Sport vs. Non-Sport the same motor?

[TEG]

Would think "hand wound" could be duplicated with the proper machine and machine vision.

Yeah, it is impressive that human hands can outdo the machine on something like this.
I bet it requires some skill to do it right. Probably not everyone is qualified / capable of winding one to Tesla's specs.

I bet a machine could do a decent, but not quite as good job in a small fraction of the time. It probably only makes sense to hand wind motors on a low volume, high value vehicle.
(Particularly using SF Bay Area labor, not some sweat shop in a far away place.)

 

[TEG]

...why is its HP rating exactly the same as the hand wound Sport model's motor?...

The HP quotes are sometimes baffling too. I think sometimes they are mis-prints / mistaken publications. It can be hard to know what to trust as "authoritative". (Well, except maybe if you put a car on your own dyno.)

 

[Doug_G]

Would think "hand wound" could be duplicated with the proper machine and machine vision.

Perhaps. In my experience these sorts of "intelligent systems" are often a bit hard to design, because the "experts" who do it by hand literally don't really know how they do it. They just do it "by feel". That makes it very hard to program. The human brain is an amazing thing.

 

[smoothoperator]

Yeah, it is impressive that human hands can outdo the machine on something like this.
I bet it requires some skill to do it right. Probably not everyone is qualified / capable of winding one to Tesla's specs.

I bet a machine could do a decent, but not quite as good job in a small fraction of the time. It probably only makes sense to hand wind motors on a low volume, high value vehicle.
(Particularly using SF Bay Area labor, not some sweat shop in a far away place.)

Are the electric motors actually manufactured in the bay area? I thought I read somewhere that they were manufactured to Tesla's specs by a supplier in China/Taiwan....

 

[richkae]

Tesla published documents describing how the maximum power output of the Sport PEM is higher than the standard PEM - perhaps the only difference is the PEM.
Its easier for the marketing materials to reference a better motor because people understand motors and not PEMs.

 

[tdevince]

PEMs are interchange. My non-sport is currently running with a Sport PEM. Hardware is identical. Programming is model specific

 

[SByer]

Would think "hand wound" could be duplicated with the proper machine and machine vision.

+1 - I can't believe that a winding machine designed for maximum windings 'faster and somewhat cheaper than a human' couldn't do better, faster, and more consistent than human. 'Failures' I've seen (what was that 6-wheeled thing?) have always failed to try and slow down the rate at which the winding machine was actually winding.

 

[smorgasbord]

+1 - I can't believe that a winding machine designed for maximum windings 'faster and somewhat cheaper than a human' couldn't do better, faster, and more consistent than human.

That's probably true if you're willing to build a single purpose winding machine to wind just these motors. But the winding machines I've seen on TV/YouTube are generic. There was a show on the Eliica electric car which has an electric motor in each of its 8 wheels. Bad on the unsprung weight, but still a fast car in a straight line. Anyway, there was a motor winding segment, which involved some trial and error (mostly broken wires) to get to motor windings that the designer was happy with.

There are still manufacturing examples in this day and age where people do better jobs than machines. My hand lasted Lucchese boots look better and are more comfortable than machine lasted boots. I have some hand woven rugs, which have a tighter weave density than machine made rugs. That's not to say that one couldn't build a machine to do these things better, but no-one seems to have done it yet. Maybe motor winding machines are the same?

 

[doug]

Would think "hand wound" could be duplicated with the proper machine and machine vision.

Maybe it's wound by this hand:

http://www.youtube.com/watch?v=-KxjVlaLBmk

 

[stopcrazypp]

Perhaps. In my experience these sorts of "intelligent systems" are often a bit hard to design, because the "experts" who do it by hand literally don't really know how they do it. They just do it "by feel". That makes it very hard to program. The human brain is an amazing thing.

This reminds me of a story I read in a UI class. It's about the Matsushita bread making machine. Back in 1985, no one was able to figure out how to make a bread making machine that can simulate the dough-kneading process that took years of apprenticeship for a baker to learn. It was only after someone from the company's software development team took an actual apprenticeship with a head baker that they were able to make such a machine.

This wiki page has a short section about it. http://en.wikipedia.org/wiki/Tacit_knowledge#Examples

I suspect the story is probably similar for motor winding machines.

 

[TEG]

Are the electric motors actually manufactured in the bay area? I thought I read somewhere that they were manufactured to Tesla's specs by a supplier in China/Taiwan....

I think they used to be made in Taiwan, but they moved the manufacturing "in house" to Palo Alto. Possibly when switching from 1.5 (2008s) to 2.0 (2010s).

TESLA MOTORS INC - FORM 10-K - March 3, 2011

Powertrain Component Manufacturing
In addition to developing our planned Model S and future vehicle manufacturing facility in Fremont, California, we are currently designing and manufacturing lithium-ion battery packs, electric motors, gearboxes and components both for our vehicles and for our original equipment manufacturer customers in our electric powertrain manufacturing facility in Palo Alto, California. Specifically, at the Palo Alto facility:
...

Motor. We manufacture our induction motors. We have operated our own manufacturing facility in part to protect the proprietary technology we developed for our motor.
...
​

​

 

[TEG]

http://www.apec-conf.org/2010/images/PDF/2010/Plenary/plenary-presentation_jb_straubel.pdf

...Tesla Roadster Sport
Inverter phase current increased to 900A rms maximum...

 

[richkae]

Thanks TEG, thats the document I was referring to. I thought that meant that the PEM had been changed to produce more current.
It could also mean that the PEM could always handle that much current, but that the sport motor could handle more current, so they just change the programming in the PEM to deliver more.

 

[vfx]

Maybe it's wound by this hand:...

Great video! Wonder where it's weight limit is...

 

[TEG]

That Robot hand is cool, but I wonder how many of the clips were "cherry picked" successes.
Do they have a bunch of outtakes where the hand drops the cellphone or doesn't bounce the ball very many times?

They did pick a nice assortment of activities to put it through. I bet each one required a subtantial amount of programming.

 

[TEG]

Something I did for another thread, but very relevant here:
----
Here is a mock-up of what 2.0 Sport vs non-sport might look like...

I think some of the confusion in this area is because of the old 1.0 & 1.5 power/torque charts which were published a while back.
The 2010 & 2011 models with 2.0 powertrains have some different characteristics compared to the 2008s.

(Getting historical here: Some of the very first Roadsters has 1.0 powertrains with much less low end torque. Those later got upgraded to 1.5 with a significantly improved PEM to make up for the loss of a lower gear. )

 

[Norbert]

Maybe it's wound by this hand:

Video gone.

Is it still somewhere else?

 

[doug]

Video gone.

Is it still somewhere else?

Updated with a working link.
http://www.youtube.com/watch?v=-KxjVlaLBmk

 

[TEG]

Here is a mock-up of what 2.0 Sport vs non-sport might look like...

By the way, when you talk about sustained acceleration - like 0-60, not just instantaneous acceleration ("kick in the pants") what you care about is the area under the HP graph for the rev range in question. For for instance, you could compare two power sources, both with the same peak HP, but find that one develops more HP earlier in the rev range before tapering off to the same maximum.

In the above chart, the higher initial torque causes the HP to rise more quickly, producing better acceleration even though it stops at the same max HP.

Another thing to notice is that when you push the flat torque peak up higher, it moves the HP graph to the left. That triangle of area between the green and blue lines is where the Sport model shows its' benefit.
So, again, HP rises more quickly at first.
If someone says that a base and sport both have 288hp max, that doesn't tell the whole story. Another question would be "how much horsepower do they have at 3000 RPM?". In that case, the base might be something like 100hp, where the sport is more like 125hp...