pitch and that is what we call as yaw. So, when you say colloquially pitching, that is moving in that direction. So, that is the first thing. The second is, let us go into the details of what is called as rolling resistance. Rolling resistance is today very, very important for fuel consumption, especially in trucks can imagine that the rolling resistance whose origin are the tires consumes nearly 30 percent of the fuel of the vehicle. We are going to do quite a bit of tire dynamics in this course, but let us understand what is rolling resistance and how do we get it. Quickly, we will go into details later just to understand, because I am putting a force there. So, you would understand what this rolling resistance is. Now, there is a misnomer. Many students assume that the rolling resistance is just the frictional resistance of the tire, absolutely not. It is not the frictional resistance. Rolling resistance comes from the property of the elastomer or rubber, which is the material of the tire. Elastomer or rubber as it is called, that is what goes into the manufacture of the tire. Elastomers have a property called viscoelasticity, usually depicted by a dashpot in order to understand, in order to understand the effects. Now, what is this viscoelasticity and how does that going to have an effect? We will see that in a minute. As I said, we will elaborate it later. Any material can be looked at, small digression here. Any material can be looked at from three simple models, one a spring, other dashpot and third one is what I would call as a friction. Suppose, I say that a material is purely elastic, then you can say that the material can be represented by means of a spring. This is not a very correct representation. We are not going into too much of details. We can say that spring, a linear spring especially, is good enough to model say, a linear elastic material. It is something like an understanding of the material behavior. A linear spring, where the force is proportional to the displacement with the stiffness k, can be looked as if it is the material and k is something like E. When I leave the force, the spring comes back to its original position and that is what we loosely call as elastic. Now to this, we can add other material behaviors. For example, if you look at elastomers, elastomers are elastic, of course elastic and then viscous behavior. So, in other words, spring comes because I can model elastomer or I can understand elastomer as if this is made up of a spring and a dashpot. This dashpot can either be attached in parallel to look at it or we can understand the behavior by attaching it like this and so on. There are names to these models, Kelvin and the Maxwell models, but we are not going into details of these models. We are putting this in order to understand the behavior. For example, if you have a metal which you are taking into the plastic region, then I can model this metal using the spring and the friction element. So, you can join together in parallel also. So, you can model series and so on. These elements you can join them and then write a mathematical equation which can form the basis of the constitutive equation or stress strain behavior of the material. Now, we are not going into this as I told you into the characteristics and I am not going to write down equations here. We will understand only the elastomer part in this case. May be pass a comment afterwards about this friction and why friction is used to model what we call as plasticity. Now, what is the difference between an elastic material, the viscoelastic material? Sometimes people call this as hyperelastic, viscoelastic material and so on. First of all, let us understand that elastic material is not necessarily linear. It can be non-linear elastic as well. So, if I now have a load deflection of the stress strain curve, when I load it, I load a material which means that I am applying forces. I keep increasing the force because of which the stresses increase and there is increase in strain and so on. So, when I load the material, let us say that the path taken by the stress strain curve is something like that, goes like this. When I unload a material, an elastic material, it would actually, all of you know that it would follow the same path. On the other hand, a viscoelastic material does not follow the path when it is unloaded and would now follow a different path and that amount of energy is lost and usually called as the hysteresis loss. So, there is an amount of energy that is lost. It is the same as plastic. There is a subtle difference, a good difference that though at the end of loading, there is a residual strain here. The strain will come back to zero with time. So, time is an important factor in viscoelasticity. Time and frequency are an important factor in viscoelasticity. So, in other words, what I mean by time and frequency are important is that the material behaviour is affected by the rate at which you load it or in other words, the frequency at which you load it and so on. So, time and frequency are important factors. So, the first thing is that to conclude whatever we have been saying that there is a loss of energy when the material is loaded and unloaded. How is it going to affect us? Why is it that the tire should develop a rolling resistance and that is what we are coming now. Now, let us say that obviously all of you know it, but I am just reiterating what is well known. Let us say that I have a tire. We have what are called as treads. Let us say that that is a tread and that is the ground. So, this tread material as it approaches is going to get, let us say that it gets compressed and then again gets released. Why tread? The material inside the tire which we are going to see what they are also gets compressed and released or in other words, there is a loading unloading cycle as the tire rolls, a loading unloading cycle as the tire rolls similar to what you see in this stress strain curve. So, in other words, if I go and sit here in this tread and go through the cycle of rolling, I will go through a compression and then whole compression. As I come here, I get completely compressed.  