# Help with motor decision (Kostov vs NetGain)



## SCEV (Apr 10, 2012)

I'm just starting my conversion (86 Porsche 944 Turbo) and trying to figure out my parts list/budget. I'm having trouble deciding between the NetGain motors and Kostov motors. I'm planning to have around a 240V nominal pack (could change one way or the other depending on motor), and hoping for better than stock performance.

Attached is a spreadsheet I started putting together (you'll see lots more than the motor options, ignore the rest it's all just notional). Can someone verify the stats in the motor section? I can't figure out how to compare apples to apples with these, since the NetGain specs give torque and such at one voltage/amp and the Kostov at another.

Any other big pros/cons for the two brands (or specific models) anyone can share??


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## somanywelps (Jan 25, 2012)

You want the voltage above 300V to compensate for sag under acceleration. Especially with smaller kwh packs.


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## SCEV (Apr 10, 2012)

somanywelps said:


> You want the voltage above 300V to compensate for sag under acceleration. Especially with smaller kwh packs.


Only if I get a motor rated for 250ishV right? A NetGain motor rated for 170V should be fine with a pack voltage at nominal 240V...


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## ruckus (Apr 15, 2009)

Regardless of which one you choose, I would upgrade the brushes to Helwig from the beginning (Netgain is already doing this). This will improve you temp, power, and longevity according to recent tests at EVTV.

Cheers


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## Yabert (Feb 7, 2010)

SCEV said:


> A NetGain motor rated for 170V should be fine with a pack voltage at nominal 240V...


Yes, but if you expect high performance you will need more than 170v (exept if you think about two motor).
From your first question, I was thinking that you only want to choose between Warp 11 HV and a Kostov Alpha.

Both motor will be impressive with proper battery pack.

Personnaly, I'm impress by the high efficiency of the Alpha (even at 500A). It's probably a good sign of what it can do at 1000A (or more).

But, the Warp 11HV have proof few time that it's a beast (Crodriver BMW, Valerun BMW)


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## Tesseract (Sep 27, 2008)

ruckus said:


> Why do your only options contain problematic and failure-prone brushes? Regardless of which one you choose. This will be the issue.
> 
> I would look at BLDC such as this before deciding.
> http://www.greenstage.co.nz/PDFs/Scott_Drive_100.pdf
> ...


Uh-huh... Surely a Chinese motor controller will be the very paragon of reliability and performance in comparison...

Maybe this "Scott Drive" will be the exception that proves the rule, but as I pointed out in the thread about it, it's the same type of motor/controller as used in small computer fans - an application where low starting torque and high amplitude torque ripple (+/-15%) isn't an issue. In a traction drive, both of those downsides are objectionable, if not crippling.

I'd hold off on recommending this system until someone unbiased has actually tried it. On paper it doesn't look particularly impressive to me. $5500 for 80kW peak isn't any more powerful than the Curtis 1238 + AC-50, and it's actually more expensive than the latter system when purchased from a known good vendor like frodus here.


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## ruckus (Apr 15, 2009)

Tesseract said:


> Uh-huh... Surely a Chinese motor controller will be the very paragon of reliability and performance in comparison...


I would actually recommend one of the MADE-IN-USA water-cooled brushless motors... Except, there are none for sale. 

If you want air-cooled BLDC you can call Powertec. With typical american service they won't bother to call you back or even send you a price sheet with big numbers on it. 



Tesseract said:


> Maybe this "Scott Drive" will be the exception that proves the rule, but as I pointed out, it's the same type of motor/controller as used in small computer fans - an application where low starting torque and high amplitude torque ripple (+/-15%) isn't an issue. In a traction drive, both of those downsides are objectionable, if not crippling.


Really? Then why has heavy industry shifted from brushed motors to BLDC? Again, Powertec and other BLDC documentation show very impressive starting torques so this argument seems a bit of a red herring. 

Most electric motors don't have a torque problem, they have a hp problem. Especially inefficient air-cooled Brushed DC motors. Look at the specs, this motor weighs 54lbs LESS than the 11" yet is rated at 45+ hp continuous. Brushed motors just can't compete for long high-speed driving. How many OEMs use brushed motors? None. Hmmmm, wonder why? 



Tesseract said:


> I'd hold off on recommending this system until someone unbiased has actually tried it. On paper it doesn't look particularly impressive to me. $5500 for 80kW peak isn't any more powerful than the Curtis 1238 + AC-50, and it's actually more expensive than the latter system when purchased from a known good vendor like frodus here.


It is called the Scott Drive 100 because the motor is rated at 100kw peak, not 80. They don't list a max wattage for the controller but it calculates to 200kva. According to the listed torque figures, the AC-50/Curtis is not in the same league. The "100" is the "derated" model. More power and voltage should be coming soon.

The Scott Drive system is currently installed and being used in several cars in NZ. Several thousand km and no problems reported. The controller is not Chinese, but made with quality in New Zealand. 

