Brushed/Brushless motors, speed controls, gear drives Discuss all aspects of brushless motors, brushed motors, speed controls (ESC's), gear drives and propellers in this forum.

Smoking a brushless motor???

Old 12-19-2006, 04:52 PM
Senior Member
Thread Starter
patnchris's Avatar
Join Date: Jul 2006
Location: Gurnee, IL
Posts: 1,516
Likes: 0
Received 0 Likes on 0 Posts
Default Smoking a brushless motor???

I have heard a lot of guys talking about burning up brushless outrunners.....This confuses me.....I can understand if one is running too large a prop, or too much pitch....That makes sense.....but in most cases the prop diameter is limited by ground clearance.
I guess I should get to the point....I have a plane that needs more power. I am very close to what is spec'd to max continuous amps....running a 10 X 4.7 slo flyer prop.....I can go with a slightly larger motor, but am limited on prop diameter. The issue is the weight of the plane, not the speed. So with this larger motor, how can I transfer the added power...
I know I'm not making a lot off sense, as I reread what I'm typing....So let me try and explain another way.....The plane needs more power, not speed. Is there a way to do this without going to a larger diameter prop....
This may not even be an issue, as I'm going to try the 10X4.7 with the larger motor, first....thinking that the weight of the plane, trying to take off, was lugging to original motor. the new motor has similar KV rating, but will draw a few more amps, increasing my wattage by about 50 watts....
Sorry for the rambling.....but I would gladly overtax my motor for a few seconds to get the bird in the air, if I could figure out a way to do it. Batteries don't seem to change the static wattage as I tried it with 2 different Thunder power 3 cells one 1320 ma and one 2100 ma. and got the same static readings..How does one crank up one of these things to the point where it will get hot enough to burn up..
Old 12-19-2006, 05:39 PM
Senior Member
coolbean's Avatar
Join Date: Jul 2005
Location: liberty, MO
Posts: 1,079
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Smoking a brushless motor???

To get more thust you can do 3 things
Add rpms,
Add prop length
add pitch.

The best way to add more static thrust is to add length, but you are limited my ground clearance.... Consider a 3 bladed prop.
The next thing you can do is add rpms.. this means you need more voltage. Go to a 4 cell battery and i'm sure it will pull really well... for the few seconds it takes to burn up your motor.
And finally you can add pitch... while pitch does increase the speed (maybe.. if you are pushing your motors limits your rpms will drop and your pitch speed will drop, in which case you don't get much more trust either.. all you are doing is pulling more amps and draining your battery faster) but it will add more thrust.

So My suggestion would be to go to a 3 bladed prop if you really want to push your current motor. Or get a new motor with a higher KV rating to add rpms.
Old 12-19-2006, 05:57 PM
Senior Member
Fliprob17's Avatar
Join Date: May 2006
Location: Rancho Santa Margarita, CA
Posts: 1,590
Likes: 0
Received 0 Likes on 0 Posts
Default RE: Smoking a brushless motor???

Adding pitch to the prop is the best way I have found to do it. You can keep a 10" length, but try a 6 or 7 pitch. Tons more thrust. If your motor does have the room amps wise, it will work. Otherwise as coolbean stated, it will just drain your battery faster without really doing anything. I have tried going 3 blade, unless you have a ton of rpm's to play with, it will actually slow the plane down while in flight. You will get more thrust at the same throttle setting, and actually take off quicker, but at full throttle, for speed, you are better off with a 2 blader.

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

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell or Share My Personal Information -

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.