

Sep 14, 2009, 07:55 PM  
USA, NC, Hendersonville
Joined Jul 2005
787 Posts

guys, this looks like graduate level formula talk how about a simple formula to work with since most of the data bases are way out of date.
Very simply, I have a 2505 ... 12 poles/14 magnets ... I'll wind dlrk. I want to turn a 10" SF GWS prop on 2 cells, on a 10 oz 3D foamy. I'd like around 10 amps. In my mind a formula would be # of turns ... awg wire ... and termination. Now that would be a formula I could get my mind around and use. Any help ... please 
Oct 17, 2009, 04:47 PM  

People are always asking about turns and Kv. Here's the equation that relates # of turns (Tx) and Kv (Kvx) for a given motor and termination:
Kv1*T1 = Kv2*T2 = Kv3*T3 =...= Kvx*Tx = Constant Some common simplifications used by those who rewind motors: T2 = Kv1*T1/Kv2 Kv2 = Kv1*T1/T2 ...and to be sure, the constant is different for different motors. Different magnet numbers count as different motors here. Different terminations can be related with the root(3) rule, which relates delta Kv to Y Kv. The root(3) rule is already listed in the first post. Cheers, Kev 
Oct 30, 2009, 05:39 PM  

Quote:
If you mean true LRK 6 coils (on 12 slots) with 14 magnets (14 poles) steel ring Scheme AbCaBc Delta connecting I would say Kv roughly 2000 rpm/V for 2208 stator size But the real world Kv depends also of magnet total volume and airgap if you mean dLRK 18 turns per tooth (36 wires per slot) Kv around 1000 Louis 

Nov 01, 2010, 12:42 PM  
Joined Oct 2010
4 Posts

Quote:


Nov 02, 2010, 12:30 AM  

T is the number of electromagnetically effective turns wound around each stator pole. For example, a multistrand wind with 3 parallel strands may physically have 36 turns of copper on each stator pole, but you would use 12 turns in the equation (to be consistent with EM theory). Same rule counts for half parallel and full parallel winds. Physical turns equals effective turns for a standard wind.
Kv is the specific speed constant of the motor (in RPM/V). One of the three fundamental constants that define motor performance. Kev 
Dec 04, 2010, 02:41 PM  

Quote:
Try free Scorpion Calc here http://www.rcgroups.com/forums/showthread.php?t=736782 Louis 

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