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cowboysir
2014.10.01, 09:59 AM
I'm curious to find out if swapping the rotors (available seperate) in certain KV motors would change the overall KV?

For example, if I put a thinner rotor in a 5500kv motor would it then rotate to the same KV as a 7500?

Thanks for your time.

cowboysir
2014.10.10, 11:43 PM
Still curious to find out more about these replacable rotors:

1.I don't want to assume but in theory I see each motor built to a specific wiring layout and built with a standard 14.5mm rotor to get the KV ratings of 5500, 7500 and 9500.

So if i put 2 and 2 together and install a 15.5mm rotor into a 5500kv can with windings I would get a lower kv overall and more low end?

anyone got the skinny on this ?

Felix2010
2014.10.11, 10:49 PM
It only makes sense that swapping a smaller or larger diameter rotor into a brushless motor will change the Kv/RPM's --- The same way that swapping the armature or magnets in a brushed-type motor changes the overall RPM's of the motor, in addition to altering the torque output of the motor.

cowboysir
2014.10.11, 10:55 PM
True enough if I knew exactly which rotor came in which can. I'd like to get a 5500 but don't want to blow another $15 if it comes equipped with the 15.5mm rotor

Felix2010
2014.10.11, 11:52 PM
Ahh.. I see your point cowboysir... :confused:

Maybe email Philip @PN and ask him what size rotors come with the 3 different Kv PN V2 Brushless motors???

I also think it would be good to know whether the 5500 7500 9500 motors all come with 14.5mm rotors...

Rune
2014.10.29, 05:52 PM
All V2's are delivered with 14,5mm rotor :)

cowboysir
2014.10.29, 06:41 PM
Excellent news Rune! I appreciate it...:D

Looks like I may try again with the VE.;)

TheSteve
2014.10.29, 07:13 PM
Excellent news Rune! I appreciate it...:D

Looks like I may try again with the VE.;)

Yeah, like you need more motor...

Racer-HH
2014.11.23, 01:15 PM
Do you need to shim the other armatures differently from the standard 14,5 rotor?

cowboysir
2017.08.01, 09:05 AM
Still curious to find out more about these replacable rotors:

1.I don't want to assume but in theory I see each motor built to a specific wiring layout and built with a standard 14.5mm rotor to get the KV ratings of 5500, 7500 and 9500.

So if i put 2 and 2 together and install a 15.5mm rotor into a 5500kv can with windings I would get a lower kv overall and more low end?

anyone got the skinny on this ?

Thought I'd bump this up to see if anyone has data.... I've been almost curious enough to get a brushless motor checker and put together some data on rotor swaps in various PN brushless V2.

Chime in if you have physical test results?

yasuji
2017.08.04, 12:11 PM
Thought I'd bump this up to see if anyone has data.... I've been almost curious enough to get a brushless motor checker and put together some data on rotor swaps in various PN brushless V2.

Chime in if you have physical test results?

If i remember correctly it is approximately 1000 kv per mm
I have tested with std 14.5 an 13.5 12.5 and 15.5 in 5500kv as well as 7500 using lithium and 9500 nimh
The one thing that I noticed is that the smaller rotor is less punchy with more rip to the peak
For the most part it us a good set if tools to have in the arsenal to fine tune the charectisic for your driving style
For me... on the 9500 nimh I prefer the 13.5 rotor
For 5500 lithium 12.5 or 13.5
For 7500 lithium 14.5 std
Hope this helps

cowboysir
2017.08.04, 08:54 PM
thanks Grant... that's some of the information I was hoping to find.

I'm not much for li-po racing at this scale so I think I've got some testing to do at 4.8v.

yasuji
2017.08.05, 02:30 AM
thanks Grant... that's some of the information I was hoping to find.

I'm not much for li-po racing at this scale so I think I've got some testing to do at 4.8v.

The newest thing we have been doing at kenon is 5500kv nimh vs 3500kv lithium.... cars are about even with open gearing

EMU
2017.08.17, 11:19 PM
Grant, how does the change in rotor effect the off throttle characteristic? Does the increase in mass moving to a larger rotor decrease the drag brake and vice versa?

Been a while since I've played mini-z, thinking of finally building up my brushless car...

yasuji
2017.08.17, 11:26 PM
Grant, how does the change in rotor effect the off throttle characteristic? Does the increase in mass moving to a larger rotor decrease the drag brake and vice versa?

Been a while since I've played mini-z, thinking of finally building up my brushless car...

Bigger magnet more torqe and slightly more drag brake smaller magnet less punch smmth rip to the top:)

EMU
2017.08.18, 01:46 AM
Bigger magnet more torqe and slightly more drag brake smaller magnet less punch smmth rip to the top:)
Thanks for the info. :D I will be looking into getting the biggest magnet I can ;) I like my low end punch and higher drag brake...

Have to decide whether I'm going Lipo or nimh before choosing the motor.

cowboysir
2017.08.19, 11:07 AM
Thanks for the info. :D I will be looking into getting the biggest magnet I can ;) I like my low end punch and higher drag brake...

Have to decide whether I'm going Lipo or nimh before choosing the motor.

Based on Grants info I've been working on a PN 7500 with a 15.5 rotor on the recommended ratio for the 7500 and I've been super happy with it's feel and performance on 4.8v.

I haven't done any recorded testing but I think I've devised
A work around for my brushed motor tester.