14kw continuous 94% efficient motor.......

[katou]

I attempted to answer a question I saw. Since then, the thread has been hijacked into a discussion of how motors should be rated.

Matt started this thread to discuss:

"14kw continuous 94% efficient motor..."

Let's go back to this. If someone wants to start this as a new thread, I'll happily discuss this until the cows come home.

Otherwise, I ask everyone to refrain from continuing the hijack, as I will from now on.

Katou

 

[liveforphysics]

Katou- Oops! I mean REdiculus, not Katau, sorry Katau!

I do understand the point you're trying to make. And I agree.

For a performance EV application though, which is what the motor is designed for and where Matts experience comes from, the motor is able to continously handle everything a lightweight high performance EV capable of feeding 14kw is able to dish out.

Do I think it would burn up mounted to an 18hp pump load in an industrial application running 24-7. Yes. I'm guessing it would be a crispy critter in under 20-30minutes. I think Matt thinks that as well.

For an LEV application though, I do think with a low enough turn-wind to get the RPMs up to 20,000 or so, and geared correctly to operate in this RPM range, that you wouldn't be able to ever hurt the thing in a LEV dumping all the power and energy that current battery and controller tech can feed it.

 

[etard]

Wait, this motor is no longer available. We will have to wait two years so that Matt can bench test 10 units at 14KW for 2 years. We will call this new rating system the REdiculous test. So check back in 2 years. :wink:

I'm just kidding, if Matt says it will do it, I'm sure it will, or he will address the issue and fix it. Matt is the pinnacle of good business practices and he stands behind his work. You won't be able to find another businessman with more transperancy and support than him.

Matt,
What will you be installing this motor into?? Is there a Recumpence motorcycle in the works?

 

[katou]

LFP, I'm on the other side - I agree with YOU, and I have from the start. I was trying to answer REdiculous' question so that he understands what you and I (and Matt, and others) already know.

I especially liked how you explained that the duty cycle of the motor doesn't need to be 100%. This is a valid point that in my reading, I have not seen elsewhere.

As usual, I enjoy the rigour of your explanations. It reminds me of a physics teacher I had once had, with your attention to the fundamental math, which considering your username, I suppose makes sense.


Given the power of this motor, relative to the motors that Matt is currently running in the trike, I wonder what will be the next step in performance?

From my reading of your trike thread Matt, it seemed like the drive wheel was losing traction long before the motors hit the wall. Maybe the next step is better traction? Dual drive wheels? Dually drive?

Katou

 

[John in CR]

He needs simplification. Matt already knows the motor handles 14kw without issue. Since the motor is 94% efficient, which means over 90% efficient in a fairly wide range of typical operation, and the motor has more surface area than the ones he's worked with often, the motor will have no problem shedding the waste heat that is less the 1kw (6% loss at 14kw is only 840W). That tells me the stated 14kw continuous is quite reasonable.

Luke's valid point is that there's no way you can realistically run the motor at 14kw continuously anyway. eg If you can put out 14kw continuously for 3 seconds, that will accelerate 350lbs from 0 to 50mph in 3 seconds, so you better hang on tight.

 

[liveforphysics]

LFP, I'm on the other side - I agree with YOU, and I have from the start. I was trying to answer REdiculous' question so that he understands what you and I (and Matt, and others) already know.
Katou

Oops! I edited my response above, my apologies friend, typed your name by mistake instead of REdiculous.

 

[recumpence]

Wow, go away from a thread for a few hours and so much happens!

Part of the problem is (admittedly) my lack of knowledge of the deeper areas of motor physics and theory. I run purely on my previous experience and technical knowledge of others. Now, that being said, as I mentioned I have run the Astro motors VERY hard. Heck, one of my trikes was put on a dyno that uses a 900 pound roller and tested. We did not time it, but that darn thing ran full throttle for a number of minutes (4 minutes?) at full throttle while under load. I am not worried in the slightest that this motor will perform far beyond anyone's expectations for its size.

I plan on installing my first motor in the big yellow trike and I will push it HARD. I am ordering a huge 500 amp Kelly controller for testing.

Oh, yes, traction is an issue. But, merely gearing up will load the motor enough for testing. Of course, that may mean 80mph gearing.

We shall see.........

