An oversimplification has been done on the cost to strength issue of Mg: strong lightweight materials have higher structural bracing if higher stresses are to be applied. If not, then there are no savings. The relationship between material strength and volume usage (cost) is not linear.

@@ptviwatcherI took that into account. That's why I said I could do another video entirely on material properties.

​@@thelimitingfactorawesome, thanks for the feedback!

@thelimitingfactor Do you know who I can contact regarding my availability of magnesium chips? I would like to part of this process and I have a good supply of chips.

First comment at: 20.49. Weigth of the wheels is not very important to the efficiency of the Electric vehicle based on my calculations and tests. If and when I get rid of 24kg of rotating weigth in Model Y. Energy savings in steady state speed is only 0,2% from what comes from weigth loss. What matters to consumption is the Aerodynamics and rolling resistance of the tires. 24kg rotating wheels and tires weigth loss impacts to acceleration is 3% in Model Y and little less for braking. Impact to drivability of the vehicle will be bigger. Where the energy savings in EVs wheels and tires can come from can be seen in this video: kzfaq.info/get/bejne/qbiqlLyn072Weok.htmlsi=-SSmFESp02tdgK4u you can find more videos on the topic on the channel. Here I am developing new wheels and tires to evs and this thixomolded magnesium is the top choice for material at the moment. So thanks for the videos you make on the topic. My current design is 8x18 and weigth under 7 kg if made from 6061-T6. Your questions rack at the pinned comment: 1) I have tested many wheels and a lot of videos on my channel. Its difficult to measure impact of only wheel weigth savings on road even to professional who has done it 15 years or so. Needs perfect conditions and good test methology. If you need help for the setup send me message and I can tell how I would do it depending where you live etc. 2) EV gather some of the potential energy back so savings are even less than in petrol car what comes to weigth savings. 5) if you want to test the weigth savings on wheels just pick a EV where you can fit steel wheels and wheelcovers. Then just add a 10mm thick layer of steel to the wheel to get enoguh weigth savings that can be measured. I would recommend that you actually put there 50kg extra to get so much weigth difference that you have any chance to measure it on the road. For city driving maybe 25kg is enough. Put ithe weigth on the barrel to get bigger impact on rotating weigths I could do also this test I have 2 sets of 195/60R18 tires, but sadly at the moment no steel wheels in that size. maybe I could use the 17" wheels and buy a second similar steel wheels that I have at the moment. But in short you dont need to buy any mag wheels to test weigth differences in wheels. It goes both ways in general the same way how it handles in the car. Of course it goes much worse when adding weigth compared to current desing. But on the other hand if go smaller diameter wheels and tires than oem you already have lighter basic set so impact is not so big. 7) I would like to go magnesium design because of the noise absorbing features of the magnesium. I already have the lightest design on chosen material. If anyone is interested to help me out I am trying to build a team to battle the challenges of a startup. Special needs will be in the sales and marketing side of things. If you are a manufacturer that already has purchased a magnesium thixomolding machine that can make parts that are under 10kg I think we should talk.

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You should check Dillon Loomis aka Electrified. He is calm and objective.

@@malax4013 Dillon's OK. Haven't seen his stuff in a while though. Don't know if he moved on to other things or the Algo doesn't send him my way anymore.

Dillon is reliably positive about everything Elon says and does. I agree he is calming. I disagree he is objective.

Agree!!!!

Thanks for watching! yes, it's exciting stuff 😁

Great way to put it! That's kind of what I'm going for

Does magnesium burn easily?

​@@jamesdallas1493aluminum actually burns easier than magnesium, but we add things to it to stop it from happening, this is already been proven to work just as well from magnesium

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Yep loved it. 🤠👍​@thelimitingfactor

I've made a pinned comment.

Tesla Plaid Channel has done extensive drag racing and shows significant improvements in quarter more times on lighter wheels.

@@jamesengland7461 Quarter mile is pure acceleration, of course you're going to see a big difference. we're talking about energy consumption in real world driving here. put another way, no one would load up their car with an additional 500 lbs of weight for drag racing, but tests done by Byorn Nyland (Teslabjorn) show that it almost doesn't matter for highway consumption.

