Results 1 to 13 of 13

Thread: Large Electric motors vs Smaller Electric motors

  1. #1
    Join Date
    Mar 2017
    Location
    VI
    Posts
    371

    Default Large Electric motors vs Smaller Electric motors

    I have been fortunate to do some datalogs of 2 leopard 4092, and leopard 4074. I have done datalogs with other sizes too.

    What I have learned is the rpm difference between the two size motors are very small underload. And I refer to loads over 150amps for a 2080kv on 4s and for the around 1750 ish kV around 115 plus amps on 4s.

    Where the bigger motor stands out is the ability to discipate heat. And there can handle more input power without heating issues.

  2. #2
    Join Date
    Feb 2008
    Location
    GB
    Posts
    2,726

    Default

    No Ship Sherlock.
    Paul Upton-Taylor, Greased Weasel Racing.

  3. #3
    Join Date
    Apr 2007
    Location
    AZ
    Posts
    8,009

    Default

    That isn’t much of a load. It is more than just heat issues. The larger motor will handle significantly more amps before the coils will become saturated. This means that the smaller motor will convert the excess amps into heat, while the larger will convert that energy into rotational power. Big difference, why do you think they make larger motors with larger coils instead of just making the smaller motors heavier to dissipate heat better?
    ERROR 403 - This is not the page you are looking for


  4. #4
    Join Date
    Apr 2017
    Location
    QL
    Posts
    1,038

    Default

    lets say a 4092 with 2000 kvs will produce more torque than a 4072 with 2000 kv,s. bigger can more torque bigger prop.

  5. #5
    Join Date
    Mar 2017
    Location
    VI
    Posts
    371

    Default

    I have an experience where a 3674 I found hold the rpm better than a 4092.

    I did a datalogs with a 4092 2080kv on 4s with a x642. Ampdraw was between 67 to 107 amps, rpm was peaking at 26400 rpm.

    What I found interesting is I have ran a 3674 2200 leopard and am seeing almost 4 mph faster in the same boat, same prop, same ESC and same battery as what I attained with the 4092 2080kv.

  6. #6
    Join Date
    Apr 2017
    Location
    QL
    Posts
    1,038

    Default

    well firstly the 40 mm motor has 2080 kv,s as opposed to the 36 mm motor having 2200 kv,s this equals more motor rpms so with a suitable prop of a small size which won,t over load the 36 mm motor such as the 642, i would think the 2200 would provide higher rpms. the 4092 / 2080 will provide alot more torque than the 3674 / 2200 though.

  7. #7
    Join Date
    Aug 2008
    Location
    CO
    Posts
    7,080

    Default

    And hull type and weight?
    "Look good doin' it"
    See the fleet

  8. #8
    Join Date
    Oct 2009
    Location
    FR
    Posts
    2,094

    Default

    Short can is better for high RPM

    Long can is better for high torque

  9. #9
    Join Date
    Dec 2009
    Location
    LO
    Posts
    30

    Default

    Quote Originally Posted by Alfa Spirit View Post
    Short can is better for high RPM

    Long can is better for high torque
    LOL !!!!

    You don't talk about motor diameter !!! Have you any experience about it ?
    And how about your soldering problem ? Does it solved ?
    On e day you will run on the water my friend... one day.

  10. #10
    Join Date
    Apr 2017
    Location
    QL
    Posts
    1,038

    Default

    Motor diameter has a big part in electric motors. an example ; you wouldn,t us a 36 mm motor in a boat thats more suited to a 40 mm motor due to size and weight of the hull.

  11. #11
    Join Date
    Mar 2017
    Location
    VI
    Posts
    371

    Default

    I actual have experience with diameter too.

    I would say in my experience, the motor design have a bigger impact on performance than can size at least 3674 to 4092.

    When I say design I mean 6 pole, 4 pole 6 slot, 4 pole 12 slot, 2 pole and so on.

    My experience has shown me magnetic strength, and metal mass can not predict which motor will be faster.

    I have experience that weaker magnets, and less metal can be more efficient and powerful in some cases.

    But like I said larger motors can handle higher power input and discipate heat better, than the smaller motor.

  12. #12
    Join Date
    Mar 2017
    Location
    VI
    Posts
    371

    Default

    After doing more data analysis with different size props.

    What I have noticed is the bigger motor retains it rpm better when going to bigger props.

    The same can be said about stronger magnets, they allow the motor to hold rpm better with bigger props.

  13. #13
    Join Date
    Apr 2007
    Location
    AZ
    Posts
    8,009

    Default

    See post #2....
    ERROR 403 - This is not the page you are looking for


Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •