Go to Post wow!! Andy Baker really is a pig farmer!! and all this time i thought that paul copioli was stereotyping! - RogerR [more]
Home
Go Back   Chief Delphi > Technical > Motors
CD-Media   CD-Spy  
portal register members calendar search Today's Posts Mark Forums Read FAQ rules

 
Closed Thread
Thread Tools Rating: Thread Rating: 4 votes, 4.50 average. Display Modes
  #16   Spotlight this post!  
Unread 20-02-2014, 10:49
ausinhanks ausinhanks is offline
Registered User
FRC #7198
 
Join Date: Sep 2013
Location: washington
Posts: 1
ausinhanks is an unknown quantity at this point
Re: Is the CIM COOLER Good for use?

we are looking for more of these sim coolers and i was wondering if anyone knew where to buy them thanks
  #17   Spotlight this post!  
Unread 20-02-2014, 12:13
Robo Hamsters Robo Hamsters is offline
Registered User
AKA: Matthew Vesperman
FRC #4466 (Robo Hamsters)
Team Role: Mentor
 
Join Date: Dec 2012
Rookie Year: 2012
Location: Culpeper, Va.
Posts: 89
Robo Hamsters is on a distinguished road
Re: Is the CIM COOLER Good for use?

Quote:
Originally Posted by ausinhanks View Post
we are looking for more of these sim coolers and i was wondering if anyone knew where to buy them thanks
http://store.nextgenrobots.com/product/cim-cooler-360
__________________

FRC 4466
FTC 7042
=================
2013 Washington DC Regional Finalist
  #18   Spotlight this post!  
Unread 20-02-2014, 12:21
MrForbes's Avatar
MrForbes MrForbes is offline
Registered User
AKA: Jim
FRC #1726 (N.E.R.D.S.)
Team Role: Mentor
 
Join Date: Feb 2006
Rookie Year: 2006
Location: Sierra Vista AZ
Posts: 6,033
MrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond reputeMrForbes has a reputation beyond repute
Re: Is the CIM COOLER Good for use?

We switched to the little Viair compressor this year, and like many other teams added a big fan to keep it cool. Since the compressor is in the middle of our robot, between the drive motors, it also happens to keep the outside of the drive motors cool. No heat sink required.

Your mileage may vary.
Attached Thumbnails
Click image for larger version

Name:	fan.jpg
Views:	79
Size:	749.9 KB
ID:	16340  
  #19   Spotlight this post!  
Unread 20-02-2014, 12:56
Jarren Harkema's Avatar
Jarren Harkema Jarren Harkema is offline
Dancing Drive Coach
FRC #4967 (That ONE Team)
Team Role: Mentor
 
Join Date: Sep 2013
Rookie Year: 2013
Location: Michigan
Posts: 167
Jarren Harkema is a name known to allJarren Harkema is a name known to allJarren Harkema is a name known to allJarren Harkema is a name known to allJarren Harkema is a name known to allJarren Harkema is a name known to all
Re: Is the CIM COOLER Good for use?

Quote:
Originally Posted by MrForbes View Post
We switched to the little Viair compressor this year, and like many other teams added a big fan to keep it cool. Since the compressor is in the middle of our robot, between the drive motors, it also happens to keep the outside of the drive motors cool. No heat sink required.

Your mileage may vary.
Same sort of set up for us as well. We are using a server fan which blow air across the compressor and cims on the left side. This worked so well we mounted a second fan on the the other side to keep the right coms cool.
  #20   Spotlight this post!  
Unread 20-02-2014, 13:29
Mason987 Mason987 is offline
President
FRC #0987 (High Rollers)
Team Role: CAD
 
Join Date: Sep 2012
Rookie Year: 2012
Location: Las Vegas
Posts: 39
Mason987 is an unknown quantity at this point
Re: Is the CIM COOLER Good for use?

Quote:
Originally Posted by Doc Wu View Post
If I were going to install them on a CIM motor, I would use a heat sink compound, much like the heat sink on a CPU or transistor. The paint on the case would be a consideration as well, but with the narrow views of what is considered a "modification" in the rules, I'd be afraid removing paint might be a problem. Even the silicone compound might get questioned.
I'm not 100%, but i was looking at the bag those heat sinks come in and they suggest using a compound themselves. We aren't using them so we won't run into this problem but I would imagine some thermal paste on them would be acceptable. Without the paste, the aluminum isn't transferring the heat as well, obviously enough. I'd imagine driving around and letting the air do the cooling might even be more beneficial than a heat sink without the thermal paste.