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That's really great to hear! Thanks for sharing, I like insights like this

The best part is no part.

The best wheel is no wheel, The 2nd best wheel is an ultralight wheel

@dewiz9596 Oh definitely. You not only have to move the mass along, you have to spin it up! Therefore weight at the rim is more important at the hub.

porsche and other manufacturers have been making magnesium wheels for decades, offering carbon fiber seats, roof, hood...........

Dude! I just checked out the video that you linked - You're doing really great and thorough work, I love it 🔥 Are you on X? Because if you are, I'll repost some of your work and get some eyes on it. The type of testing and videos you do would be great for content there.

Love to hear it!

Glad to hear it Eduardo!

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They already do buy vehicles with magnesium castings in them. That is, it's pretty much pushing through an open door in the market. Yeah, it looks scary, but that doesn't stop people from carrying, for example, a phone in their pocket all day that could permanently disable and scar them if it explodes. At least with the Mg casting, it's all the plastic and batteries that will kill you before the magnesium even ignites.

Thanks man! 🤜🤛🤠

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Hey thanks man, suer thing! 🤠

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I enjoyed making this one 😊

Thanks man! Glad you enjoyed it. As for Al gigacastings - I've heard rumors that the limits are far beyound where we currently are. As for Mg thixo - it sounds like everyone is assuming that 20 kg shots is just the very beginning. That is, it doesn't sound like there's a physics limit that's been found yet...it's just a matter of engineering and the learning curve, step by step.

given the pressure required to make the castings larger with current machines and tesla basically maxing out the aluminum alloy design at this point, that seems challenging and very expensive. I think making the castings bigger would probably require looking into things like multi-point injection to reduce the travel distance and therefore the required pressure. I think another potential solution would be designing a few separate castings at the current size that socket together and are joined using a few large magnetic pulse welds.

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Excellent! Glad to hear it 🤠

It was covered in the last video briefly...the cycle time is the same as al gigacasting

Sure thing 😀

Where is the ore for titanium plentiful. The last I looked most titanium in industrial use goes to make white paint and it was sourced from sand mining which was very environmentally destructive and uncommon.🤔

Amen!

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I don't/didn't. I have a magical network of elves who's brains I pick 😁

If you're starting with a clean sheet design or a remodel you can.

Road wear is proportional to the *fourth* power of axle load. That makes cars negligible. Only trucks matter.

@@musaran2 Thanks for your comment. I looked up the fourth power of axle load and you are correct. This now has me wondering what proportion of road maintenance the heavy transport industry pays.

​@@markumbers5362That's a great question, we should find out

Amen!

You're most welcome! Thanks for the support.

Look closer at the spider charts. The information is on the screen.

@@thelimitingfactor thanks! I tent to listen to your videos as audio podcasts on the road. I’ll revisit!

OOoooh, I didn't think much about Spacex. Good point. The rockets will be primarily stainless steel due to their strength to weight ratio and thermal tolerances. So, I'm not sure where that Mg could be used except in like vehicles, satellites, doors assemblies, etc.

@@thelimitingfactor Good point, I'm learning about all of this now but it's a fun material science journey to be on.

The reason why it didn't take hold for the first 20 years it because it was under patent and Thixomat did a poor job of commercializing it. Check out the headline article on Light Metal Age today.

​@@thelimitingfactorThe patent issues in the light metal industry from the mid 1980s through to about 2010 has been a can of worms, however I doubt that is a factor that held back the adoption of thixomoulding. There are some definite theoretical advantages of thixomoulding over die casting so there may still be a bright future for the technology. The S&P global analysis does not appear to me to be of much value. Predicting the future prices of commodities is a game for the brave.

Fair enough, but you've effectively said nothing other than "I disagree, I'm cynical, and it's hard to predict the future" Great, but that doesn't add to the conversation and I haven't learned anything from this discourse.

