Are all Brushless motors created equal?
06-26-2007, 07:05 PM
#1
Are all Brushless motors created equal?
We are looking at the possibility of running a restricted modified using brushed OR brushless motors.
Currently we run to a 12turn limit in modified here in New Zealand and the proposal is to allow a brushless equivalent along with the brushed motors.
We know from some testing we have done with a Novak 6.5 in several cars that the times are basically exactly the same as their brushed setups.
My question is this, if other brand 6.5 motors are used are they effectively the same as the Novak motors? In other words can I use all brand 6.5 motors in a spec class and they should all thoretically be approximately the same like one brand 12T brushed motor vs another brands 12T motor?
What does the 6.5 refer to exactly?
Currently we run to a 12turn limit in modified here in New Zealand and the proposal is to allow a brushless equivalent along with the brushed motors.
We know from some testing we have done with a Novak 6.5 in several cars that the times are basically exactly the same as their brushed setups.
My question is this, if other brand 6.5 motors are used are they effectively the same as the Novak motors? In other words can I use all brand 6.5 motors in a spec class and they should all thoretically be approximately the same like one brand 12T brushed motor vs another brands 12T motor?
What does the 6.5 refer to exactly?
06-27-2007, 05:42 AM
#2
They will be approximately the same, but differences will always be present. It is just like brushed motors, company A uses this brush setup and company B uses a little different setup. The are close in performance, but one may have more top end and the other may have more torque. Not all brushless motors are exactely the same either. The 6.5 refers to the number of winds on the stator of the motor. The motors with this name will all have the same number of winds, but other things may be different like the number of wires wrapped (single, double, etc) and geometry of the core. If you really want equalized performance, you would probably have to mandate a specific motor from one manufacturer.
06-27-2007, 12:55 PM
#3
Unfortunately, there are more variables in it. The type of wind (Wye or Delta) and Composition of the Rotor (Bonded, Sintered) will play a big part in the type of power generated by a BL motor. The industry is struggling right now as a whole with how to rate them. Hopefully we will get there soon.
06-27-2007, 01:21 PM
#4
...so the long and the short of it would be - YOU can make a SPEC type MOD class, but really the only way to keep it even 'performance' wise would be to also limit the MFG. of the motor to all being 'the same'
That takes the Wye vs the DELTA winds out - you can take out Sensored vs. sensorless, etc.
IS THIS FAIR?
It depends on WHO you are trying to be fair too.
A)FAIR to the COMPETITION
B)FAIR to the COMPANY who made his product NOT FIT within a parameter that lets HIS product be used against another.
That takes the Wye vs the DELTA winds out - you can take out Sensored vs. sensorless, etc.
IS THIS FAIR?
It depends on WHO you are trying to be fair too.
A)FAIR to the COMPETITION
B)FAIR to the COMPANY who made his product NOT FIT within a parameter that lets HIS product be used against another.
06-27-2007, 01:54 PM
#5
no they are not all created equal
06-27-2007, 06:26 PM
#6
6.5 refers to the number of turns
yes novak 6.5 and lrp 6.5 is very comparable.
like all motors though, even a novak 6.5 vs another novak 6.5 will have minor differences like magnet strenght. but its really very very minimal.
more important is what batteries you have and how fresh they are.
e.g even if someone has a Novak4.5 but has old GP3300's. Then another guy has a novak 6.5 with fresh matched IB WC 4200's that are only 1 week old, the guy with the 6.5 would be much much faster than the guy with the 4.5
yes novak 6.5 and lrp 6.5 is very comparable.
like all motors though, even a novak 6.5 vs another novak 6.5 will have minor differences like magnet strenght. but its really very very minimal.
more important is what batteries you have and how fresh they are.
e.g even if someone has a Novak4.5 but has old GP3300's. Then another guy has a novak 6.5 with fresh matched IB WC 4200's that are only 1 week old, the guy with the 6.5 would be much much faster than the guy with the 4.5
06-28-2007, 02:53 AM
#7
Apparently some guy has made a little gadget that gives a reading on the strength of the magnet on the rotor from BL motors.. (check out the current episode of rctv.com) so i guess not, looks like some rotors may have stronger rotors than others.. but.. has'nt this sorta business been going on since peope started racing tamiya hornets lol.. as brushless becomes more main stream racers are always guna look for the edge... but hey.. thats racin' 
06-28-2007, 02:01 PM
#9
I think you canīt compare brushed and brushless motors as brushless always do have more power and efficiency at least as soon as youīre running sintered rotors. Also I donīt know how you want rate a certain motor. For brushed motors there are some dynos available what can help but until now there is not one single dyno available (at least not for the public) what can run brushless motors. Those meters wonīt help very much.
06-28-2007, 02:58 PM
#10
not all brushed 12turn motors are the same either, so that would be something to consider.
06-29-2007, 07:15 AM
#13
How should this work? The Fantom can generate 3-phase voltage? I donīt think so.
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