I look forward to meeting you (I think your controllers are brilliant) at EVCCON where I will likely have a Scott Drive for display along with the "brushed" '37 Jaguar.

Cheers


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## DavidDymaxion (Dec 1, 2008)

Racers seem to prefer the Netgain motors. Kostovs are a bit cheaper. I think interpoles are a plus, all the Kostovs have interpoles but just one of the netgain motors do. I have a Kostov 11 alpha, sepex wound on order.


SCEV said:


> I'm just starting my conversion (86 Porsche 944 Turbo) and trying to figure out my parts list/budget. I'm having trouble deciding between the NetGain motors and Kostov motors. I'm planning to have around a 240V nominal pack (could change one way or the other depending on motor), and hoping for better than stock performance.
> 
> Attached is a spreadsheet I started putting together (you'll see lots more than the motor options, ignore the rest it's all just notional). Can someone verify the stats in the motor section? I can't figure out how to compare apples to apples with these, since the NetGain specs give torque and such at one voltage/amp and the Kostov at another.
> 
> Any other big pros/cons for the two brands (or specific models) anyone can share??


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## Tesseract (Sep 27, 2008)

SCEV said:


> Only if I get a motor rated for 250ishV right? A NetGain motor rated for 170V should be fine with a pack voltage at nominal 240V...


Yep - 240V is plenty of voltage to maintain a nice, flat power band with a NetGain advanced timing motor. You might want to run 300V+ if you choose one of the highest voltage Kostov motors, or the interpoled WarP-11HV, but then you won't want to push as much peak current through them (no free lunch - higher voltage tolerance generally means lower current tolerance).




ruckus said:


> I would actually recommend one of the MADE-IN-USA water-cooled brushless motors... Except, there are none for sale.  ...


Au contraire... the Remy HVH250 is made in the USA, is liquid cooled and can be purchased retail from: http://vaxosystems.com/store/category/53-motors.aspx



ruckus said:


> It is called the Scott Drive 100 because the motor is rated at 100kw peak, not 80.


You might want to take a closer look at the PDF you linked to above. If you multiply the peak voltage and phase current ratings for the motor - even assuming that both are RMS (DC equivalent) values - that's still only 67kW of peak power (320V * 121A * 1.73). 

NB - I didn't respond to the rest of your post because it was mostly you trying to prove AC is better and who am I to argue otherwise?


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## somanywelps (Jan 25, 2012)

DavidDymaxion said:


> I have a Kostov 11 alpha, sepex wound on order.


I was wondering about this. Who did you order it from?

(Also what controller are you planning (I'm waiting for one that's not out yet))


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## SCEV (Apr 10, 2012)

Tesseract said:


> Yep - 240V is plenty of voltage to maintain a nice, flat power band with a NetGain advanced timing motor. You might want to run 300V+ if you choose one of the highest voltage Kostov motors, or the interpoled WarP-11HV, but then you won't want to push as much peak current through them (no free lunch - higher voltage tolerance generally means lower current tolerance).


So then what is the advantage of the WarP 11HV over the WarP 11? The regular 11 is $600 cheaper, can take more amps, and requires lower pack voltage (saving me more $).

I'm really down to WarP11, WarP11HV, K10 144V, K11 192V, K11 250V SFM and K11 250V PFM (WarP 11 and K11 192V are my top two ATM). Can anyone help spell out the differences in these, with specs if possible? Like I said in my first post I looked up the specs but don't understand how to compare apples to apples based on what I found.


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## somanywelps (Jan 25, 2012)

SCEV said:


> So then what is the advantage of the WarP 11HV over the WarP 11? The regular 11 is $600 cheaper, can take more amps, and requires lower pack voltage (saving me more $).
> 
> I'm really down to WarP11, WarP11HV, K10 144V, K11 192V, K11 250V SFM and K11 250V PFM (WarP 11 and K11 192V are my top two ATM). Can anyone help spell out the differences in these, with specs if possible? Like I said in my first post I looked up the specs but don't understand how to compare apples to apples based on what I found.


The higher the voltage, the less battery amps you need to draw for the same kw (HP). (Read as: less amps for a given RPM.)

This requires a high pack voltage, but is easier on the batteries, and more efficient.

You also tend to get higher torque numbers, but the Warp 11 is a non-interpole advanced timing motor and the Warp 11 HV is a Warp 9 armature with interpoles and neutral timing.

Edit: look at the 192V K11 and the 250V K11 (both in series mode). Now look at the bottom at the torque. Notice anything?


Edit2: Multiply Voltage*Amps to get your kw. Then multiply by efficiency to get your power at the shaft (you can convert it to HP if you want).