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Stagnation fallacy

1) That was included in the analysis. If you take a close look at the spidercharts, both Mg and Al evolve from 2020 to 2030. That is, it's not a matter of fixation, it's a matter of keeping the video from being unwieldly and long winded. 2) Good point! But, manufacturers will have a choice of which allow they use for which application. So long as the cost and supply and right, they'll make the right choice for the use case (well, one should hope)

​@@thelimitingfactor Re 1: I understand that; I simply doubt that the research underlying that spiderchart was done by someone with a good combined grasp of industry trends, industrial engineering and the totality of highly relevant underlying physics/chemistry. Simply because those people are super rare (I'm certainly not one of them!), and people with a more narrow perspective also write reports. You're wading in deep waters where even thoroughly researched reports by respectable and competent institutions don't automatically have a high signal to noise ratio.

​@@sealpiercing8476 I would have to agree about the aluminum improvements possibly being understated. from what I understand one of the huge benefits of semi-solid casting is that it dramatically reduces hot cracking, which lets you use higher-performance heat-treatable aluminum alloys that otherwise could never make such a complex casting. there also is plenty of alloy development (and not just for toughness). For example, we're still working out how to make easier to process aluminum lithium alloys, which could noticeably reduce the density. There are also developments in aluminum foam production that could present significant weight savings, especially for energy absorption structures. aluminum foam could replace a lot of the big flat stuff like underbody and structural battery pack faces wholesale without needing to do casting at all since it's inherently stiff enough. I'm also realizing there's a material we missed completely that I've actually worked with. Fiber composites with thermoplastic resin. Dr. Yu here at Purdue's CMSC does a lot of work in modeling diecasting of short-fiber composites, and there are even a few car panel test parts hanging up in the lab, I think from a project with one of the big auto manufacturers a few years ago. "low quality" carbon fiber, let alone glass fiber, keeps getting cheaper and it still beats out aluminum or magnesium casting allows for strength and stiffness at magnesium density, so that could show some impressive results in the future. The other big development in thermoplastic resin fiber composites is die stamping (also being worked on here at Purdue). it cuts out a lot of the labor and capital required for traditional fiber composite manufacturing since it's fast and doesn't need an autoclave.

Already covered in the first video the series

Please direct to coverage thanks @@thelimitingfactor

found it thanks @@thelimitingfactor

I tried to put out a magnesium fire it's not worth the trouble

Likely different products with different use cases, properties, and cost structures. That is, much like there is no wonder battery, there is no wonder material. There are always first principles trade-offs. However, I don't know what those specific trade-offs are for carbon fiber. It's something I'd have to do a deep dive on.

@@thelimitingfactor ya true, Mg might have its niche...only worry I have for CF is that is breaks/brittle fracture...no smooth deformation, but the aerospace industry trusts it so it should be safe enough. Ya if you do a vid on this I'd look forward to seeing it.

Equal recyclability, but as I covered in the last video, there's just another step for thixo

That's just the cost of the cell and the battery pack and nothing else

Sure thing... Molten magnesium reacts with water, but that's really only an issue for the firefighters, and it's something they've been dealing with for about 100 years. Solid magnesium metal does have corrosion issues but... That's a solved problem. For references, check out the first video of the series.

I may do a video on that, but it'll be a while, in the meantime at 27:43 I included the title of a paper that covers this.

@@thelimitingfactor That would be great. There's lot of confusion about aluminium alloys not having fatigue limit (unlike steels). It be interesting to see the comparison and similarities between aluminium and magnesium alloys. It's probably more important in aerospace, but I guess if magnesium is gaining popularity aerospace industries will also be interested in lighter and cheaper materials and processes.

I covered that in the video, and joining materials with different galvanic properties is a solved problem. Tesla does it all the time.

He covered that at 19:00. Basically, different alloys of magnesium and coating can address this issue.

Planes have very different economics than vehicles, with different requirements, and use much more advanced alloys with different metal working techniques. That is, it's not in my wheelhouse. Glad you enjoyed the video! Lol, yes, carbon fibre wheels and forged mag wheels are very dear. $ Hoping that changes with thixo

Good point! Metal foam has porosity, lol

I would have to do a deep dive

This series is just focusing on automotive. Aeronautics is another kettle of fish.

I don't know how mag rims would do on a semi, but that's potentially a big opportunity. Each semi rim can weigh 50-80 pounds depending if it's aluminum or steel. 10 rims on the trick = potentially 150 to 300 pounds.

