Comment on 28-pound electric motor delivers 1000 horsepower

rekabis@lemmy.ca ⁨5⁩ ⁨days⁩ ago

• brucethemoose@lemmy.world ⁨5⁩ ⁨days⁩ ago

  That’s how EVs started! Sorta.

  But it’s impractical.

  • It increases unsprung weight, e.g. weight not cushioned by suspension. Bad for ride/handling/steering feel.

  • All that vibration is HARD on the motor. Read: unreliable.

  • Motor is more exposed to temperature/dust. Again, reliability.

  In reality, a decent suspension needs a lot of room under the body anyway. An axle to get the motor in the body is dirt cheap on the rear, and still pretty cheap on the front, and you could just mount this thing sideways to make it flat…

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• Canopyflyer@lemmy.world ⁨5⁩ ⁨days⁩ ago

  That would be a lot of unsprung weight.

  Handling and ride quality are dramatically and negatively impacted by every bit of weight that is not held up by the suspension. That’s why higher performance cars will have lightweight wheels. Rather than steel wheels you see on lower performance cars.

  It’s better to just put all the heavy drive components inboard on the chassis and run drive shafts to the wheels.

  You see motors in the hubs of bicycles, because they really don’t go that fast. So even if the bike has a suspension, it’s not that big of a deal. Motorcycles on the other hand would need to keep any heavy parts inboard.

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  • boonhet@sopuli.xyz ⁨4⁩ ⁨days⁩ ago

    Steel wheels haven’t been common on anything but really cheap cars for a few decades now, but in general your point holds true. There’s heavier and lighter alloy wheels out there.

    Still, these could be just tiny motors connected to the wheels via a short shaft on the rear especially. Instead of the huge monstrosities most EVs currently seem to use which are huge, as they also include gearing and such. Still leaves more space for battery without having to go unsprung with hub motors.

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• brucethemoose@lemmy.world ⁨5⁩ ⁨days⁩ ago

  PS

  One issue I hadn’t thought of is putting traditional brakes (which generate a ton of heat) right next to the motors. Again, we’re just asking for mechanical issues here, and we’re ballooning unsprung mass to mitigate it, especially in heavier cars that take a lot to stop.

  The entire floor pan could just be one thin battery, and everything above it could be passenger and storage space.

  This seems like a minor thing, but the control electronics for the motors takes up a nontrivial amount of space. So do “traditional” subsystems like hydraulics, climate control, or an old fashioned car battery (which often exists in parallel to the EV drivetrain).

  Theres also safety to consider. A traditional sedan “hood,” even a small one, is easier on standing pedestrians, so it hits their legs and they flop on top, instead of slamming them like a wall (as a bus/truck front would).

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• Resonosity@lemmy.dbzer0.com ⁨5⁩ ⁨days⁩ ago

  Aptera wanted to do this with their flagship Solar Electric Vehicle (SEV).

  IIRC, they switched to an outwheel motor because of the weight the inwheel motors added to the wheels. Could be wrong tho

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  • SaveTheTuaHawk@lemmy.ca ⁨5⁩ ⁨days⁩ ago

    Aptera

    LOL. Coming soon…since 2009

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    • Resonosity@lemmy.dbzer0.com ⁨5⁩ ⁨days⁩ ago

      For real lmao

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• lemming741@lemmy.world ⁨5⁩ ⁨days⁩ ago

  Hub motors are a party trick. They will never reach mass market.

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  • avidamoeba@lemmy.ca ⁨5⁩ ⁨days⁩ ago

    They work well on bikes. I could appreciate 1000bhp hub on my 12kg touring bike. 🤭

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    • lemming741@lemmy.world ⁨5⁩ ⁨days⁩ ago

      I agree, they are good for minimally suspended low speed personal transport.

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  • EtzBetz@feddit.org ⁨5⁩ ⁨days⁩ ago

    German company DeepDrive has some kinda promising tech. And the ID.Polo seems to be said to have hub motors.

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    • lemming741@lemmy.world ⁨5⁩ ⁨days⁩ ago

      Not even the concept had hub motors.
      www.autoexpress.co.uk/news/volkswagen-id-polo
      electricarworld.com/volkswagen-polo-makes-a-comeb…
      auto.hindustantimes.com/…/volkswagen-id-polo-gti-…

      Limited slip differential? Can’t do that with hub motors. …com.ph/…/volkswagen-id-polo-prototype-a5100-2025…

      If you have different information about a production car, please share it. The theoretical concept ID.2 R may use hub motors but that is vaporware at this point.

      Image

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      • EtzBetz@feddit.org ⁨5⁩ ⁨days⁩ ago

        I only have german articles. I only heard it in the video source below, and they sadly don’t really say how the normal problems with hub motors would be solved even though they have a section for it in the video.

        electrive.net/…/vw-soll-neues-topmodell-id-2-r-mi…

        youtu.be/R3Sok4ZbUyo

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  • boonhet@sopuli.xyz ⁨4⁩ ⁨days⁩ ago

    They might work in the rear if used instead of rear brakes. Rears do far less work anyway and brakes are heavy. Powerful electric motors can do a lot of regen, similarly assisting the front brakes.

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  • SaveTheTuaHawk@lemmy.ca ⁨5⁩ ⁨days⁩ ago

    Renault 5 RS Turbo has hub motors, Nostradamus.

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    • lemming741@lemmy.world ⁨5⁩ ⁨days⁩ ago

      mass market There’ll be 1,980 of these built

      That car is the definition of a party trick. You proved my point, so thank you.

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      • SaveTheTuaHawk@lemmy.ca ⁨5⁩ ⁨days⁩ ago

        Right, because 2000 of something is not mass production.

        And here is a source in China definitely not making >20 hub motors for cars, scooters, etc.

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    • brucethemoose@lemmy.world ⁨5⁩ ⁨days⁩ ago

      Renault 5 RS Turbo

      That’s because its a limited run show car. Its not meant to be practical.

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  • kylian0087@lemmy.dbzer0.com ⁨5⁩ ⁨days⁩ ago

    Imagine on a motorcycle… Probably nonstop wheely 🤣

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    • KneeTitts@lemmy.world ⁨5⁩ ⁨days⁩ ago

      Probably nonstop wheely

      uni-motorcycle

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    • lemming741@lemmy.world ⁨5⁩ ⁨days⁩ ago

      They make sense for scooters, bikes, and other low speed or two wheel personal transport. For anything with an actual suspension (designed for a highway) there is just too much competition for space with brakes and suspension linkage. The unsprung weight, exposed high voltage cabling subject to road debris and accidents are problems too. And what to do hub motors really gain you?

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      • SaveTheTuaHawk@lemmy.ca ⁨5⁩ ⁨days⁩ ago

        Less weight, less parts, 4WD, 4W traction control, more cabin space because no driveshafts.

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      • eleitl@lemmy.zip ⁨5⁩ ⁨days⁩ ago

        Simplicity, no transmission. As to unsprung weight, designs like these have a ridiculous power density, so add only very little. Advanced suspensions are active anyway, so just part of the wheel robot.

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• Nastybutler@lemmy.world ⁨5⁩ ⁨days⁩ ago

  Except for the fact that that much power would need massive batteries. So your thin small battery would be dead the first time you mashed the peddle to the floor

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  • IAmNorRealTakeYourMeds@lemmy.world ⁨5⁩ ⁨days⁩ ago

    forgot the part where they were excited to put the batteries on the tire

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• vithigar@lemmy.ca ⁨5⁩ ⁨days⁩ ago

  This is already pretty close to how many EVs are designed.

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