K11A 250V:
0.4585365853658537x + -35.26829268292684

312ft*lb per 1 @1000A
624ft*lb per 2 @1000A
177ft*lb per 1 @600A
354ft*lb per 2 @600A
143ft*lb per 1 @500A
286ft*lb per 2 @500A

K11 250V:
0.47586206896551725x + -22.93103448275862

334ft*lb per 1 @1000A
668ft*lb per 2 @1000A
193.67ft*lb per 1 @600A
387ft*lb per 2 @600A
158.57ft*lb per 1 @500A
317.14ft*lb per 2 @500A

K9 220V:
Torque=0.4074074074074074*Amps + -27.703703703703695

300ft*lb per 1 @1000A
600ft*lb per 2 @1000A
159ft*lb per 1 @600A
308ft*lb per 2 @600A
130ft*lb per 1 @500A
260ft*lb per 2 @500A


Warp11HV:
0.45918367346938777x + -102.51020408163265

1000A 357ft*lb


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## Tesseract (Sep 27, 2008)

SCEV said:


> So then what is the advantage of the WarP 11HV over the WarP 11? The regular 11 is $600 cheaper, can take more amps, and requires lower pack voltage (saving me more $).


The -11HV is supposed to have more commutator segments (though I don't know this for sure!) and along with the interpoles allows it to produce more torque per amp and handle a much higher voltage (288 vs. 170) than the stock WarP-11. It can't take as much current for as long as the -11, but it still puts out a higher peak power (at least one documented excursion to 500hp on a chassis dyno).



SCEV said:


> I'm really down to WarP11, WarP11HV, K10 144V, K11 192V, K11 250V SFM and K11 250V PFM (WarP 11 and K11 192V are my top two ATM). Can anyone help spell out the differences in these, with specs if possible? Like I said in my first post I looked up the specs but don't understand how to compare apples to apples based on what I found.


Can't help you there. I don't think anybody has true comparative data for all these different motors, or even more than two of them.


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## ruckus (Apr 15, 2009)

Tesseract said:


> Au contraire... the Remy HVH250 is made in the USA, is liquid cooled and can be purchased retail from: http://vaxosystems.com/store/category/53-motors.aspx


Thanks for the link. Always happy to learn about something new.  
...and only 3x the price for the same 100kw. 



Tesseract said:


> You might want to take a closer look at the PDF you linked to above. If you multiply the peak voltage and phase current ratings for the motor - even assuming that both are RMS (DC equivalent) values - that's still only 67kW of peak power (320V * 121A * 1.73).


The ac-50 is 50hp and 110ftlbs Peak.
The Scott Drive is 100hp and 200ftlbs Peak. 2X the power seems pretty significant for that extra $900.

There is a big difference between "peak" and "rated". You are using the rated voltage and the rated amps and calling them peak. The Scott Drive motor can supposedly handle 540vdc (nominal) - I will be testing at even higher voltages with a "custom" Scott Drive controller. 



Tesseract said:


> NB - I didn't respond to the rest of your post because it was mostly you trying to prove AC is better and who am I to argue otherwise?


Really? I didn't see that in my post. I am not a big fan of AC. It is more accurate to say that I am not blindly loyal to products that have a very high failure rate. Tim Cattellier is on his 3rd motor. Rickard lost 1 out of 3 so far. I am not getting even close to the rated hp. The stories of failure are growing daily. If controllers were blowing at this rate folks would quickly label them "worthless". 

Nothing could be worse for the EV movement in the long run. Just as it is building steam with awesome batteries and controllers, the motors have become the new weak link. Perhaps with some tweaking (like Helwig brushes and high-power blowers) the brushed motors can stay on as an option. But to have SO many people pouring their savings and time into their project only to end up with an expensive fireworks display is unworkable.

I only seek a reliable and affordable drive system. Power and price is nice, but reliability is a MUST. I cannot at this time recommend a brushed motor to a person doing a conversion until these issues are resolved. I am sorry to bring such a dark cloud of reality into the open. But I believe it is better to deal with it now than to sweep it under the rug and have everybody hating EV's in 3 years.


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## Batterypoweredtoad (Feb 5, 2008)

Rukus-you are on a strong apples to oranges streak. You keep saying the high failure rate of DC but what you are really seeing is the sudden emergence of cheap high power DC controllers. Of course the AC systems are not blowing up motors because all the controllers can manage is the motors rated continuous KW and maybe 2x that peak. A Soliton JR is rated to continuously push 4x the continuous capability of a K11 Alpha and that is Evnetics entry level controller. You put up baby AC systems and say they are more reliable than DC because people who abused their DC motors at 4x the power capability of your AC system blew the motor up.


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## ruckus (Apr 15, 2009)

Batterypoweredtoad said:


> what you are really seeing is the sudden emergence of cheap high power DC controllers. A Soliton JR is rated to continuously push 4x the continuous capability of a K11 Alpha and that is Evnetics entry level controller.


That is my point exactly. First it was the weak lead batts, then the wimpy controllers, now that both of these have become ferocious it is the brushed motors that are suffering high failure rates. Perhaps brush improvements will solve the problem, perhaps not. At least you are one of the few who admits there is a problem.



