Go Back   RCCrawler Forums > RCCrawler General Tech > Electronics
Loading

Notices

Thread: Hitec 5995tg Robot Servo Fix - Help save your robot servo from overheating

Reply
 
LinkBack Thread Tools Display Modes
Old 10-01-2006, 07:44 PM   #1
The Wheels Keep Turning
 
kevinlongisland's Avatar
 
Join Date: Jan 2004
Location: Phoenix, Arizona
Posts: 2,831
Default Hitec 5995tg Robot Servo Fix - Help save your robot servo from overheating

I've had two 5995tg robot servos overheat and fail on me during the peak of the Arizona heat. On both occasions the servos failed when used under continuous use. What I mean by continuous use is running complete battery packs down, putting in another battery pack, and crawling again. In comparison, my robot servos lasted for over a year when only being used for competition. During competition I only run about 1/2 a battery pack down, then the truck sits for at least 15 minutes or more.

There may have been more than one failure mode on the servo, but from the pictures you can see an obvious failure point. The semiconductor device on the open face of the board failed. After replacing the servo I noticed the new servo got very hot around this area. This semiconductor does not have a good path for heat to conduct away.

After analyzing the problem I came up with the following solution. An electrically non-conductive thermal transfer compound would help draw heat away from the semiconductor device and into it's surrounding components and the case (and into the atmosphere). You can purchase thermal transfer compound from most electronic outlets. This compound is often used on computer CPU's to help transfer heat. I've tested this with good results, although further testing is needed.

The first two photos show a servo that has failed. The following photos show my application of the thermal transfer compound. Put enough thermal transfer compound on the board to contact the back cover when you re-install it. That's it. The compound will help transfer heat away from this critical component and hopefully stop your servo from failing.
Attached Images
     

Last edited by kevinlongisland; 10-01-2006 at 07:46 PM.
kevinlongisland is offline   Reply With Quote
Sponsored Links
Old 10-01-2006, 07:48 PM   #2
The Wheels Keep Turning
 
kevinlongisland's Avatar
 
Join Date: Jan 2004
Location: Phoenix, Arizona
Posts: 2,831
Default

Shot of a good circuit board:
Attached Images
 
kevinlongisland is offline   Reply With Quote
Old 10-01-2006, 08:00 PM   #3
I wanna be Dave
 
SVEN's Avatar
 
Join Date: Feb 2005
Location: Burnsville
Posts: 3,096
Default

Great information, thanks. I have been running my truck only during comps so far (with the 5995's), but now that the season is over I will probably be driving a little different.

Does the compound become hard like silicon rubber, or will it remain in a liquid type state? Just wondering if I will need to put the servo back together in a certain time frame.
SVEN is offline   Reply With Quote
Old 10-01-2006, 08:30 PM   #4
The Wheels Keep Turning
 
kevinlongisland's Avatar
 
Join Date: Jan 2004
Location: Phoenix, Arizona
Posts: 2,831
Default

The compound does not dry while you are applying it. You do not have to hurry to get the cover back on.

http://www.arcticsilver.com/arctic_alumina.htm

Controlled triple phase viscosity:
Arctic Alumina does not contain any silicone. The suspension fluid is a proprietary mixture of advanced polysynthetic oils that work together to provide three distinctive functional phases. As it comes from the tube, Arctic Alumina's consistency is engineered for easy application in a thin even layer. During the CPU's initial use, the compound thins out to enhance the filling of the microscopic valleys and ensure the best physical contact between the heatsink and the CPU core. Then the compound thickens slightly over the next 50 to 200 hours of use to its final consistency designed for long-term stability.
kevinlongisland is offline   Reply With Quote
Old 10-01-2006, 09:04 PM   #5
Quarry Creeper
 
Link's Avatar
 
Join Date: Jul 2006
Location: N. Phoenix
Posts: 440
Default

Stuff like that happens out here when your thermometer looks like this,
Attached Images
 
Link is offline   Reply With Quote
Old 10-01-2006, 09:35 PM   #6
I wanna be Dave
 
Join Date: Jan 2004
Location: Austin Texas
Posts: 3,800
Default

120K? Must be a rotary....







Highmark is online now   Reply With Quote
Old 10-01-2006, 09:54 PM   #7
I wanna be Dave
 
Join Date: Mar 2006
Location: One Legend.
Posts: 2,134
Default

Great Idea!

Just be carefull that you use a high quality, NON-CONDUCTIVE & NON-CAPACITIVE product... or your fix will not work so well.