Since they would be making both the mag and al dies, I left it out. I wanted to make it like for like as possible for a given manufacturer. If it was non tesla, then they wouldn't make either die in house.

The other big question on hub motors is, even ignoring the weight, whether it's more reliable to transfer power to the wheel from a central motor via well proven CV joints and shafts or via electric wires, which have to flex to follow each movement of the suspension. Copper wiring particularly is very sensitive to this, to the point that the wires passing through the driver's door hinge on many cars will fatigue crack in less than a decade. The car's suspension will move through a lot more stress cycles per hour of use than the wiring through the car doors will ever see, so this issue might end up being surprisingly important. This is an issue that can be solved with good design (Or even by getting a bit weird - like using electrically conductive liquid down the brake lines to transmit power - but I would certainly prefer a CV joint or shaft failure to having 800 Volts ground itself to the body of the car or create a spark that ignites the vehicle (With a well designed electrical system it should cut the battery connection at the first spark/ground fault, but one of the issues that haunts electric cars is that a lot of the regulations they have to meet were not written with electric cars in mind, so cars that meet the regulations perfectly (Even those designed in good faith to do so) can still fail in unexpected ways. The ferocity of electric vehicle battery fires is probably the most shocking example.

You have no idea of the improvements in electric propulsion. Hub motors are a thing of the past.

@@tedmoss Lucid are getting about twice the power to weight of a Tesla motor from their motor design, so there's certainly room for optimisation, especially when you don't need 800 bhp. Most of the issues with hub motors are that they add unsprung weight, so a light hub motor combined with, say thixomoulded Al or Mg wheels to save more weight could give equivalent ride to conventional setups. The payback is the benefit of removing all requirements for drivetrain space from the interior of a car, so cars get smaller with the same interior space, or remain the same size and get more space. Provided the hub motor people don't do anything as stupid as putting the hub motors in a tricycle with a central rear wheel, which wastes all the potential extra interior space, like Aptera is doing (Or promising they're going to do if they ever get past the vapourware/hoovering up techbro investment capital stage).

Next video

I'm sure they already are looking into it, or at least aware of it. 100% sure

I explicitly said this was years away and it depended on magnesium scaling, and I'll cover that in the next video.

@@thelimitingfactor Yes you did. And I was left feeling that was a long lead time yet necessary component. As to the rest of my question(s)....?

Covered in my crashworthiness video. They use sacrificial extensions.

Correct, that's why I said that it would require another entire video to cover material properties. I deleted a full page of script just on buckling alone after I realized that it would turn the video into a >1 hour video.

@@thelimitingfactor I can see why that would happen. buckling isn't very intuitive if you haven't done any structural engineering (I just got my undergrad in aerospace engineering from Purdue), so I get why it wasn't included. A lot of the car, including a lot of the heavy energy-absorbing components, are stiffness-driven, not strength-driven, and some parts like paneling would probably use thinner metal if the tooling allowed. Given that, I think your strength only estimates probably undersell the potential weight savings with magnesium. On the other hand, as an engineer, I do appreciate conservative estimates.

If you look at the spider chart, you can see that the Al characteristics improve as well from 2020-2030...so yes

thixo welds better - less porosity

Almost all aluminum alloys contain magnesium

Thanks! The cautionary note was that I stated what the comparison was explicitly. And, I left everything on screen so people can make their own comparisons and come to their own conclusions. A good point on scrap, I did cover that in the last video but I could have touched on it again here

@@thelimitingfactor Ah. should watch again from the start when the series is complete. Memory is not what it used to be.

For a vehicle that wouldn't be necessary and what add cost

See the first video. No

Why does nobody read the pin comment 😂

There's crush cans at the front and rear. Those can just be unbolted and a new one bolted on. Any damage beyond that would normally be a write-off for any car, and the same is true with giga castings

@thelimitingfactor Yeah, I realise that officially, they are written off, but you can still weld in new parts. Can magnesium be welded?

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Depends for what

Sorry, didn't specify. I meant that since we're usingprogressively lighter casting metals, one day we could make car bodies out of lithium or hydrogen. Of course, we can't even make the latter yet. But do you know if it's possible to use lithium? I feel like it would be explosive, but then again I didn't imagine magnesium could be used either. @@thelimitingfactor