Batterypoweredtoad said:


> You put up baby AC systems and say they are more reliable than DC because people who abused their DC motors at 4x the power capability of your AC system blew the motor up.


Not sure I can agree that these are "baby" systems. Powertec E215 is only 211 lbs and is rated at 86hp CONTINUOUS and 500 ftlbs of torque. That will blast and keep blasting the doors off any brushed dc motor used in EV's.

Please post Brushed dc specs that are 4x that as you claim. 

The people suffering failures are not abusing their motors. They are failing right out of the box or after just a few hundred miles. Of course, if you bother to contact people on evalbum with high ev miles you will get to hear the same story over and over that goes, "everything was great until one day.. "Poof"... the brushes dissolved into nothing. " 

Why are you pretending this is some type of rare event caused by abuse?


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## somanywelps (Jan 25, 2012)

ruckus said:


> Not sure I can agree that these are "baby" systems. Powertec E215 is only 211 lbs and is rated at 86hp CONTINUOUS and 500 ftlbs of torque. That will blast and keep blasting the doors off any brushed dc motor used in EV's.
> 
> Please post Brushed dc specs that are 4x that as you claim.


And the motor alone costs *OVER $10,000*. What controller were you planning on using with it again? 

Edit: it's also got a maximum RPM of 3600 which is completely useless. 

Too much torque to use with a stock transmission, and too little RPM to use without one.


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## Batterypoweredtoad (Feb 5, 2008)

I will gladly admit that we are getting to nearly enough power.  

Please spec me a system that has the same continuous rating and peak rating as a K11 alpha and soliton Jr at the same price. Heck, please spec me an equivalent AC system at twice the price. If that doesn't work maybe go 4x the price?


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## ruckus (Apr 15, 2009)

somanywelps said:


> Edit: it's also got a maximum RPM of 3600 which is completely useless.


No no, that's the RATED rpm (the rpm at which that hp and torque are guaranteed) The peak hp is actually over 5000 rpm and the motors go to 8000+. 3600rpm is a standard speed for rating industrial motors.

Please don't confuse the 2 separate arguments here.

1. many are claiming bldc are weak with lousy torque. The Powertec stats easily refute this silly argument since they are much more powerful per pound than brushed dc.

2. Many are claiming BLDC are crazy expensive. I have found that not to be true either. There are new offerings on the market that are VERY comparable to the current crop of Brushed DC.

Not sure of Kostov prices, but Netgain 11" are $3000. A decent controller is $2000-3000. Depending on controller you may have to purchase, add and house a contactor, 12v circuits, etc.

So you are talking $5000-6000 for the current brushed setup that is rated at 35hp continuous.

This BLDC system is $5495. 
http://shop.greenstage.co.nz/product/100kw-scott-drive-ac-inverter-and-motor-package
It comes with contactors and 4 10amp 12v circuits. The controller is rated at 180kw and the motor at 100kw peak, 35kw continuous. That is 47hp continuous from a motor that is little more than half the weight of the Warp 11. 

I have done a little digging into this motor and it has potential to handle 540+vdc. That will raise the peak hp and torque values quite a bit (continuous rating will be fairly similar since that is based on cooling rate).

This combo is reportedly working great for several conversions in NZ with several thousand km and counting. I am thinking to import and test one since the main argument against it is that everybody doesn't already use it.

Cheers


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## somanywelps (Jan 25, 2012)

ruckus said:


> No no, that's the RATED rpm (the rpm at which that hp and torque are guaranteed) The peak hp is actually over 5000 rpm and the motors go to 8000+. 3600rpm is a standard speed for rating industrial motors.


 I don't see that, but regardless, it's 10 grand so it's useless.


ruckus said:


> Please don't confuse the 2 separate arguments here.
> 
> 1. many are claiming bldc are weak with lousy torque. The Powertec stats easily refute this silly argument since they are much more powerful per pound than brushed dc.


 NOT AT THE SAME COST LEVEL. AND THE TORQUE IS HIGH, BUT THE KW rating is shit.[/Quote]


ruckus said:


> 2. Many are claiming BLDC are crazy expensive. I have found that not to be true either. There are new offerings on the market that are VERY comparable to the current crop of Brushed DC.
> 
> Not sure of Kostov prices, but Netgain 11" are $3000. A decent controller is $2000-3000. Depending on controller you may have to purchase, add and house a contactor, 12v circuits, etc.
> 
> ...


1) Cost 

2) You keep ignoring that a K11+Soliton 1 will eat the Scott thing alive, EVEN IF IT WORKS AS ADVERTISED. 

The K11 is 50kw continuous. 

A more appropriate 135kw peak Brushed DC system(K9 220V+soliton Jr.) would be $3700. 

If you wanted to go old school you could go with a Zilla 1k-HV.


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## ruckus (Apr 15, 2009)

somanywelps said:


> THE TORQUE IS HIGH, BUT THE KW rating is shit.