Because of this cycle, I lose energy or there is an hysteresis loss. So, this is now who is going to compensate for this hysteresis loss because your vehicle has this tire and tire is losing energy. So, who is going to compensate? The vehicle has to compensate. The vehicle has to compensate. So, the first thing is that because of the material of the tire, there is a lot of advantages. Why then rubber? Let us not talk about that because a lot of advantages, we will see that. So, because of the material with which this tire is made off, we have a hysteresis loss and the loss has to be compensated by the engine ultimately and so this opposes the motion. Now let us understand how did I get this force? I said that there is a rolling resistance force, which let us call this as FR, rolling resistance force. It can be the front and the rear. So, how did I get this as a force? So, in order to understand this, we have to look at what is called as the contact patch of the tire. What is a contact patch? A patch that is formed obviously by contact of the tire with the road. In other words, more precisely it is the pressure distribution at the contact. It is a pressure distribution at the contact. So, what is the pressure distribution? We will see the three-dimensional pressure distribution later or rather two-dimensional pressure distribution later. Now, let us understand a section of this pressure distribution. So, let us say that I come into contact at that point and leave contact at that point. In other words, that is where my contact is. It is not necessary that the contact pressure exists only when the tire rolls. When the vehicle is stationary also, you have contact pressure. Let us for a moment stop the vehicle and look at this contact patch. So, the contact patch now is not that of a one tread, but there are number of treads. So, the contact patch would look something like this. In other words, rubber is symmetrically compressed about the center. This is a vehicle that is standing symmetrically compressed about the center. So, whatever is the force that is compressed by this and it has to come out in the other side. Whatever is compressed has to come out the other side. Now, let us understand one or two more things about tires before we go into the details. The first is that the tires that we use are what is called as pneumatic tires. In other words, we inflate the tire to a particular pressure. So, many of you may have driven a car even now when you go to a gas station to fill your or inflate your tire, still you talk in pounds per square inch units, 32 psi. If you are driving a huge vehicle truck, it is 120 psi and so on. So, let us go into some details and look at this section from this angle. So, let us say that the tire, that is how it is deformed. Let us say that the tire is deformed like this. So, when you look at it from this section or whatever be the section, that is how the tire is deformed. For a moment, I am taking out the tread and I am saying that the tire has a thickness something like that. That is what is the inflation pressure which we have used in order to inflate the tire. When we inflate the tire, we get what is called as the inflation pressure. So, now we know very well that we know very well equilibrium equations. We know very well that whatever infinitesimal element you take should be under equilibrium between the forces that are acting on those infinitesimal elements. So, obviously, when I take an infinitesimal element here, I said contact pressure is what is acting in that region. So, if I want this to be under equilibrium or if I want it to be under equilibrium, then the pressure that is acting, the contact pressure that is acting should equilibrate the inflation pressure when it is full contact, when it is full contact, when it is in full contact. So, the contact pressure should be equal to the inflation pressure. Contact pressure should be equal to the inflation pressure. So, strictly speaking, the contact pressure should have been uniform. But, contact pressures are never uniform. We will see more about it a bit later because of the inflation pressure, the local bending because of the bending of the side walls, these are called side walls and all that. So, the contact pressure is never uniform. It has a particular shape. We will study this after two or three classes. So, now let me come back. So, in other words, there is a lot of theory as to how contact pressure develops, how contact pressure is distributed, whether it is uniform, whether it is not uniform and all those things. Now, here when I talk about this, I am only talking about the pressure because of the tread as it travels along the or around the circumstances, I mean, circumference. So, here I am looking at the pressure on the tread. So, the pressure on the tread compresses, goes