Re:The Death and Life of Helicopter Commuting [video]
by Alupis on Wednesday August 30, 2017 @05:53PM
(#15136396)
Just a note on your comparison - aviation engines/motors are not directly comparable to land vehicle engines/motors. They have different expected duty cycles[1][2] and thus, are designed quite differently.
I believe the engines in an Apache are jet turbines, which may also not be directly comparable, but that's only a guess. They are also "war machines", and likely are built to tolerate abuses Tesla cannot imagine and do not design for (my assumption here is that is what adds quite a bit of weight to the Apache engines).
All this is to say the obvious, one could not simply take a Tesla electric motor and install it in an aircraft, expecting good things.
Things may eventually change, and ultimately you may be right - I just don't want to put that much faith, yet, into this idea.
[1] https://aviation.stackexchange.com/questions/11527/what-are-...
This one had me wondering, especially since one of the reasons that model quadcopters even exist is because of breakthroughs in brushless motors which have good power to weight ratios for things that fly. So trying to compare a state of the art helicopter engine and a state of the art brushless motor lead me down this path ...
It is notoriously difficult to get details out of Tesla but according to this: https://chargedevs.com/newswire/elon-musk-cooling-not-power-... the Model S electric motor is 362 bhp at a weight of 70 lbs (5.2 HP/lb), and according to this: https://www.geaviation.com/sites/default/files/datasheet-T70... the engine used in the AH-64 Apache is 1662 shp at a weight of 458 lbs (3.62 HP/lb).
The point about cooling is well taken (Elon mentions it as a challenge) however in both model airplanes and quadcopters the motor typically is mount directly under the rotor so that not only does the prop wash provide the lift for the craft, it provides a lot of cooling for the motor driving it.
Again, not saying that you're wrong or that I'm right, I'm just saying that things are changing rapidly, people are investing in that change, and that is a recipe for surprising results.