Power Systems Talk about motors, ESC speed controllers, gear drives, propellers, power system simulators and all power system related topics

Watts in an ESC

Old 12-11-2018, 10:21 PM
  #1  
Jack_Hammer
Veteran USAF
Thread Starter
 
Jack_Hammer's Avatar
 
Join Date: Oct 2018
Posts: 69
Default Watts in an ESC

Catchy title huh?

A neighbor brought me a 30a esc with the plastic wrap removed (I didn't ask why. Too late)
an he was curious what the metal plates were for as well as the white goop under it.

I wasn't 100 percent sure, but I thought it was for cooling. Sort of like a heat sink with cooling fins only the fins aren't necessary. The goop simply distributes cooling at the point of contact on the circuitry and more evenly.

But I told him to know for sure it's best to ask the knowledge base here on WattFlyer.

Is this ESC now rendered unusable?
Attached Images
File Type: jpg
20181211_160848.jpg (2.91 MB, 141 views)
File Type: jpg
20181211_160924.jpg (2.60 MB, 105 views)
Jack_Hammer is offline  
Old 12-11-2018, 11:16 PM
  #2  
hayofstacks
Super Contributor
 
hayofstacks's Avatar
 
Join Date: Jan 2012
Location: Utah
Posts: 1,780
Default

The metal plate is a heat sink, and the goop is thermal paste.

Should be pretty much the same stuff they use for computer cooling stuff. The plastic holds the plate on. I have put heatshrink on top of esc's before. I would try to leave some of the heat sink open to air, just to help with cooling.

Throw it back together, make sure it still works, and let it rip.
hayofstacks is offline  
Old 12-11-2018, 11:24 PM
  #3  
Jack_Hammer
Veteran USAF
Thread Starter
 
Jack_Hammer's Avatar
 
Join Date: Oct 2018
Posts: 69
Default

Originally Posted by hayofstacks View Post
The metal plate is a heat sink, and the goop is thermal paste.

Should be pretty much the same stuff they use for computer cooling stuff. The plastic holds the plate on. I have put heatshrink on top of esc's before. I would try to leave some of the heat sink open to air, just to help with cooling.

Throw it back together, make sure it still works, and let it rip.
Thanks, like I said, I had a good guess here. I've been out of the loop in the hobby for awhile. Things have changed. He says it works fine. I'll wrap it up as you described and hope he doesn't come back to get it
Jack_Hammer is offline  
Old 12-12-2018, 02:14 PM
  #4  
solentlife
Super Contributor
 
solentlife's Avatar
 
Join Date: Oct 2010
Location: Ex UK Brit now in Latvia west coast - Ventspils
Posts: 12,336
Default

Its a good trick actually to cut way a square of the heatshrink that is over that plate to let it pass heat better.

The plate of course being flat leads to many people fixing the ESC in place with double side tape using that flat plate - WRONG !! That plate should be the side that is not taped to the model ... One day ESC's will have flat fixing side as well !!

Nigel
solentlife is offline  
Old 12-26-2018, 01:46 AM
  #5  
dereckbc
Super Contributor
 
Join Date: Jun 2013
Posts: 1,220
Default

The plastic wrap as you call it does two things.



1. Holds the heat sink to the ESC.
2. Electrical insulation.


Cut it off and use tie wraps to secure heat sink, and ensure it does not make electrical contact with anything. It will run cooler which is a good thing.
dereckbc is offline  
Old 12-26-2018, 05:24 PM
  #6  
ron_van_sommeren
homo ludens modelisticus
 
ron_van_sommeren's Avatar
 
Join Date: Jul 2005
Location: near Nijmegen, Nederland
Posts: 1,109
Default

Originally Posted by hayofstacks View Post
The metal plate is a heat sink, and the goop is thermal paste. ...
And as usual way too much thermal paste because the manufacturer cannot be bothered to install the FETs correctly. I.e. same height and in same plane.
Thermal paste conducts heat better than air, but compared to aluminium it is a rather poor heat conductor.

Sand components on flat sandpaper, the surfaces of the FETs must have same height and their top surfaces must be in same plane. End with fine sandpaper. Apply paste to components and to heat sink. Scrape all excess paste off with credit card, there should only be paste in the (micro)pores. Install heatsink again.

Last edited by ron_van_sommeren; 12-27-2018 at 11:20 AM.
ron_van_sommeren is offline  
Old 12-27-2018, 12:26 AM
  #7  
quorneng
Super Contributor
 
quorneng's Avatar
 
Join Date: Jul 2008
Location: Cheshire, UK
Posts: 1,858
Default

In my view the shrink wrap does a good job of thermally insulating the ESC.
This tends to mean the heat sink is just that, it absorbs the heat from the component hot spots and distributes it away into the aluminium. The thick shrink wrap means very little heat is then transferred to the outside air.
For a normal duration electric flight it is likely stopped before the heat sink gets so hot that it is no longer absorbing any further heat.

Now if you replace the flat plate with a finned (or better still fingered) heat sink placed directly in the air flow then a steady state is reached (the ESC never gets any hotter) with only a modest temperature difference.

The fingered heat sink on my EDF Fairey Delta 2.
Name:  ESCfingers.jpg
Views: 55
Size:  132.6 KB
The heat transfer is so good that if flown on really cold days the ESC fins are at ambient by the time you reach the plane but the same could not be said for the EDF motor!
quorneng is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
CHELLIE
Hi-Performance and Sailplanes
2014
02-25-2018 12:51 PM
AEAJR
Beginners
165
06-28-2017 05:22 PM
AEAJR
General Electric Discussions
273
01-09-2017 03:23 AM
Wildflyer
Power Systems
15
04-14-2013 08:32 AM
kyleservicetech
Power Systems
11
09-06-2011 06:19 AM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
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 On


Quick Reply: Watts in an ESC


Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.

Page generated in 0.09577 seconds with 18 queries