to a maximum and then gets released. So, let us not right now confuse between this and this. We will come to that later. So, the contact pressure, what we are talking about is because of the tread getting compressed. When the tire is stationary, then we have a contact pressure something like this because there are a number of treads. There is one tread that is getting compressed, another tread getting compressed a bit more, another tread much more, another tread slightly less and so on. So, number of treads are involved at various compressive positions and hence we have a contact pressure like that of the treads that are formed. On the other hand, let us now roll the tire. Now, when I roll the tire, let me follow a tread. So, that is for a static. So, I am just removing that. Let us now roll the tire. When I roll the tire, one tread or one block, that block is what we are going to follow, that block gets compressed, goes to a maximum compression. Then gets released. So, one block here, that block as I rotate the tire as the tire revolves goes into this position. So, same block goes into this position, maximum compression goes out and gets completely released. So, in other words, a block gets loaded like that and then gets unloaded. Now, how is that? It is going to be unloaded. It is going to be unloaded like this. So, unloaded like this. So, as the blocks gets loaded and unloaded, blocks gets loaded and unloaded, blocks gets loaded and unloaded, these blocks lose energy or hysteresis develops in these blocks. It is not only the blocks that gets compressed or loaded and unloaded, but the sides of the tire, they also go through the same thing. So, in other words, the sides of the tire gets also loaded and unloaded and so on. So, in other words, this loading and unloading cycle gives rise to this energy loss and that has to be accounted for by the wake. I am just repeating that so that you understand it and that is quite clear. Now, how does this loading and unloading cycle affects that contact patch in a very simple setting as we had seen? How does that gets affected? Because the loading cycle or loading path is different from the unloading path. How does that get affected? So, it was symmetric when it was stationary, that is fine, but when it gets loaded and unloaded, look at this carefully. For the same strain, in the unloading path, the stress is less. So, now we are talking about the pressure that is acting on the treads. Since, for loading and unloading, for loading and unloading, they are different, this curve cannot be symmetric because they are, both of them are not the same. So, they cannot, this guy is due to loading, this is due to unloading. So, they cannot be symmetric because I am following the same tread which is going through the cycle, so it cannot be the same. So, how it should be? This has to be a different curve, this has to be a different curve. So, the curve actually shifts and becomes like this. The curve actually shifts and becomes something like this because it is, the loading curves are different from unloading curve. The curve, you know, the symmetry is lost, becomes something like this. If I now say that the reaction force in order to support, there is not a very correct picture. That is why I introduced this inflation pressure. Keep that in mind. We will come back to this topic again. Not a very correct picture. We are going to see very interesting things, how inflation pressure is going to act and how actually the tire carries a load. We are going to get to details there. So, we will come to that a bit later, but let us now understand this from a different angle and give an explanation only to the rolling resistance. We will refine it as we go along. So, if this is the load that is acting on the tire, then the load is now equilibrated from the ground or in other words, that is the load that is going to act, which opposes the weight. Now, since this symmetric distribution is affected, what will be my resultant force due to this contact with the ground? The resultant force which is developed due to this compression which opposes the load that is on the tire would now get displaced and hence actually instead of acting right at the center, the load now acts away from the center and that is how the load acts. When it acts away from the center, then if I now look at that load, with respect to this center, not only I am going to equilibrate this load with this force, but I am also creating an additional effect correct. So, what is that additional effect? That will be a torque, that will be acting or a moment that will be acting like that right. Watch carefully that the moment is now going to oppose the motion of the tire. So, there is an opposing force or opposing moment that is acting. Now, I do not want to put that moment here. I know that the moment opposes the motion. So, I just want to replace this moment by means of a force that is acting here because that will oppose the motion of the vehicle. So, I replace this moment which in reality exists because of this co-elasticity by a force here and call this as rolling resistance force and say that this force, rolling resistance force creates the same moment which opposes in other words, F r into r is equal to this into this. We will give names to that in a minute. So, first let us understand the philosophy of development of a rolling resistance force. So, the philosophy of this rolling resistance force to summarize is the viscoelastic behavior of