www.robowars.org

RoboWars Australia Forum Index -> Technical Chat

Heat sinks


Post new topic   Reply to topic
  Author    Thread
Glen
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect


 Reply with quote  
Heat sinks

Took my brushless controller apart to clean it and modify a few things - and i noticed that between the heatsink and the top of the fets is a rubber sheet isolating it from the heatsink? that shouldnt be right?

shouldnt the fet cases touch the heatsink directly to sink the heat Confused ill get a pic in a while to show you what i mean.

and on the same subject i got onto thinking - would it be better to replace the finned style heatsink with a solid piece of aluminium of the same dimensions? i mean its not like the fins can dissippate much in 3 minutes in an enclosed heater (aka robot) so would it be better to just have as much thermal mass as possible in it?
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Post Fri Nov 21, 2008 12:24 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
Nick
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW


 Reply with quote  

The rubber mat would be there if the FETs had an electrically active heatsink tab. If the ESC is using the common plastic mini package then the mat is probably just there for insurance - if something conductive got in there, it could short FET leads to the HS and cause mayhem. I'd check the FET cases and take the mat out if they are not conductive.

The HS is probably finned for lighter weight in a model plane. A bigger thermal mass would be better until it was all heated up to a critical temp. A finned HS and air flow is the best bet if you can manage it.

Post Fri Nov 21, 2008 2:25 pm 
 View user's profile Send private message
dyrodium
Experienced Roboteer


Joined: 24 Aug 2004
Posts: 6476
Location: Sydney


 Reply with quote  

Fit a fan to it like with the cyclone glen!
It could well be thermal conductive foam too. Smile
I must say I noticed it with my esc. No one's exploded a sentilon yet, so don't worry too much.
_________________
( •_•)

( •_•)>⌐■-■

(⌐■_■)

YEAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAH

Post Fri Nov 21, 2008 3:36 pm 
 View user's profile Send private message Visit poster's website MSN Messenger
Glen
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect


 Reply with quote  

yeah my concern has always been that the heatsink never heated up on mine when the motor would get seriously hot so just not thinking the heatsink was being conducted to thermally Confused but ill just leave it then if the rubber stuff is heat conductive Smile
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Post Fri Nov 21, 2008 3:42 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
DumHed
Experienced Roboteer


Joined: 29 Jun 2004
Posts: 1219
Location: Sydney


 Reply with quote  

yeah it'll be a thermally conductive mat.
They work pretty well, and are much easier than using thermal paste Smile
_________________
The Engine Whisperer - fixer of things

Post Fri Nov 21, 2008 5:24 pm 
 View user's profile Send private message Visit poster's website MSN Messenger ICQ Number
  Display posts from previous:      

Forum Jump:
Jump to:  

Post new topic   Reply to topic
Page 1 of 1


Forum Rules:
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

 

Last Thread | Next Thread  >
Powered by phpBB: © 2001 phpBB Group
millenniumFalcon Template By Vereor.