Cold in a Can

FIRST General Forum
1

Posted by Joe Johnson.   [PICTURE: SAME | NEW | HELP]

Engineer on team #47, Chief Delphi, from Pontiac Central High School and Delphi Automotive Systems.

Posted on 12/17/99 1:31 PM MST

In my White Paper on motors, I recommend ‘Cold in a Can’ to cool motors during long practice sessions & between matches if you get to the Elimination Tournament where matches can sometimes be back to back to back to back…

Below is a link to Newark’s site where you can buy the stuff we have used for the past few years.

Highly recommended.

Joe J

2

Posted by Lora Knepper.

Student on team #69, HYPER, from Quincy Public Schools and The Gillette Company.

Posted on 12/17/99 3:21 PM MST

In Reply to: Cold in a Can posted by Joe Johnson on 12/17/99 1:31 PM MST:

My team has used that for years, and I agree that it’s a great idea to bring a supply to competition. (Especially Florida!!) There’s nothing worst than a motor stalling because of overheating…I’ve had it happen in a match during the 98 season!!

Good luck all,
Lora
Team 69 HYPER

3

Posted by Thomas A. Frank.

Engineer on team #121, The Islanders/Rhode Warrior, from Middletown (RI) High School and Naval Undersea Warfare Center.

Posted on 1/5/2000 4:06 PM MST

In Reply to: Re: Cold in a Can posted by Lora Knepper on 12/17/99 3:21 PM MST:

Hello All;

In our early years in FIRST, we used cold spray. We even used dry ice at one point. Eventually, we came to realize that if you put in proper cooling air flow, you don’t need to take these types of extreme actions, and can thus avoid the risk and bother.

Aquatread had the supplied fan blowing directly across the drivetrain motors, speed controllers, and circuit breakers - they never got hot.

RW I sucked cool air off the floor and blew it directly across the Tekin’s (remember them :-)) and the drill motors. Worked OK, but boy, did we suck up a load of crud from the carpet (we didn’t really want to be a vacuum cleaner, it just worked out that way).

RW II initially used the supplied fan to blow across the drive motors…then I saw someone at a regional using spare fans from the Victor’s (and Eric confirmed this was legal), so I replaced the large single fan with a pair of small fans to cool the drive motors. Even after an hour’s operation, they never overheated.

Now, we DID make up a small fan/battery thingy with a couple of ducts to continue blowing cooling air across the motors when we didn’t have the main battery on line…which is something I recommend to everyone. If it’s good enough for the astronauts, it’s good enough for use, right?

This year? Who knows :slight_smile:

Tom Frank

4

Posted by Eric Rasmussen.

Engineer from FIRST.

Posted on 1/10/2000 3:32 PM MST

In Reply to: Design in better cooling instead! (was Re: Cold in a Can) posted by Thomas A. Frank on 1/5/2000 4:06 PM MST:

This year we gave you not only the big muffin fan, but 3 smaller ones as well. Now it should be easier to blow air directly over the parts that need it.

-Eric

5

Posted by Joe Johnson.   [PICTURE: SAME | NEW | HELP]

Engineer on team #47, Chief Delphi, from Pontiac Central High School and Delphi Automotive Systems.

Posted on 1/10/2000 6:11 PM MST

In Reply to: Re: Design in better cooling instead! (was Re: Cold in a Can) posted by Eric Rasmussen on 1/10/2000 3:32 PM MST:

Eric,

I KNEW that you must have been talking to Tom Frank when I saw those little beauties in the kit.

Joe J.

P.S. I still would keep a can of FREEZ-IT nearby.

6

Posted by Jerry Eckert.

Engineer from Looking for a team in Raleigh, NC sponsored by New England Prototype/Brooks Automation.

Posted on 12/18/99 10:51 PM MST

In Reply to: Cold in a Can posted by Joe Johnson on 12/17/99 1:31 PM MST:

: In my White Paper on motors, I recommend ‘Cold in a Can’ to cool motors during long practice sessions & between matches if you get to the Elimination Tournament where matches can sometimes be back to back to back to back…

: Below is a link to Newark’s site where you can buy the stuff we have used for the past few years.

: Highly recommended.

Joe,

Do you apply the spray to the external housing of the motor? Or to the internal mechanisms?

In the latter case I’d be concerned about damage resulting from the sudden contraction of the hot components, especially if this technique is used frequently.

Jerry

7

Posted by Lora Knepper.

Student on team #69, HYPER, from Quincy Public Schools and The Gillette Company.

Posted on 12/19/99 7:56 AM MST

In Reply to: Re: Cold in a Can posted by Jerry Eckert on 12/18/99 10:51 PM MST:

We always applied the spray to the external housing of the motor. It works best on the drill motors that heat up quickly (especially if they are your drive train motors!). Hope that helps!

Lora Knepper
driver~team 69 HYPER

8

Posted by Joe Johnson.   [PICTURE: SAME | NEW | HELP]

Engineer on team #47, Chief Delphi, from Pontiac Central High School and Delphi Automotive Systems.

Posted on 12/19/99 7:13 PM MST

In Reply to: Re: Cold in a Can posted by Lora Knepper on 12/19/99 7:56 AM MST:

While I would like to say that we are good little boys and don’t thermal shock the snot out of those poor motors, I can’t :wink:

Basically be spray the stuff here, there, and everywhere.

For the most part we have gotten away with it.

I suppose that this is because the only time we REALLY use the stuff heavily is during the elimation rounds.

More often than not we exchange the motors (drill and Fisher-Price anyway) by the next tournament so if we don’t often get a lot of cycles on the motors after our thermal shock test.

As for the Window, Seat, Van Door, & Globe motors, we haven’t had much reason to have to change them (except for the Globe motors we toasted due to our programming mistakes),

Basically, I think that the automotive motors are pretty solid when it comes to temperature shocks.

Bottom line, I am sure that it is not good for the internals of the motors to have liquid cold stuffed sprayed on them, but, sometimes it is needed if you want to have full power in time for the next match (after all, it is the heat in the windings of the motor that is reducing the output, so the cooling is most needed inside right on the arrmature).

Even so, I don’t recommend that you kids try this at home.

Joe J.

9

Posted by Raul.

Engineer on team #111, Wildstang, from Rolling Meadows & Wheeling HS and Motorola.

Posted on 12/20/99 6:18 AM MST

In Reply to: any port in a storm posted by Joe Johnson on 12/19/99 7:13 PM MST:

: Bottom line, I am sure that it is not good for the internals of the motors to have liquid cold stuffed sprayed on them, but, sometimes it is needed if you want to have full power in time for the next match (after all, it is the heat in the windings of the motor that is reducing the output, so the cooling is most needed inside right on the arrmature).

: Joe J.

OK, I have seen studies about how thermal shock can cause damage to some PC board components, IC’s, etc. (especially surface mount). However, I have only heard rumors that thermal shocks such as those presented by inert coolants can damage other electrical components.

I understand the physics of thermal shocks and the resultant stresses induced by gradients and dissimilar materials. But, I also know that many materials are capable of withstanding these stresses in many applications.

I am a little skeptical. So, I would be curious to see if any studies have been done on motors for thermal shock. Does anyone know of a study done on this?

Raul