the elastomer which means that there is a loss of energy, which means that the symmetric contact pressure distribution when it is stationary gets affected or in other words it becomes skewed and the skewed distribution produces a force, normal force which not only opposes or not only supports the vehicle or the tire, but also creates a moment which opposes the motion and the opposing moment or motion or torque is now also depicted as a force which opposes the force. Motion of the vehicle or the tire and we call that as the rolling resistance force. So, that is why we have a rolling resistance force. The rolling resistance force, of course you can see this very clearly rolling resistance force since it comes out of a moment which supports the weight W. So, this force has to be proportional to W. So, we usually write the rolling resistance force to be a rolling resistance coefficient multiplied by W, multiplied by W. Obviously, the rolling resistance opposes the vehicle motion and hence is not within quotes a good force. It is not eating us to travel. Actually it is opposing you. Since it is opposing you or opposing the motion of the vehicle we consume energy because I have to overcome that like you have the aerodynamic forces, we have rolling resistance forces which opposes the motion. Interestingly note that when the vehicle breaks, this rolling resistance force would act in the same direction as that of the braking force which is now going to flip and act from the other direction. So, rolling resistance force aids in braking and opposes traction. So, the first thing you would tell that why not I completely reduce rolling resistance, go to zero is it possible? How low you can go? There are lot of issues. We will come to that later when we talk about time mechanics. So, first things first. So, that is the rolling resistance force which is written in terms of a rolling resistance coefficient and W. Our next step is to find out WF and WR. And WF determined by taking a moment about the point A and WR determined by taking a moment about the point B. So, on one hand we have WF into L is equal to on the other hand you are going to write down the moment due to the forces. So, you know this very well. So, WF into L is the clockwise direction. So, accordingly put the forces in the moment rather the moment due to the forces put the signs properly and we will see how we end up with this equation in the next class. We are going to make some assumptions with respect to this heights. We would see that usually in a passenger car these heights are almost the same and we will make an assumption that HA is equal to H is equal to HD. That makes our life simple. One of the things which is obvious which all of us experience which you would immediately notice is that WF and WR is going to get affected when a vehicle is accelerating or in other words that is what is called as a load transfer.  In other words there is a load transfer to the axles as well. It has a very interesting effect. So, we will write down this equation. We will find out WF and WR then we will look at traction and braking and so on. We will stop here and we will continue in the next class.


Hello boys and girls in today's video. We finish cleaning the heads and Lap the valves Enjoy Guys, so you saw me clean the heads lap the heads clean the block It's a lot of clean clean clean We clean the valves Now what I did was I know some of you may maybe against it Or simply may not know but I know I understand you got to be very careful doing any of this what I just did You know especially cleaning the valves now I used this steel wire wheel and this brass wire wheel Now I didn't I the intake ones the bigger ones. I only cleaned the faces of it, okay? Did not even lap Where they meet with the head, but the exhaust ones I use the steel to clean the top and Then the brass to clean The underneath here But what you got to be careful about is This area from here to here where it where this travels inside the head Inside the valve seals a little scratch here. This works like your lifters or your even your piston inside cylinder walls The these wheels wear out So you got to be careful Not to damage this area same thing when you lap it you want to make sure this is clean The inside of the head is clean when you put it back in It to spin it You know with the suction cup wipe it off if it's If it seems like it's not going in or something is in the way take it off. Don't push it It's it should almost drop on its own make sure your oil this lubricated with WD-40 or oil whatever oil is cheaper, you know When you when you before you turn it okay, it's got to go in easy. See I didn't lap The intake ones only the exhaust they came out pretty good This Was very minor. This was like kind of a refresh Okay, if this was in any worst state, then I would just give it to a shop for them to relap it and Lash it or relash it whatever readjust it That's why that's why I measure the lash before I even took them out Some of them are a bit too loose by a thousand Maybe thousand and a half I'm gonna check them again once after the lapping that I just did so they're going to the shop for decking anyways and cleaning What I wonder if you do these areas here still our TV goes back on here So they just all these got was just a light very light 2000 cent paper you got to remember you're gonna go off take off any really any material I just want to clean it off Because the cams spin here if you take any material off then