 

Dude! You are looking at the wrong chart which is configured to 1800rpm, not the pdf? Industrial motors are officially rated at 1800 and 3600rpms and they use different wire connections for the different rpm ranges. Look at the pdf. (or don't) The rating is 500ft lbs and 86 hp at 3600rpm. 95 hp max. That will eat your Kostov-soliton thingy in a highway race.

Yes, it is expensive but it shows the power potential (and it's not even water cooled!). The Chinese could make an exact copy for less than half the dough. It just hasn't been done yet. (or maybe it has and is lurking out there..)



somanywelps said:


> 2) You keep ignoring that a K11+Soliton 1 will eat the Scott thing alive, EVEN IF IT WORKS AS ADVERTISED.


Actually, I have spec sheets showing the motor pumped up to 85kg and 540v, 160hp peak, 80hp continuous, and a decent 500nm torque. If I can get my hands on one with a "custom" controller I will attempt to push the voltage/torque limit even further.

I look forward to the race with your Kostov.


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## Batterypoweredtoad (Feb 5, 2008)

Lol-Oh yeah? Well my imaginary system can beat up your imaginary system.


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## somanywelps (Jan 25, 2012)

ruckus said:


> Dude! You are looking at the wrong chart which is configured to 1800rpm, not the pdf? Industrial motors are officially rated at 1800 and 3600rpms and they use different wire connections for the different rpm ranges. Look at the pdf. (or don't) The rating is 500ft lbs and 86 hp at 3600rpm. 95 hp max. That will eat your Kostov-soliton thingy in a highway race.
> 
> Yes, it is expensive but it shows the power potential (and it's not even water cooled!). The Chinese could make an exact copy for less than half the dough. It just hasn't been done yet. (or maybe it has and is lurking out there..)
> 
> ...


The kostov+ soliton 1 spits out ~360 HP at the shaft (~420hp prior to efficiency losses) with a soliton 1 at max. (versus your 95hp max)

You still haven't answered what controller you're going to use.

Also, lol $10,000 for your motor.


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## ruckus (Apr 15, 2009)

somanywelps said:


> The kostov+ soliton 1 spits out ~360 HP at the shaft


For how many seconds before destruction? Dyno data?

I think you misunderstand the difference between industrial ratings and civillian product ratings. The industrial ratings are extremely conservative because they run machines that keep people alive like mining air pumps. If you push your motor to 4x the rating and blow it, big deal. If a Powertec motor fails, PEOPLE DIE. There is a magnitude of difference.

I am sure the Kostov+soliton is very fast. Like I said, I look forward to the race whether I win or not I will still be grinning. How about next year at EVCCON? See you there?

p.s. It is not "my" motor, only a working example for those who claim BLDC suck.


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## dladd (Jun 1, 2011)

ruckus said:


> p.s. It is not "my" motor, only a working example for those who claim BLDC suck.


I think you are creating this drama in your own mind. Generally speaking, people have not been claiming that BLDC suck, in fact quite the opposite. Most are very interested in it, and see the potential. The claims I've seen are simply that user available BLDC is not there yet. Brushed DC is.

I have a DC motor. It was a proven entity that I knew would offer the performance I wanted. I have no allegiance to DC, I just wanted what would work at a good pricepoint. I am thinking of trying some of these new Helwig brushes to see what the fuss is about. I don't have any overheating issues, but if they really improve efficiency that would be worth a few hundred bucks to try out.

I'm sorry you had a bad experience with Netgain, but it you seem to be taking the anger thing a bit too far.


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## somanywelps (Jan 25, 2012)

ruckus said:


> For how many seconds before destruction? Dyno data?


It's rated for 10 seconds at that power, so if you keep it under that it should be fine.

At that power level you're already far over 100mph.



ruckus said:


> I think you misunderstand the difference between industrial ratings and civillian product ratings. The industrial ratings are extremely conservative because they run machines that keep people alive like mining air pumps. If you push your motor to 4x the rating and blow it, big deal. If a Powertec motor fails, PEOPLE DIE. There is a magnitude of difference.


 Sorry, I don't believe this bit. You'll need real sources.

Also pretty sure netgain/warfield and kostov motors are industrially rated if you look at some of their other motors.

You still haven't given a viable controller.


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## ruckus (Apr 15, 2009)

No anger, no drama.

I have replied with facts and examples. I even make positive suggestions that might help solve the problems. 

It would be a lot easier for me if Brushed motors were as awesome as they pretend. I wouldn't have to search the world over for a reliable solution. I certainly wouldn't have to deal with the constant arguments of those in denial.

This issue is more about human psychology than a specific technology. Most people become fans of what they have. They just can't help it. It is human nature. Since most people on the forum have Series DC, it has become a fan-club for those motors. Anyone who brings up issues, failures, or alternatives gets shouted down or driven away to another forum.

