News:


  • March 28, 2024, 11:38:01 PM

Login with username, password and session length

Author Topic: Motor size 2320 vs 2808?  (Read 1086 times)

Offline Dennis Toth

  • 2020 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4209
Motor size 2320 vs 2808?
« on: February 12, 2021, 08:28:20 AM »
Guys,

I'm looking to save some weight and one area is the motor size. I have two choses a 2808  1100kV or a 2320 x 820kV. The 2808 is about 3/4oz lighter and would be preferred. I intend to use a 9x6 prop at 9950 rpm on a 4S pack. My question is does the can length have more impact on amps (and torque) then the diameter or vise-versa?

Best,   DennisT

Offline pmackenzie

  • Pat MacKenzie
  • 24 supporter
  • Trade Count: (0)
  • Captain
  • *
  • Posts: 765
Re: Motor size 2320 vs 2808?
« Reply #1 on: February 13, 2021, 08:16:17 AM »
What actually determine a motors torque rating is the area of the magnet gap, so length * diameter*pi.
But not the external dimensions, you need the internal ones of the core laminations.

This is sort of like the long stroke versus short stroke arguments about torque in IC engines. If you do the math all that really matters is displacement.
One dimension simply trades off with the other

« Last Edit: February 13, 2021, 08:55:51 AM by pmackenzie »
MAAC 8177

Offline TDM

  • Trade Count: (0)
  • Captain
  • *****
  • Posts: 844
Re: Motor size 2320 vs 2808?
« Reply #2 on: February 14, 2021, 08:31:14 AM »
Saving weight with a lighter motor never yields a lighter setup because you will surely pay the price downline with bigger battery and bigger ESC.
If you really want to save weight use a bigger motor and use smaller ESC and battery.
Each goal you meet is a moment of happiness
Happiness is the harmony between what you think and what you do. Mahatma Gandhi

Offline Dennis Toth

  • 2020 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4209
Re: Motor size 2320 vs 2808?
« Reply #3 on: February 14, 2021, 09:54:39 AM »
I decided to go with the BadAss 2320  820kV. I did a quick test run and it spins up smooth and hits the rpm. The BadAss motors are generally 15% lower battery draw then the cheap motors. I'm hoping it will let me drop down to a 5S 1350mah TP pack, this saves about 2oz. Test flight as soon as we get a claim day.

Best,   DennisT


Offline Dennis Toth

  • 2020 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 4209
Re: Motor size 2320 vs 2808?
« Reply #4 on: February 15, 2021, 09:33:15 AM »
Update: I flew the BadAsss 2320  820kV with the 10x6.5 APCE P, at 9950 rpm. This worked very well and had room to spare. Actually will need to de-pitch back to 6 ish as the lap time was 4.44sec on 60' c to c.

Best,  DennisT

Offline John Rist

  • 24 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 2944
Re: Motor size 2320 vs 2808?
« Reply #5 on: February 15, 2021, 04:47:26 PM »
Update: I flew the BadAsss 2320  820kV with the 10x6.5 APCE P, at 9950 rpm. This worked very well and had room to spare. Actually will need to de-pitch back to 6 ish as the lap time was 4.44sec on 60' c to c.

Best,  DennisT
Remember with electric you can drop the RPMs a little to adjust lap time.  Gives more head room for RPM control and should reduce battery usage.
John Rist
AMA 56277


Advertise Here
Tags:
 


Advertise Here