Kevin posted a product that fits that bill, don't think you can use any old thermal paste and it will work with the same results!
Unholy is offline   Reply With Quote
Old 10-02-2006, 12:12 PM   #8
Pebble Pounder
 
Join Date: Jun 2006
Location: Tampa, Fl
Posts: 135
Default

Quote:
Originally Posted by Highmark
120K? Must be a rotary....









yep 12,500 all day
_Jason_ is offline   Reply With Quote
Old 10-02-2006, 04:27 PM   #9
MODERATOR™
 
EeePee's Avatar
 
Join Date: Jul 2004
Location: Ohio
Posts: 18,927
Default

What about then sticking a heatsink on the back of the servo case?
EeePee is offline   Reply With Quote
Old 10-02-2006, 06:24 PM   #10
The Wheels Keep Turning
 
kevinlongisland's Avatar
 
Join Date: Jan 2004
Location: Phoenix, Arizona
Posts: 2,831
Default

Quote:
Originally Posted by EeePee
What about then sticking a heatsink on the back of the servo case?
That would further increase heat dissipation into the atmosphere. But today's semiconductors are made to run at really high temperatures. If the heat transfer compound solves the problem it wouldn't be worth it putting a heat-sink on the back cover.
kevinlongisland is offline   Reply With Quote
Old 10-02-2006, 07:59 PM   #11
MODERATOR™
 
EeePee's Avatar
 
Join Date: Jul 2004
Location: Ohio
Posts: 18,927
Default

Are you making that up?
EeePee is offline   Reply With Quote
Old 10-02-2006, 08:02 PM   #12
666
MODERHATER™
 
666's Avatar
 
Join Date: Nov 2005
Location: Colorado
Posts: 10,939
Default

What did you do to repair the burned up servo? I have 2 5995's like that, but my 5955's never burn up?
666 is offline   Reply With Quote
Old 10-02-2006, 08:59 PM   #13
Quarry Creeper
 
Link's Avatar
 
Join Date: Jul 2006
Location: N. Phoenix
Posts: 440
Default

Quote:
Originally Posted by Highmark
120K? Must be a rotary....








No that would be 120F in the shade.
Link is offline   Reply With Quote
Old 10-02-2006, 09:28 PM   #14
06 Super National Champ
 
JasonInAugusta's Avatar
 
Join Date: Jun 2004
Location: Stark Industries Bar and Grill
Posts: 11,361
Default

A pair of 94359Zs would fix that too! ;)

TXT-666, you don't repair them, the FETs are gone. You can send'm to hitec for repair.

Heat is the absolute enemy of a semiconductor...
JasonInAugusta is offline   Reply With Quote
Old 10-03-2006, 10:03 AM   #15
The Wheels Keep Turning
 
kevinlongisland's Avatar
 
Join Date: Jan 2004
Location: Phoenix, Arizona
Posts: 2,831
Default

You can buy this version online if you can't find it locally:

http://www.radioshack.com/product/in...entPage=search

Arctic Silver® Ceramique Thermal Compound

Electrical Insulator:
Céramique does not contain any metal or other electrically conductive materials. It is a pure electrical insulator, neither electrically conductive nor capacitive.
kevinlongisland is offline   Reply With Quote
Old 07-28-2007, 07:26 PM   #16
GOT SCALE ?
 
Stormin2u's Avatar
 
Join Date: May 2007
Location: Taylors Falls just hanging with the MNRCRC crew.
Posts: 7,799
Default

Kevin,

That was a great thread I have been looking for a new more powerful servo and I like the Hitec 5995 but I was concerned about it overheating.

My Futaba Magnum 2PL has epa so I should be able to cut the 180 degree rotation to something closer to 45 or 50.

I'll be ordering one soon TCS of course

Thanks Stormin'
Stormin2u is offline   Reply With Quote
Old 07-28-2007, 07:40 PM   #17
I wanna be Dave
 
Join Date: Oct 2005
Location: Columbia TN
Posts: 6,154
Default

I got a pair of these from Kevin for my super, they are top notch for sure. Just be sure to keep your fingers away from them.........:-(
Kamikaze is offline   Reply With Quote
Old 07-31-2007, 08:06 PM   #18
The Wheels Keep Turning
 
kevinlongisland's Avatar
 
Join Date: Jan 2004
Location: Phoenix, Arizona
Posts: 2,831
Default

Quote:
Originally Posted by Kamikaze View Post
I got a pair of these from Kevin for my super, they are top notch for sure. Just be sure to keep your fingers away from them.........:-(
LOL! When I first got a robot servo I wanted to see much torque it had. So I tried to stop it with my thumb. It almost broke my thumb! Yup, keep fingers away from robot servos!!!!
kevinlongisland is offline   Reply With Quote
Old 08-13-2007, 01:37 PM   #19
RCC Addict
 
Join Date: May 2006
Location: China Grove, NC
Posts: 1,395
Default

hey there

How many servos can be treated with each tube of the Radio shack stuff?

I might as well do all my robot servos at the same time.


Thank you in advance.

Rene
renoirbud is offline   Reply With Quote
Old 08-13-2007, 07:50 PM   #20
The Wheels Keep Turning
 
kevinlongisland's Avatar
 
Join Date: Jan 2004
Location: Phoenix, Arizona
Posts: 2,831
Default

The last time I did one I put the whole tube in there. It filled the entire area inside. I think that will provide the most protection.
kevinlongisland is offline   Reply With Quote
Reply



Thread Tools
Display Modes

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
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -6. The time now is 01:33 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO ©2011, Crawlability, Inc.
Copyright 2004-2014 RCCrawler.com