I have nothing to gain from bringing up these issues except that perhaps the motor companies will make design alterations that solve them. Would that not be better for everybody? All folks have to do is acknowledge there is a problem and work together to solve it. Instead it is just a constant stream of denial and misinformation.


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## Batterypoweredtoad (Feb 5, 2008)

Where is anyone saying brushed motors are the best motors? They are the available motors within a diy-er's budget. The diy ev world is in a shift right now where people are having to switch to a more power tolerant brushed motor because the controllers have gotten better. If you were happy with a old school 144 volt 500 amp curtis controller you could keep a 7" or 9" brushed motor alive for as long as you wanted. If you want a Soliton 1 you had better step up to a bigger motor. If you want a combo that you cannot kill you should probably use a hefty 11" behind a Jr or turn down the settings on your Soliton 1. 

All the available brushless systems sell a matched motor and controller pair that doesn't push the motor much more than its continuous rating. Sure your motor will survive forever, but if you can afford it, it will be a slow setup. That slow setup will be easily matched by a brushed setup that is equally as indestructible and cheaper. A K11 Alpha or Warp 11HV with a junior will be equally as reliable and outrun a Curtis HPEV system for less money. 

Just a FYI: Tessarect was one of the first to point out that the commonly used 9" brushed motors live a very very short life at 1000Amps. He even provided a few videos of said destruction.

Right now you are claiming the superiority of a motor that isn't available at even remotely reasonable prices and using a custom controller that doesn't exist yet to show what the motor can do.


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## ruckus (Apr 15, 2009)

Batterypoweredtoad said:


> Where is anyone saying brushed motors are the best motors? They are the available motors within a diy-er's budget


I agree with you on most of what you say. I think the issue is nobody wants to admit there is a rash of failures happening right now. Everyone is pretending the EV solution is easier than ever. 11" motor and Soliton and you are set. End of discussion. The problem with that pat answer is two-fold:
1) You are talking about a $6,000 setup which suddenly opens up the potential for other options.
2) That is a lot of money on a motor that is suffering a high rate of failures.

Nobody wants to discuss that Tim Catellier is on his 3rd motor within a short time. Sure they were replace under warranty. That is great. But they still FAILED leaving him stranded. Would you give your grandmother that drive system? I wouldn't. If folks would discuss the issues and propose solutions, that would be great. Instead they deny the existence of problems and attack any alternatives by misrepresenting their cost and power. I don't think that will help the EV movement in the long run.

Cheers


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## somanywelps (Jan 25, 2012)

ruckus said:


> I agree with you on most of what you say. I think the issue is nobody wants to admit there is a rash of failures happening right now. Everyone is pretending the EV solution is easier than ever. 11" motor and Soliton and you are set. End of discussion. The problem with that pat answer is two-fold:
> 1) You are talking about a $6,000 setup which suddenly opens up the potential for other options.


It's more like $5400 for a K11+S1, and that's for high performance sports cars.

When you go down to BLDC power with kelly's and LVs it's like $1500-2000




ruckus said:


> 2) That is a lot of money on a motor that is suffering a high rate of failures.


 Still not seeing the links from you for the kostovs or netgains. I would bet they were running them FAR over rating (including overload rating).



ruckus said:


> Nobody wants to discuss that Tim Catellier is on his 3rd motor within a short time. Sure they were replace under warranty.


 Source link?

Also hopefully what he was running it with/at.

Still not seeing the controller you were planning to use with your $10000 BL motor.


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## ruckus (Apr 15, 2009)

Did you see the links I posted above? 

Tim Catellier has a blog. 
Jack Rickard has a TV show. And a blog.
I gave you other links as well. 

Tim is on his 3rd motor (and counting..)
Jack is down 1 out of 3 (and counting...)

There are more brush failures of both ADC and Kostov, (which I already linked) but why don't you start with Tim and Jack?


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## SCEV (Apr 10, 2012)

Sooo...anyone have any more input on the original topic of this thread (NetGain vs Kostov)?


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## ruckus (Apr 15, 2009)

If Kostov 11" are truly $1700 as claimed and Netgain are $3000, and they use pretty much the same technology, that is a no-brainer.

Cheers and good luck with your decision.


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## SCEV (Apr 10, 2012)

ruckus said:


> If Kostov 11" are truly $1700 as claimed and Netgain are $3000, and they use pretty much the same technology, that is a no-brainer.


That's the same conclusion I came to...was hoping someone that has experience with both could explain if the higher cost is validated. Seems most people have NetGains from what I've seen, so there must be a reason.


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## somanywelps (Jan 25, 2012)

ruckus said:


> If Kostov 11" are truly $1700 as claimed and Netgain are $3000, and they use pretty much the same technology, that is a no-brainer.
> 
> Cheers and good luck with your decision.



Kostov HV 11"(250V) are $2500 ($2700 with forced air), netgain 11HV is $3500 

Kostov LV 11"(*192V*) are $2200, netgain LV(*72V*) 11 is $3000 

The $1300-$1700 are the Kostov 9"'s. 

