feddit.org

0 points

14 days ago

I enjoy your calmly delivered flimflam.

Such as: having direct visibility into the proprietary developments that are negative to the company in its infancy.

That musky actually understands why use of a ‘bigger motor’ would solve the problems associated with gearboxes. For that matter, that you understand the technical choices made in the matter are funny as well.

What kind of motors were picked, and why? I further love that your messiah still went for a gearbox design in the earlier model s that failed very very loudly as they drive around.

You’ve helped further cement how embarrassing his engineering skills are to professional mechanical engineers in the midst of your proselytizing.

I’d say Tesla and other companies are succeeding in spite of, not because of, musky. Cheerio.

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SirEDCaLot@lemmy.today

0 points

11 days ago

“It is the mark of an educated mind to be able to entertain a thought without accepting it.” --Aristotle

You’ve proven yourself uneducated and closed-minded. I’m not saying that because we disagree, I’m saying that because you are asserting a position without evidence and an ad hominem attack (making fun of me personally rather than attacking the position I have).

For example- a bigger motor solves the problem of shifting by removing the shifter. Eberhard was hung up on the shifting problem for over a year, let that issue stall Tesla’s development. You don’t have to be an engineering genius or pro-Musk to read the history on that. And I was literally watching it happen- reading the Tesla blog where they were talking about the engineering problems with making the gearbox shift at high RPM and switching from one design to another, one supplier to another, etc.

You don’t have to be a professional engineer or pro-Musk to understand the logic behind ‘the best part is no part’.

And you don’t have to be an auto expert or pro-Musk to see that most automakers were stuck in a constant ‘10 years away’ cycle of EVs. You just have to follow a little history or be alive longer than Tesla (that’s not an age insult, just pointing out that for automakers EVs were essentially a pipe dream. For reference watch “Who killed the electric car?”).

I’d encourage you to open your mind, set aside your personal political biases and recognize that there are few absolute black and white / angels or devils in the world. Good people are imperfect, bad people sometimes do good things. Taking an ‘absolutist’ view on almost any issue leaves you blind to the nuance of the world and that leaves you uninformed.

Best of luck.

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1 point

11 days ago

Yawn. Hello ad hominem, early on. Lots of unnecessary verbiage.

The rest of your argument is both trite & false, and again reveals a lack of engineering prowess/understanding. It’s not always intuitive, so I don’t blame you much. Quick example: gears add contact friction, but also significantly reduce bearing loads on the motors, among other things. You trade some efficiency for better lifetimes on the parts experiencing the most pressure. Further, Teslas still have a gearbox, and even as a single stage system, they still experience failures. “No part” eh?

If there was anything to learn from reading a carefully manicured blog where honesty isn’t guaranteed, it’s that there wasn’t enough of a commitment to getting it right, iterating takes time, which is still why I won’t buy one of those styrofoam-padded shitboxes. Still buying an EV, just one that was actually well designed.

That you feel attacked by my laughing at your conclusions, well… Cry about it.

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SirEDCaLot@lemmy.today

0 points

11 days ago

I don’t feel attacked. You’re just another internet person. I’m concerned that there’s an awful lot of people like you these days, who take some position and then mock anyone who disagrees. It shows a serious lack of critical thinking.

Quick example: gears add contact friction, but also significantly reduce bearing loads on the motors, among other things. You trade some efficiency for better lifetimes on the parts experiencing the most pressure.

Quite true. Electric motors want high RPM, so you NEED a reduction gear to turn a motor’s high-RPM output into a car’s low-RPM wheel rotation speed.

But the problem isn’t gears, the problem is SHIFTING. At highway speed an electric motor can be going at 15,000-20,000 RPM and is quite happy in that situation. A gearbox is too. But SHIFTING at that speed, even with a synchromesh, puts extreme stress on the system. THAT is the problem. Eberhard was focused on getting shifting to work, and for over a year was trying various designs of two-speed shifting gearbox from various manufacturers. This wasn’t something that existed, that anybody had bothered to design. And Tesla had working specimens, they just didn’t last long at all because the extreme stress of shifting at highway speed would shred the gears. Eberhard was letting that technical problem hold up delivery of the car.

Elon then said ‘scrap the shifting, put a simple one speed reduction gear and increase the motor torque to provide whatever we lose by not having a 1st gear’. And I’d say that is objectively the correct answer, proven by the fact that now EVERY EV from EVERY automaker uses that design.

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1 point

11 days ago

Oh, just lol. I can see the nuances of the engineering choices aren’t getting through here.

That very choice is a critical part of why there aren’t many cheap EVs on the market. If you’ll recall, Eberhard was trying to keep costs down so that ordinary folks could afford the vehicle. Smaller motor plus gearbox costs less and reduces other costs as well. Elon changed the engineering goals, forcing the roadster to be priced yet higher.