these will become little you know slightly Eggie shaped instead of round When when they go back in same thing when you're cleaning inside here. You saw me clean the passages the runners With a steel brush careful not to hit the seat the valve seat or when you Same thing when you push when you put these back they don't go just almost just drop in there is dirt here they turn The lifters they turn inside here. That's got to be super clean also clean where the intake manifold goes This I had a kind of a hard time scraping off the old gasket with a Razor blade you go on whenever you're gonna use a razor blade Careful a lot of people say don't use a razor razor blade, but if you know what you're doing You know use it as you can see I didn't scratch The surface at all if you're careful you can do anything Same thing with the exhaust side also cleaned up the Thermostat housing and I made a mistake. This is actually not my block. I took these guide pins out For no reason I will really I just wanted to Lightly clean this these surfaces here So same thing with these surfaces here where the two blocks come together You only want to clean this area. You don't want to take any material off Because same story like with the camshafts these Where the crankshaft drops in They need to stay around if you take any material off These will become an X shaped instead of a circle so these pins took them off thinking I'm gonna Just buy new ones and put them in put them back in right well I first of all I destroyed them Taking them off. They just didn't want to because they were rusted inside and had dirt here And then you know all around and inside especially inside. I thought I'll just get new ones Just for the sake of it Well, they're not available. They only come with the block. So I call the dealer. I take them off, right? I call the dealer this guy It's it turned out that he didn't know what I was talking about. I was Pretty clear on it what I need. You know the two guide pins For the blocks to come together. You know when you split the block You got those two dowel pins or guide pins. That's what I need. Yeah I said, yeah, I got them, you know, three days. It'll be here, you know, two bucks each or whatever, right? You know cool, whatever So I go there after the three days. I Also ordered some other stuff He ordered me the pins that go from the block to the transmission I'm like, you know really dude So we're looking we're going through the pictures with the parts guy Can't can't seem to even find the part number for those pins and I go over to this mechanic which was standing close by to us and You know wave him over a man. Can you help us out? Can you let this parts guy know? You know what I'm talking about because he doesn't know so the three of us are looking at the Pictures here and you know, it turns out they're not available and this mechanic guy. He's like, hey, you know, we got a block Sitting here. We just took it out. This guy had a rod knock in an 08 08 WRX If you can split the block here and you take the pins, you know, you're you're welcome to I'm like, yeah, man If you let me borrow your tools, I'll do it, you know, and then the parts guy Chimes in and he says you got to make sure John is okay with it. So the mechanic left five minutes Comes back. He's like, you know, John's okay with it. Whoever John, maybe So I'm like cool, man, let me pay for this and I'll be there.  He's like, no, just take the whole thing Like really I can take the whole block. So this was a complete block, but no, it was shut They had a rod knock number four, I believe and The crank a beautiful crank destroy well not destroy I can still use it but starting from about mid of 08 Subaru started making nitrated hardened crankshafts and that's what What this blackhead inside but since it had a rod knock, you know, where the rat sits on the crank That the only that one was destroyed. I'm not sure what to call that. You know rounded area where the Rad sits as the crank turns that was destroyed Everything else was like almost like new or you just need it polishing after over a hundred thousand miles I can still use the crank in the future if I You know take some material off, but that will take the hardened material off. It will become like my crankshaft right now, you know minus Is all it needs is polishing but the nitrated would be a nice Upgrade as well for durability the hardened Metal would be nice. So anyways I'm taking that new new old from the WRX black with the pins back to the machine shop the heads also a new flywheel the the factory pulley and The factory rods. I'm keeping the rods They are forged after all they can take For for up to maybe 450 horsepower to the wheels. All that is gonna get Balanced the black is gonna get checked and cleaned the heads are gonna get checked decked and cleaned and Yep, that is it for now. Here. This is your bumper bumper beam here had a little bit of rust here Cleaned it off painted it took the AC system off As you can see the condenser is gone The lines AC lines are gone. All that's left is The expansion valve That's gonna stay. I'm gonna block it somewhat. I Filed down whatever I destroyed Taking the engine off Remember it was stuck on this pin here. I'm gonna put anti-seize Unhear So this is this is ready to go All right guys, that is it for now Not sure what's next. I'll just wait till everything comes back from the shop From the machine shop more repair videos soon to come Thanks for watching and I'll see you soon