Matt

 

[REdiculous]

Part of the problem is (admittedly) my lack of knowledge of the deeper areas of motor physics and theory. I run purely on my previous experience and technical knowledge of others.

I think the problem I'm having is that it's nearly impossible to make a fair comparison so I got a little worked up over the "4x the weight" and the "continuous" rating issue...my bad..

I've got a little blower and comparing it to an RC motor is tough, even though both excel at moving air. Which motor gets the home court advantage, RC or blower?..

The blower will run at its continuous rating for several years (in a marine env.) because it was made to supply fresh air to a bomb shelter...premature failure could mean asphyxiation...

Is it fair to give the RC motor the rating-advantage in that case? Not in my opinion.

 

[spinningmagnets]

If someone was moving up from an E-bike to a light E-motorcycle, what would the motor choices be? (we aren't allowed to ride an E-bike on the freeways, no matter how powerful it is). Due to the price ranges, I see more actual builds using an Etek or an Agni. I am unfamiliar with the occasionally-used ADC's and I assume they are heavier and more expensive, probably spec'd for higher power builds on heavier motorcycles?

"If" we had to add active cooling to actually achieve 14kW continuous (and that may not even be neccesary), based on Matts record, he will have no problem selling a pile of these to people who will beat them to within an inch of their lives. I for one, am curious to find out the power level that can be applied continuously that brings the motor to a stable temp that is 80% of its failure temperature (with no added cooling).

Matt has consistently under-promised and over-delivered. He has had many customers, they are easy to find and ask, but their posts so far seem to indicate a 100% satisfaction level. He is not looking for investors to fund vaporware development he has sketched on a napkin, this motor is real. He used existing parts where possible to keep the price down (lams)...this motor is a wonderful option.

 

[AussieJester]

Matt has consistently under-promised and over-delivered. He has had many customers, they are easy to find and ask, but their posts so far seem to indicate a 100% satisfaction level.

Well said spinningmagnets...

I am yet to see someone that has complained about Matts products, they
pretty much speak for themselves with their quality and performance.

KiM

 

[REdiculous]

I for one, am curious to find out the power level that can be applied continuously that brings the motor to a stable temp that is 80% of its failure temperature (with no added cooling).

Me first..you're second. :lol:

I think 140° is considered the continuous temp for most motors but I could be wrong. I checked some enamel wire I had handy and it says 80° C max..the first hit on google was the same. If I'm not wrong, then 160° is normally considered the 20min peak.

Matt has consistently under-promised and over-delivered. He has had many customers, they are easy to find and ask, but their posts so far seem to indicate a 100% satisfaction level.

I agree...I've read the threads and seen the vids..

It's just the rating system I'm buggin' about. I think Matt should use "sane" ratings because his motor will still come out on top. When your motor is that badass you don't need to redefine continuous, imo.

 

[Miles]

I think 140° is considered the continuous temp for most motors but I could be wrong. I checked some enamel wire I had handy and it says 80° C max..the first hit on google was the same. If I'm not wrong, then 160° is normally considered the 20min peak.

There are different grades of insulation - some good to over 200 deg. C. The Astro motors use Samarium Cobalt magnets - so no problems with temperature, there... Most RC motors would die pretty quickly, if you ran them at 160 deg. C. but the Astros (incl. Matt's version) would probably be ok. Not that it's a sensible thing to do. I guess you meant 160 deg. F, though

 

[MitchJi]

Hi,

I think 140° is considered the continuous temp for most motors but I could be wrong. I checked some enamel wire I had handy and it says 80° C max..the first hit on google was the same. If I'm not wrong, then 160° is normally considered the 20min peak.

It's just the rating system I'm buggin' about. I think Matt should use "sane" ratings because his motor will still come out on top. When your motor is that badass you don't need to redefine continuous, imo.

There are different grades of insulation - some good to over 200 deg. C. The Astro motors use Samarium Cobalt magnets - so no problems with temperature, there... Most RC motors would die pretty quickly, if you ran them at 160 deg. C. but the Astros (incl. Matt's version) would probably be ok.

So based on a piece of wire you "had handy" and a google search you came up with an incorrect definition and then you start "buggin" Matt for not using your definition?

