# 15,000 RPM Dc motor



## epyon (Mar 20, 2008)

I would like to build a dc motor that will do high rpm's and be controlled by a 144 v controller , but all my findings lead me to a brushless motor . I think I can build a brushless motor that works with a standard controller . But I might be missing something small . Motors for toy cars and tools are getting to 40,000 rpm and living , and some of them are on the big side . I want to up the scale on the motor and go from there . I would like to give my machine shop guy some ideas for parts to make for me . The motor I have is small and I want to get bigger . If I use brushes , that's fine . I just want it to be powerful too ........ Well , 50 to 85 HP to start , 25HP if it'll turn the RPM's . I really believe this is a mechanical problem and not electronic .


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## CrazyAl (May 9, 2011)

epyon said:


> I would like to build a dc motor that will do high rpm's and be controlled by a 144 v controller , but all my findings lead me to a brushless motor . I think I can build a brushless motor that works with a standard controller . But I might be missing something small . Motors for toy cars and tools are getting to 40,000 rpm and living , and some of them are on the big side . I want to up the scale on the motor and go from there . I would like to give my machine shop guy some ideas for parts to make for me . The motor I have is small and I want to get bigger . If I use brushes , that's fine . I just want it to be powerful too ........ Well , 50 to 85 HP to start , 25HP if it'll turn the RPM's . I really believe this is a mechanical problem and not electronic .


Brushes are a wear item which means they will require replacement. At 15000RPM, I think you may encounter arcing issues, which is why brushless is a better choice.

With the toys, I know with many of the radio controller air planes, the motors are typically brushless motors.

What type of controller did you have in mind?
Controllers are typically specific to the motor type which means a controller for a Series Wound DC Motor will typically not work for a Brushless DC Motor.
With brushed motors, the brushes mechanically do the commutations.
With a brushless motor, the controller will need to do the commutations.

With Brushless DC Motors, some have sensors and some don't. If the motor has no sensor, then you require a sensorless brushless DC controller. Others have a hall sensor. There could be other types of sensors as well, but you have to get the controller that is compatible with the motor.


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## gor (Nov 25, 2009)

check "400 hz" thread on this forum - there are 400 hz light and powerful motors in aircraft and industrial equipment, 15-20 000 rpm

starting torque - low, which is fine, if used with sportsbikes (11-16000 rpm) transmission - beats ice low rpm torque (0 ) ... 

motors are simple, but controllers OEMs quote are or big, heavy and/or very expensive


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## CrazyAl (May 9, 2011)

gor said:


> check "400 hz" thread on this forum - there are 400 hz light and powerful motors in aircraft and industrial equipment, 15-20 000 rpm
> 
> starting torque - low, which is fine, if used with sportsbikes (11-16000 rpm) transmission - beats ice low rpm torque (0 ) ...
> 
> motors are simple, but controllers OEMs quote are or big, heavy and/or very expensive


Is this the thread link you were referring to? http://www.diyelectriccar.com/forums/showthread.php?t=64904&highlight=400hz

Am I seeing things or not because the inverter controller for the 150kw motor appeared to be as tall as a person. 

The motors running at those high speeds are AC (assuming they have no brushes).


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## epyon (Mar 20, 2008)

I'll check out the 440hz thread . But I was looking for a way to make the fields more in line then having the fields pushing and pulling like switches with hz style . I hope that came out clearer .


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