I could be wrong though.
  #21   Spotlight this post!  
Unread 20-02-2014, 13:39
Nathan Streeter's Avatar
Nathan Streeter Nathan Streeter is offline
FIRST Fan(atic)
FRC #1519 (Mechanical MAYHEM)
Team Role: Mentor
 
Join Date: Feb 2008
Rookie Year: 2006
Location: Merrimack, NH
Posts: 676
Nathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond reputeNathan Streeter has a reputation beyond repute
Re: Is the CIM COOLER Good for use?

As has been mentioned by Andrew Palardy and others, a heat sink will probably have relatively little impact on the motor winding temperature over the course of a 2-3 minute match... See Richard Wallace's data for evidence regarding that (note how, during the test, the motor case temp only rises by about 5-10degC).

Where I do think a heat sink would make a difference - and I think it would - is when you put the usage in the context of practice, elim matches, or short match-turn-around (i.e. districts or off-season), etc. The internals of the motor can't be cooled below the CIM case temperature... so as the external motor housing climbs to higher temperatures, so also do the minimum and working internal temps (since under same power output conditions, the same deltaT will be maintained from motor windings to CIM case).*

So, I definitely recommend that teams consider how to cool their CIMs! I know I'd like to work out a way to put a heat sink solution on our robot!

I haven't used the CIM COOLERS but they look like a neat solution... I do have a few comments about them though:

-The linked video test is neat, but running at free speed is fairly low heat output (32W)... At max power they dissipate 477W, and at stall they dissipate a mind-blowing 1596W**! At only 32W, simply adding aluminum to the case to hold more heat for a given temp increase would have a beneficial impact.

-Heat sinks rely on air taking the heat away... hence the fins. Without a fan (forced convection), it relies simply on the air moving around... which is driven by the fact that air becomes lighter when it gets hotter. In the test the fins are vertical (ideal), while on almost all robots they are at all angles (vertical, horizontal, upside-down)... this means its effectiveness will be significantly lower when mounted horizontally, particularly in a cramped robot.

- If teams use the heat sinks, they should definitely apply thermal paste (I've had experience with silicone grease and other gap fillers... i.e. http://www.bergquistcompany.com/ther...roperties.htm). Interfaces are tremendous thermal insulators... applying a little thermal paste and then bolting the heat sinks together firmly enough so that paste squeezes out will help tremendously. With many Watts being dumped through that interface, you could have a huge thermal rise just in the interface (let alone the motor internals). I wouldn't be surprised if using the CIM COOLER with no thermal compound gives little or no benefit. If you do use a thermal paste, I highly recommend the blue stuff from Bergquist... compared to grease it's extremely easy to cleanup!
So, I would recommend investigating a CIM-cooling solution... but putting some big muffin fans on there to run while the robot's on or off may go about as far (note, the robot's usually on the cart far more than it is powered on). You'll likely want fans somewhere to force the air around, rather than relying on free convection.

*If you're interested in a tidbit about heat transfer... it works the same way electricity does. In electricity, a Voltage drop (i.e. deltaV between two battery terminals) drives/pushes electrical current (I) to move against electrical resistance (R). Similarly, a Temperature drop (i.e. deltaT between CIM internal and CIM case, then between CIM case and ambient) drives heat to move against thermal resistance.

** Note, 1596W is nearly as much as an oven puts out, and well over that of a microwave! Now that certainly motivates me to cool my CIMs and avoid stalling them!
__________________
"If you want to build a ship, don't drum up men to gather wood, divide the work, or give orders. Instead, teach them to yearn for the vast and endless sea." - Antoine de Saint-Exupery
"The fight is won or lost far away from witnesses - behind the lines, in the gym, and out there on the road, long before I dance under those lights." - Muhammad Ali
"Simplicity is the ultimate sophistication." - Leonardo da Vinci


Student: 2006-2010 (#1519)
Mentor: 2011-Present (#1519)


Closed Thread


Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 15:28.

The Chief Delphi Forums are sponsored by Innovation First International, Inc.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright © Chief Delphi