 

[REdiculous]

So based on a piece of wire you "had handy" and a google search you came up with an incorrect definition and then you start "buggin" Matt for not using your definition?

Are you kidding me?

I never claimed to know what wire Matt uses. If he's using better wire then good on him...good deal.

160°F is hot for a typical motor, imo. You're free to have your opinion, but I don't like getting burned and I don't like burning up expensive toys. 140° F sounds hot enough..but normal. I haven't had a chance to really push my motor yet so it's only been barely luke-warm...

The point of that "I think" and "I could be wrong" post was to point out that I think this motor is great, for one, and to give my opinion on what I think of when I hear "continuous" and "peak" wrt to the temp of common motors.

 

[Miles]

Let's use consistent units. Centigrade is best, as it's an international forum.
80 deg. C. is the operating limit for standard grade NdFeB magnets.

 

[REdiculous]

Let's use consistent units.

It sucks when someone makes it hard to make a direct comparison, huh? :lol:

But, yeah, I didn't realize there was 200° C wire...wow!

 

[Miles]

Samarium Cobalt magnets can be used up to 350 deg. C. ...............

 

[recumpence]

We have seen 260f on these Astro motors and they have survived. Bob told me 160f is a good baseline as far as a safe temperature. When se spoke about this on the phone, I told him I have one build that I have been seeing 160f and he said "That is not hot. No worries. Just try keeping it at 200f or under."

Matt

 

[drewjet]

I had one of my astros up to 215 F, no problems. but for me at 250 F = $ OUCH $

 

[liveforphysics]

There are magnet wires rated for 220C operation, and I know Bob uses nothing but the highest temp stuff available. The bearings are at 220F forever, the magnets don't start to get soft on holding a field toll 350C.


There is no reason the Astros can't run be run at 200C till the cows come home.

This reason, along with the 15-20k RPM potential is why I have no issues with Matt claiming 14KW. With the available RPM range, it becomes a question of, can the motor make 6-8ft-lbs continously inside a 200C thermal equilibrium temp. The answer is yes.

 

[liveforphysics]

Oops, make that 250C... the polyamide insulated insulation is rated for years at 250C, anf its what Bob (and other premium motor guys) are using.

The difference is, for other motors they use Nd magnets, which become the temperature weak link, where the astros magnets are not a temp concern at all.

 

[Ypedal]

Have not read this entire thread, but i can confirm my Astro 3210 regularly gets up to 190~200f and keeps on ticking...

I'm a bit worried about the heat transfered to the belt tho.... so far so good but the entire 2 stage motor mount acts like a big heat sink and gets as hot as the motor...

 

[katou]

LFP, would you be willing to lay out your math step-by-step in calculating power limits including efficiency and heat rejection?

I have seen some of your calculations before, but not the whole process. If you include and seat-of-the-pants correction factors from your experience, it would be great if you included these also. Your inclusion of heat and efficiency is something I've not seen elsewhere.

This motor might be a good example case.

It would take a few minutes for you to do, but I know that I personally, (as well as many others) would very much benefit.

Katou

 

[spinningmagnets]

Here's a blurb from the E-motorcycle section on a new E-moto:

http://endless-sphere.com/forums/viewtopic.php?f=10&t=19094

"...The DC internal permanent magnet motor, which Czysz calls “D1g1tal Dr1ve,” is small enough to hide within the swingarm beneath the rear shock. The oil-cooled motor makes more power and torque than all three air-cooled motors in last year’s E1pc combined, while being smaller than one of them individually.

And crucially, it develops its 100 HP and 250 Lb-Ft of torque continuously. Air-cooled electric motors, on the other hand, quote peak figures which they’re only able to reach for a very brief period of time due to the rapid buildup of immense heat. Sometimes, they can only reach peak power for a fraction of a second.

The MotoCzysz can always make that 100 HP--as long as the batteries hold out, that is. The oil-cooling is key here, allowing the motor to exponentially shrink in size and weight for its output level; air-cooled motors are huge, so their large metal components can soak up the heat..."

 

[Miles]

Air-cooled electric motors, on the other hand, quote peak figures which they’re only able to reach for a very brief period of time due to the rapid buildup of immense heat. Sometimes, they can only reach peak power for a fraction of a second.

Hmmmmm That's a bit disingenuous.......