rotating case motors
01-26-2005, 03:53 AM
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rotating case motors
I am a newbie at electric flight and all flight really but I am curious about rotating case motors. I recently bought a wattage crazy 8 and am going to install a motor max 400t or what i have also seen called a aurora 400t. I notice there is not to much talk on rotating case motors from what i have seen and just windering if there is a reason for that aside from the mounting problem- jeez. But ya question - are rotating case motors any good to put it bluntly.
01-26-2005, 10:44 AM
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RE: rotating case motors
The Ratating case motor is more usually known as a "brushless Out runner",which probably does not mean much to you
So! all motors come in two type,Direct current Driven or alternating current driven.However,a direct current motor(DC)has to turn the DC into Ac with a thing called a commutator.This is attached(Part of) the rotating armature u.nfortunately it Sparkes a lot ,ads weight and wastes power.
So the brushless motor was introduced(brushes are part of the commutator)This has no brushes,and is in effect an AC motor,And the DC is Turned intp AC in the special ESC for a brushless motor(which is why the are so expensive).just to make things more complicated,Brushless(BL) motors come in two types Inrunner,where the Coils are attached to to the stationary case,and the magnets(armature )rotates .
In the out runner,the magnets are attached to the case which rotates,and the coils are attached to the armature ,which stays still.So what! one may say.Well,for one thing they are easier to mke,so should be cheaper(but arent)But the main advantage is that as the rotating magnets are futher from the centre of the motor,they can exert much greater torque,which makes the motor able to turn a bigger propellor,and is therefore more powerfull,size for size,and more efficient.
Are they any good?You bet!
Avantages: Morepower,less weight,more efficient(longer motor run)
Disadvantages They can be a pain to mount,Though the later models are somewhat easier.
So! all motors come in two type,Direct current Driven or alternating current driven.However,a direct current motor(DC)has to turn the DC into Ac with a thing called a commutator.This is attached(Part of) the rotating armature u.nfortunately it Sparkes a lot ,ads weight and wastes power.
So the brushless motor was introduced(brushes are part of the commutator)This has no brushes,and is in effect an AC motor,And the DC is Turned intp AC in the special ESC for a brushless motor(which is why the are so expensive).just to make things more complicated,Brushless(BL) motors come in two types Inrunner,where the Coils are attached to to the stationary case,and the magnets(armature )rotates .
In the out runner,the magnets are attached to the case which rotates,and the coils are attached to the armature ,which stays still.So what! one may say.Well,for one thing they are easier to mke,so should be cheaper(but arent)But the main advantage is that as the rotating magnets are futher from the centre of the motor,they can exert much greater torque,which makes the motor able to turn a bigger propellor,and is therefore more powerfull,size for size,and more efficient.
Are they any good?You bet!
Avantages: Morepower,less weight,more efficient(longer motor run)
Disadvantages They can be a pain to mount,Though the later models are somewhat easier.
01-26-2005, 11:15 AM
#3
RE: rotating case motors
Since I started upgrading my electric ships to brushless power, I've bought nothing but outrunners. I have two AXIs and one PJS. So, that should tell you that at the very least, I think they're good. There may not be much talk about outrunners here, but there's plenty in the 'electric motors, gear drives, and props forum', and there's even more in the power systems forum on rcgroups.com. Look around; you'll find plenty of info, you just have to dig.
