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help slapping a forum troll

Posted: Fri, 27 Jan 2012, 17:10
by Adverse Effects
hi guys can i get a hand with slapping down a forum troll pls

rogue277 has to be the most stupid guy/gal i have seen
http://www.rcgroups.com/forums/showthre ... 756&page=3

help slapping a forum troll

Posted: Fri, 27 Jan 2012, 18:13
by woody
I'm not sure who needs the slap :-)

They're coming at the problem from a practical point of view - two motors with the same Kv will have approximately the same torque at the same current.

You're coming from a theoretical point of view, a disc motor should have a lower Kv for the same weight, but who knows what manufacturers have made.

Cooling & Efficiency are probably different between the two motor designs too.

help slapping a forum troll

Posted: Fri, 27 Jan 2012, 19:57
by Adverse Effects
they are talking in relation to a multicopter where low RPM and high torque to push a big prop is needed at a slower speed not to mention you dont want your props up on high pillers at the end of each arm

help slapping a forum troll

Posted: Fri, 27 Jan 2012, 20:21
by Adverse Effects
so is this not correct?

thes are just examples

11.1VDC 10AMP in the long and narrow will spin DAM fast but have little torque (this is why they use reduction gearbox on most of them)

11.1VDC 10AMP in the short and wide will spin slow but have a dam lot of torque

trust me i am allways willing to learn when i can

help slapping a forum troll

Posted: Fri, 27 Jan 2012, 22:32
by Electrocycle
depends on the individual motor.

Most of the time a long narrow motor will have higher Kv than a short wide one, and will therefore make less torque but at more rpm, for the same voltage.

You could easily have a narrow one that makes the same torque though, and have the same Kv rating, but it will generally be a larger (and more powerful) motor.

Two motors with the same Kv and wattage rating should make the same torque / power / rpm, no matter what design they are.

help slapping a forum troll

Posted: Fri, 27 Jan 2012, 22:39
by woody
yes, that makes sense in theory, all things being equal.

But if you have two motors, but both have been tested and have the same specs, then the shape is as relevant to the performance as the colour - not very.

An analogy:
If you have two cars which have done 12 seconds for the quarter mile, you have two cars which can do 12 seconds for the quarter mile.

One may be a '64 oldsmobile toronado, one may be a '74 Mazda RX3.

In theory the mazda should be much faster at drag racing because it is lighter, narrower, and rear wheel drive, but it happens that the performance is the same, so both do 12 seconds, if that's your goal, you are happy.

help slapping a forum troll

Posted: Fri, 27 Jan 2012, 23:55
by Adverse Effects
i was going on what the hobby sites are selling as a general rule the wider the motors get the shorter they get and the lower the KV gets