# Generic Torque/RPM/HP Curves



## Sunking (Aug 10, 2009)

I am looking fo ra generic Power curve to link to like this one minus motor manufacture/model of the one below. Something a little more like a realistic curves of a series wound DC motor used in a EV I have searched but unable to locate one.

THX


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## TX_Dj (Jul 25, 2008)

Like this? http://www.diyelectriccar.com/forums/showthread.php/warp-11-hv-performance-graph-41328.html


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## Sunking (Aug 10, 2009)

No not exactly but thanks for trying.


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## TX_Dj (Jul 25, 2008)




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## Sunking (Aug 10, 2009)

TX_Dj said:


>


Thank you, just what I was looking for, but it destroys what I thought I knew about Series Wound DC motors.

Everything I have read and taught says maximum torque and current is at stall and low RPM's and decays as RPM goes up. This chart is exact opposite. Where did I go wrong? 

HELP


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## maxvtol (Nov 11, 2009)

You original thoughts are still right, the chart is sideways to your example chart in post 1. Keep in mind the chart is with the motor at 72 volts under varying loads. 

Read the thread in my signature, might help a little.


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## Sunking (Aug 10, 2009)

maxvtol said:


> You original thoughts are still right, the chart is sideways to your example chart in post 1.


I must be missing something because what I see is maximum torque and current is at red line RPM's which is exact opposite of what I expected. I will take a look at your link.

THX


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## maxvtol (Nov 11, 2009)

Sunking said:


> I must be missing something because what I see is maximum torque and current is at red line RPM's which is exact opposite of what I expected. I will take a look at your link.
> 
> THX


Major would dissagree but I think the Netgain chart is confusing. 

Look at AMP curve, 
AMPS 100, Torque 10 ft lbs
AMPS 450, Torque 140 ft lbs

Look at RPM curve
RPM 4000, Torque 10 ft lbs
RPM 140, Torque 140 ft lbs

The scales on the vertical are different for each curve, everything based on torque.


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## Sunking (Aug 10, 2009)

maxvtol said:


> Look at AMP curve,
> AMPS 100, Torque 10 ft lbs
> AMPS 450, Torque 140 ft lbs
> 
> ...


OK said the blind man, I see. Makes more since now. I hate that chart.  Mine made a lot more sense.


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## Sunking (Aug 10, 2009)

Had to rush off earlier and there is still one thing bugging me about the chart, the Mechanical HP line. I assume it is charted off RPM vs Torque? So I would expect to see a Bell curve with a peak at approximately 2500 RPM with 80 ft/lbs. Instead I se a pretty flat linear line that peaks at 1800 RPM @ 140 ft/lbs? Am I reading that right?

One more question is there a spreadsheet with th edata points I could use to make my own chart with Torque, RPM, and HPso it looks like th eone I used in the example?


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## corbin (Apr 6, 2010)

Yes, there is a spreadsheet. 

http://www.corbinstreehouse.com/misc

I copied the data from various places. The .numbers one is the best one, but you need a mac, and Numbers. The other is an export to excel; I don't know how well it will work.

See this post for more information:

http://www.corbinstreehouse.com/blog/2010/05/plug-bug-more-motor-comparisions/

...and take the numbers for what you will; I'm not an expert.

corbin

corbin


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## maxvtol (Nov 11, 2009)

Sunking said:


> I hate that chart.  Mine made a lot more sense.


I'm with you on that!



Sunking said:


> there is still one thing bugging me about the chart, the Mechanical HP line. I assume it is charted off RPM vs Torque? So I would expect to see a Bell curve with a peak at approximately 2500 RPM with 80 ft/lbs.


On the Netgain chart, looks like from the RPM curve vs. Torque. 

The flat part of the torque curve is not show on this chart as you would see in a DC motor with controller setup. It's strickly at 72 volts and given varying loads. In a "normal" chart based on RPM, the HP would be linear during the flat part of the torque curve and peak where the flat part of the torque curve ends, then both the HP and Torque curves decline. It wouldn't be a bell curve.


Sunking said:


> Instead I se a pretty flat linear line that peaks at 1800 RPM @ 140 ft/lbs? Am I reading that right?


No, look at the HP at 140 ft lbs, HP is 38, then look at RPM on the RPM curve on the RPM scale where the Torque is 140 ft lbs, it's 1400 RPM.

You can get the table values on the Netgain site, also


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