Edit: 
Netgain pricing: http://www.go-ev.com/End_User_Pricing.html 

Kostov pricing: http://kostov-motors.com/tractionmotors/kostovevmotors(ac-dc)/seriesdcmotorsforelectricvehicles/


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## ruckus (Apr 15, 2009)

somanywelps said:


> Kostov HV 11"(250V) are $2500 ($2700 with forced air), netgain 11HV is $3500
> 
> Kostov LV 11"(*192V*) are $2200, netgain LV(*72V*) 11 is $3000
> [/url]


Thanks for the info. 

I personally don't see $800-1000 in improvements between the two.

Of course, the NEW Netgains have the Helwig brushes. THAT is a big difference. You would have to calculate that into the Kostov price since running forklift brushes in an EV is like Russian Roulette.

Whatever you choose, make sure you run the best (Helwig) brushes and break it in real good...


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## DavidDymaxion (Dec 1, 2008)

I have an older Kostov 11 incher, and a friend of my has a newer NetGain 11 incher. His had fewer comm bars, and bigger brushes and brush leads. This implies his is a higher current but lower voltage motor compared to the Kostov. His motor is also slightly larger diameter and significantly heavier. 

If you want to play in the sepex world (like I am), Kostov is the way to go. If you want interpoles, Kostov is the way to go (although NetGain has an interpoled 11 incher now). Interpoles are supposed to make the motor a bit more efficient and more voltage tolerant, but they also rob some space, so the motor doesn't make as much torque.

The NEDRA racers seem to like the NetGain products -- given the above factors I can see why. Having said that, the new Kostov K11 alpha looks like an intriguing motor... In the pics the commutator looks huge and the cooling looks good. Can't wait until mine shows up someday soon!


SCEV said:


> That's the same conclusion I came to...was hoping someone that has experience with both could explain if the higher cost is validated. Seems most people have NetGains from what I've seen, so there must be a reason.


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## somanywelps (Jan 25, 2012)

ruckus said:


> Of course, the NEW Netgains have the Helwig brushes. THAT is a big difference. You would have to calculate that into the Kostov price since running forklift brushes in an EV is like Russian Roulette.
> 
> Whatever you choose, make sure you run the best (Helwig) brushes and break it in real good...


Do we have any quantitative data?

Also wasn't there something about brush dust with the helwigs?


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## ruckus (Apr 15, 2009)

somanywelps said:


> Do we have any quantitative data?
> 
> Also wasn't there something about brush dust with the helwigs?


ALL brushes create brush dust as they wear and can cause a full motor short. 

The quantitative data is the two EVTV shows (the first show also contains the Helwig lab testing results) AND the fact that Netgain has switched to them. Their in-house testing has shown them to be superior and worth the extra cost. You could email them and see if they would share their actual data. You could also do your own testing and post the results.

I have measured motor temp (250F  ) on a specific drive using forklift brushes. When they are switched to the Helwigs I will do the exact same drive at the same speed and report the temperature change (if any). 

May 18: http://www.youtube.com/watch?v=PTPNag6O8vw&feature=relmfu
May 25: http://www.youtube.com/watch?v=2KgXzd1hXes&feature=relmfu

I also know the exact amperage (700+) where that certain "frying" sound starts to happen. I will test if the new brushes can handle increased amperage after break-in. I like my bacon to sizzle, not my brushes. There is absolutely no point in buying a 1200amp controller if the motor can only handle 700. 

It must be kept in mind that the "average" builder is now using components that were "race" level a few short years ago.


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## somanywelps (Jan 25, 2012)

ruckus said:


> ALL brushes create brush dust as they wear and can cause a full motor short.
> 
> The quantitative data is the two EVTV shows (the first show also contains the Helwig lab testing results) AND the fact that Netgain has switched to them. Their in-house testing has shown them to be superior and worth the extra cost. You could email them and see if they would share their actual data. You could also do your own testing and post the results.
> 
> ...


While true, there was a post a while ago were someone noticed a large amount of brush dust on their new netgain motor, and upon contacting netgain, was informed that they had accidentally put helwig race brushes on it, which handle the higher power better, but don't last as long.


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## ruckus (Apr 15, 2009)

somanywelps said:


> While true, there was a post a while ago were someone noticed a large amount of brush dust on their new netgain motor, and upon contacting netgain, was informed that they had accidentally put helwig race brushes on it, which handle the higher power better, but don't last as long.


Those were likely the H49 compound which is very soft.

EVTV and Netgain are testing/using the H60 which is much harder.

Any (brushed) motor that is run in at low rpm may have a build-up of brush dust that should be cleared before high amp/volt use.

Cheers


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## nucleus (May 18, 2012)

*500 hp 11hv*



Tesseract said:


> The -11HV is supposed to have more commutator segments (though I don't know this for sure!) and along with the interpoles allows it to produce more torque per amp and handle a much higher voltage (288 vs. 170) than the stock WarP-11. It can't take as much current for as long as the -11, but it still puts out a higher peak power (at least one documented excursion to 500hp on a chassis dyno).


