Elon Musk started a price war that Tesla can't win

[donquixote99]

OK, I'll buy 40,000 rpm for a turbine, but geared way down for the rotors. You were not seeing (and in particular not hearing) a thing with supersonic rotors.

[BigElCat]

Originally Posted by donquixote99

OK, I'll buy 40,000 rpm for a turbine, but geared way down for the rotors. You were not seeing (and in particular not hearing) a thing with supersonic rotors.

It apparently had four electric motors to spin the props, on arms that were proportionally shorter than small scale quad copters.

The body (I guess you'd call it a fuselage) looked like this, except it had no side pods, only landings skids like helicopter. No windows, just four port holes in the lower front facing skin.

polar-lights_star-trek-galileo-shuttle_01.jpg

The rotors would have been spinning with the tips, or hoops, going at sub-sonic speeds.

I brought it up, because it must have had some kind of ultra light weight, high discharge, battery with pretty good range. It wasn't designed for forward speed, or a low drag co-efficient.

[donquixote99]

Originally Posted by BigElCat

It apparently had four electric motors to spin the props, on arms that were proportionally shorter than small scale quad copters.

The body (I guess you'd call it a fuselage) looked like this, except it had no side pods, only landings skids like helicopter. No windows, just four port holes in the lower front facing skin.

Attachment 4245



The rotors would have been spinning with the tips, or hoops, going at sub-sonic speeds.

I brought it up, because it must have had some kind of ultra light weight, high discharge, battery with pretty good range. It wasn't designed for forward speed, or a low drag co-efficient.

OK. what had me going is that 40,000 rpm number. What you describe now would have nothing going any where near 40,000 rom.

[finnbow]

Tesla says profits fell 55 percent in the first quarter to $1.13 billion while revenue declined 9 percent.

https://www.washingtonpost.com/techn...nings-outlook/

[BigElCat]

Originally Posted by donquixote99

OK. what had me going is that 40,000 rpm number. What you describe now would have nothing going any where near 40,000 rom.

Bah ! One has to take what I say with a 'grain of salt'.

When folks talk about money, 40M is $40,000, not 40 million. (and this supports my argument somehow)

Guess I was talkin' about metric RPM. It made a 'whirr' noise. (grin) Minimal down draft, lots of lift.

[Rajoo]

Originally Posted by BigElCat

Bah ! One has to take what I say with a 'grain of salt'.

When folks talk about money, 40M is $40,000, not 40 million. (and this supports my argument somehow)

Guess I was talkin' about metric RPM. It made a 'whirr' noise. (grin) Minimal down draft, lots of lift.

Everywhere I looked, $40M is 40 Million dollars. If its $40,000 usually designated as $40K.

Also as to high rpm motors, we have a CNC that is capable of 40,000 rpm but we don't run it over 15K rpm because, at higher rpm's the torque (force required to shear metal) is greatly diminished. Also familiar with 80K rpm motors, but they are small and usually pneumatic because an air blanket is used as a bearing (no metal to metal contact and the air needs to be expunged anyway).

As to rotors capable of lift, making a bearing to handle the thrust and vibration will be a far bigger challenge.

[donquixote99]

Originally Posted by Rajoo

Everywhere I looked, $40M is 40 Million dollars. If its $40,000 usually designated as $40K.

Also as to high rpm motors, we have a CNC that is capable of 40,000 rpm but we don't run it over 15K rpm because, at higher rpm's the torque (force required to shear metal) is greatly diminished. Also familiar with 80K rpm motors, but they are small and usually pneumatic because an air blanket is used as a bearing (no metal to metal contact and the air needs to be expunged anyway).

As to rotors capable of lift, making a bearing to handle the thrust and vibration will be a far bigger challenge.

Apropos of the forums audio roots, has anyone ever made a turntable with a pneumatic motor? Ir occurred to me a long time ago that that approach might offer opportunities to isolate the device fron the tiniest of vibrations.

[Rajoo]

Originally Posted by donquixote99

Apropos of the forums audio roots, has anyone ever made a turntable with a pneumatic motor? Ir occurred to me a long time ago that that approach might offer opportunities to isolate the device fron the tiniest of vibrations.

Glad you asked and here is one, but way out of my league at $8K+ but really not that pricey as high end TT's go. I heard a $50K table once, I bought a pair of ProAc speakers from him and the wood work (plinth) alone was simply out of this world, perhaps one of a kind.

I had borrowed a $15K VPI Avenger ($26K now) for a long time (years) from a close friend, so this sounds downright reasonable.

It does not take a lot of air flow to make an air bearing as long as the mass is low enough to float, but the machining can be a nightmare.

https://holbo.si/

https://theaudiophileman.com/holbo-a...system-review/

[BigElCat]

FWIW...M is the Roman numeral for 1,000.

Financiers use MM to denote a million, or so I was told.

[Rajoo]

Originally Posted by BigElCat

FWIW...M is the Roman numeral for 1,000.

Financiers use MM to denote a million, or so I was told.

I do remember that in doing budgets back in the 70's and 80's which was before advent of PC's. Sometime later it went Metric (grin). K for Kilo (thousand) and M for Mega (Million).