Community
Search
Notices
Electric Pattern Aircraft Discuss epowered pattern aircraft in this forum

Outrunner design

Thread Tools
 
Search this Thread
 
Old 03-16-2007 | 08:27 AM
  #1  
Thread Starter
Senior Member
My Feedback: (6)
 
Joined: Jul 2002
Posts: 574
Likes: 0
Received 0 Likes on 0 Posts
From: Nineveh, IN
Default Outrunner design

Can anyone give some info on outrunner design. I understand that the less winding you have the more RPM you get, and the less torgue. But is it winding wire size that allows the motor draw more or less amps without harm to the motor? Watts are volts X amps. So if you have 37 (10s) volts X 60 amps = 2220 watts, and 2220 watts / 29.6 (8S) = 75 amps, will they be the same in efficiency.
I'm sure some will see where I'm going with this and some won't.
Thank You
Steve Maxwell
Old 03-16-2007 | 08:05 PM
  #2  
OhD
 
Joined: Oct 2002
Posts: 1,160
Received 9 Likes on 6 Posts
From: west hills, CA
Default RE: Outrunner design


ORIGINAL: patternrules

Can anyone give some info on outrunner design. I understand that the less winding you have the more RPM you get, and the less torgue. But is it winding wire size that allows the motor draw more or less amps without harm to the motor? Watts are volts X amps. So if you have 37 (10s) volts X 60 amps = 2220 watts, and 2220 watts / 29.6 (8S) = 75 amps, will they be the same in efficiency.
I'm sure some will see where I'm going with this and some won't.
Thank You
Steve Maxwell
Generally speaking, you will find that for a given power, higher voltage and lower current yields better efficiency. Low efficiency is caused by resitance in the motor, ESC and batteries, so lower current means lower voltage drop in each. So an 11s or 12s with a lower Kv motor would be more efficient. The problem is now you have heavier packs. You will also find that the current goes up pretty fast when you are trying to get another 300 rpm with a given prop. As long as we have very little margin with battery capacity and weight it becomes a tricky balancing act. We never had to worry about efficiency with glow engines, just put more fuel in the tank. However, I hear that is beginning to be a problem as the engines get bigger. Hope this helps.

Jim O

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are On



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.