A large, custom motor “solves” the problem inelegantly by replacing an undersized mallet with a sledge, as you’d expect from a moron. Correspondingly larger IGBTs, larger switching losses, more battery capacity lost to needing to parallel vs series for feeding the larger motor a lot of current. There were and yet remain many downstream negatives to that decision.

As for the rest of the market following, why are you surprised that the same market which kept saying “10yrs away” also couldn’t be imaginative enough to innovate?

It’s obvious you don’t want to shift from your position either, the funny bit is that at least one of us here has evaluated merits vs problems with any technical background. Keep on drinking that corporate Kool aid.

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SirEDCaLot@lemmy.today

1 point

11 days ago

A larger motor solves the problem of mechanical wear by replacing mechanical components with solid state ones. Yes you need bigger IGBTs, bigger current handling capacity starting at the cell level, parts must be stronger to handle more torque, etc. There are downsides.

But in almost all engineering situations, it’s well understood that replacing mechanical components with solid state ones is almost always the right call and leads to better reliability / durability. I can think of MANY situations where the evolution of a product went from mechanical to solid state (with quality and reliability increasing as a result), I can’t think of any situations where a solid state system was replaced with a mechanical system and it ended up being better or cheaper.

My mind is open though, feel free to provide some examples.

If you’ll recall, Eberhard was trying to keep costs down so that ordinary folks could afford the vehicle.

What I recall was the plan from the beginning was always that Roadster would be an expensive ~$150k+ rich people toy that would finance development of the $80k luxury car that would finance development of the $30k car for everyone. I don’t remember anyone talking about ‘ordinary folks’ driving a Roadster.

I remember many journalists were allowed to drive early versions of the car, but locked in 2nd gear.

If you want to argue that there was a negative trickle down effect- that starting with Roadster, sizing the motor and power handling for extreme accel led to higher costs, it’s a valid argument but I personally disagree.
I think a more valid argument is that putting such extreme accel in a car set an extremely high standard and it became expected that an EV would be quick off the line. Whereas, an EV that has ‘normal gas engine accel’ (say 0-60 in 6-8 seconds) could use smaller motors, smaller IGBTs, smaller wiring, etc and thus cost less but wouldn’t sell as well since Tesla set the bar so high. That’s a valid argument.
Personally I don’t agree- I drive a Tesla Model Y long range, and the rapid acceleration is one of my favorite features of the car. Other than just being fun, it means there’s never a question of ‘can I accelerate fast enough to turn in front of that guy?’ or ‘do I have space to pass this person?’.

I also note that mainstream automakers were focused on large format pouch cells for their battery packs, which suffered issues of thermal expansion and containing a runaway reaction. Tesla used a couple crates of 18650s and coddled them, and in time ‘large number of small cells’ became the industry standard.

I also note that other automakers are now talking about ‘shifting’ EVs but they’re simulating the effect with motor control tricks and a speaker that plays fake engine noise. You could say big auto had no imagination 10-20 years ago, but now EVs are going mainstream and that excuse no longer holds up. If an automaker is going to the trouble of making a fake electronic ‘transmission’, why wouldn’t they just put a real transmission and a smaller motor / smaller power handling system?
I’d argue because even without a need for extreme accel, the big mechanical transmission costs more in cost and weight than the larger motor and power system would.

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1 point

11 days ago

No, it doesn’t solve the wear problem, that’s precisely my point. It moves it, and at a monetary cost.

Easy example of adding complexity to help meet a goal, geared turbofan engines. Simplicity and reduced short term cost? Antithetical. Long term costs thanks to efficiency savings? In spades.

I still see parroting of seeming truisms versus actual understanding on choices made, based on changes observed since the 70s onward. “Solid state always beats mechanical”, for instance, something that _seemed_obvious in the 70s and 80s. This makes you out to be around what, 55 is my guess.

The tribal knowledge of implementation details have changed since the solid state revolution, some applications of solid state are still past the edge of solid state capabilities if your goal is cost reduction. That was Eberhard’s intent, and what a geared motor would help solve, never mind the expected initially high costs.

How/what kind of motor is built dictates its favored unloaded RPM, haven’t you seen exposed A/C motors spinning fans for e.g. pumps or Aircon condensors? 20k rpm as an argument?? Jesus. I read between the lines and see your actual understanding of the matters.

So listen, I’m not interested in converting a zealot. I personally also believe solid state is the way to go for controls and other parts of a system, but the difference between a junior and experienced engineer when it comes to production at international consumption levels is knowing what tools are appropriate, and where, in that system. A lot of the rest of your argument text is a red herring, I encourage you to reread it and discard it as I have.

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