Tesseract, could you please share the link/documentation for the 500 HP on the dyno for the 11HV?

Nucleus


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## Tesseract (Sep 27, 2008)

*Re: 500 hp 11hv*



nucleus said:


> Tesseract, could you please share the link/documentation for the 500 HP on the dyno for the 11HV?
> 
> Nucleus


Took me a while to find it as it was from a thread started by CroDriver on his BMW "Bi-Moto" project (which ended up being a uni-moto, but that's another sad story altogether):

http://www.diyelectriccar.com/forum...-moto-ev-project-28287p40.html?highlight=dyno

The graph of his dyno run (made by our programmer, Qer) is in post #394 and some relevant, some not so relevant, discussion continues on the next few pages.


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## ruckus (Apr 15, 2009)

That is some mighty impressive peak power! 

Greater than 100% efficiency though? Was that issue ever resolved?


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## nucleus (May 18, 2012)

*Re: 500 hp 11hv*



Tesseract said:


> Took me a while to find it as it was from a thread started by CroDriver on his BMW "Bi-Moto" project (which ended up being a uni-moto, but that's another sad story altogether):
> 
> http://www.diyelectriccar.com/forum...-moto-ev-project-28287p40.html?highlight=dyno
> 
> The graph of his dyno run (made by our programmer, Qer) is in post #394 and some relevant, some not so relevant, discussion continues on the next few pages.


Thank you for taking the time to look that up for me. Mucho appreciado!


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## Roderick (Dec 8, 2013)

I'm not sure if this count as part of Kostov vs NetGain but didnt want to create new post just for this question. 

So, What exactly is the maximum continuous amp of Kostov 11 and Netgain? (The chart doesnt exactly identify the max continuous A) 
ie, can they run 250V 600A for 1hr? 

thanks


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## onegreenev (May 18, 2012)

Netgain can handle higher continuous current than Kostov. Netgain commutator is much more durable than the Kostov com. But for street use it really makes no difference. Yes, I own a Kostov. An older one at that.


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## Roderick (Dec 8, 2013)

So to sum this all up, 

Kostov:
better for short race 
good for normal street use 
cheaper 

Netgain:
better for average use including high way 
better durability

is this correct?
if not Where does kostov come in handy when compared to netgain other then their price?

Almost forgot , I'm comparing K11 alpha and warp 11"


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## onegreenev (May 18, 2012)

Roderick said:


> So to sum this all up,
> 
> Kostov:
> better for short race
> ...


Well I have interpoles and great torque from a bit larger armature. I will be setting my voltage limits to 156 volts and 500 battery amps and 800 motor amps. Being that I have interpoles I run my motor in a neutral timed position and no advancement. I do have a bit of adjustment if needed. I retain the lower end power but loose a bit more in the upper end. But I am only running in the 4500 rpm and less range anyway. No need to have my motor advanced. Runs strong on low to medium voltages. I leverage the transmissions ability to get good hwy speeds. No problem on the freeway even at 96 volts. 

You planning on a race vehicle?


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## Roderick (Dec 8, 2013)

onegreenev said:


> You planning on a race vehicle?


not so much as to race but high performance since im vehicle is sports car which had v8 and weigh 3500lb (original) 

I am just not sure if I can get good acceleration(0-60mph in 6-8sec) and decent average highway speed(80-100mph) out of the kostov 11k alpha.


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## onegreenev (May 18, 2012)

Roderick said:


> not so much as to race but high performance since im vehicle is sports car which had v8 and weigh 3500lb (original)
> 
> I am just not sure if I can get good acceleration(0-60mph in 6-8sec) and decent average highway speed(80-100mph) out of the kostov 11k alpha.


Have you considered one of the AC Siemens motors and DMOC controllers that are now on killer sale for $3600? Couple that with a nice high voltage system and run the max amps and you can have an excellent ride. 

DC setups will still require cleaning the motor out of the dust and keeping an eye on the commutator and brushes to prevent problems. DC are great but AC is much cleaner and no parts to wear except the bearings. 

You should be able to get close to an 8 second 60mph. With AC.


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## Roderick (Dec 8, 2013)

onegreenev said:


> Have you considered one of the AC Siemens motors and DMOC controllers that are now on killer sale for $3600? Couple that with a nice high voltage system and run the max amps and you can have an excellent ride.
> 
> DC setups will still require cleaning the motor out of the dust and keeping an eye on the commutator and brushes to prevent problems. DC are great but AC is much cleaner and no parts to wear except the bearings.
> 
> You should be able to get close to an 8 second 60mph. With AC.


Thanks for the tip but I believe DC is still the good cheap solution for me as to AC. tho In future I may upgrade to AC system. 
Also, as far as I know, K11 alpha + soliton1 can get me 0-60 in less than 8sec (at least on paper)


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