Machsupport Forum

Tangent Corner => Tangent Corner => Topic started by: budman68 on July 14, 2009, 04:56:46 PM

Title: Aluminum Heat Sink Adhesive?
Post by: budman68 on July 14, 2009, 04:56:46 PM
Well I ran my first real "production" job on my little Taig Lathe the other day and the motor will definitely need some cooling to help keep her cool.

Made up some aluminum heatsinks but does anyone know if this thermal epoxy will be strong enough to handle the vibration of a motor? The aluminum heatsinks will be epoxied to an aluminum sleeve that I have over the motor. I believe I'm going to add an 80mm fan as well.

http://www.directron.com/silverad.html

Thanks for any help-
Dave

Title: Re: Aluminum Heat Sink Adhesive?
Post by: RICH on July 14, 2009, 06:37:55 PM
DAVE,
There are a number of transfer cements that can be purchased. You want to get something with a high heat transfer coefficient. Paint on a motor affects the heat transfer rate. Actually you should do some calc's to see what
can be accomplished.
RICH
Title: Re: Aluminum Heat Sink Adhesive?
Post by: budman68 on July 14, 2009, 07:16:45 PM
Hi Rich,

Thanks for replying but what exacty do you mean by "Paint on a motor affects the heat transfer rate."?

Are you saying to paint the motor to help lower the temp? Or just the opposite? FYI : The motor is not painted, I have an aluminum sleeve covering the housing. A pic may help-

Thanks,
Dave

(http://www.machsupport.com/forum/index.php?action=dlattach;topic=8428.0;attach=6755;image)


Title: Re: Aluminum Heat Sink Adhesive?
Post by: RICH on July 14, 2009, 09:25:10 PM
Dave,
If the motor is not painted then leave it that way as the paint blocks the transfer of heat ( not a whole bunch but it has an effect. Your Al cover is not helping and is actualy hindering the heat dissipation away from the motor casing. You actually insulated the motor somewhat since air ( has a poor heat transfer coefficient ).

Rough rule, say the motor is 80% efficient, so 20% of the wattage is heat generation. The heat travels through the case, the paint, the heat transfer cement and finaly thru the jacket. The heat transfer cement allows for a higher transfer of heat as compared to the air. So the resistance to heat travel is made up of  by each of the individual
heat trasnfer coefficients.

Maybe just leave a gap say, 1/2" around the motor to the Al shield and blow some air through the gap, sort of like
a hair dryer. Or have a little fan blowing across it.

RICH
Title: Re: Aluminum Heat Sink Adhesive?
Post by: budman68 on July 15, 2009, 09:38:46 AM
Thanks Rich, yes, the motor just has the original plating on it and I actually thought by having the aluminum sleeve, it would actually help things in this case (pun intended). I'm going to do a little experimenting and see if I can get some temp comparisons to see if I'm actually helping with my experimentation or just making things worse  :D

Thanks for the lesson as always, Rich-
Dave 
Title: Re: Aluminum Heat Sink Adhesive?
Post by: budman68 on July 28, 2009, 05:30:29 PM
So I purchased the Arctic silver epoxy and mounted my little heat sinks and a 120mm fan to blow over them. I ran the motor for an hour and it's cool so it's working perfectly. Not pretty, but VERY functional...... lol!

Now I just have to give it a workout with some actual cutting  8)

Dave

(http://nq2rww.bay.livefilestore.com/y1pa-S9jTc1li5VEpN4ySX9pZyuLFATWvlMyZPRvlSJ72nrGHCEajiD13WIVStqzQ93tlVO0dYGlSotnamLt9eUDg/MotorFanfin.jpg)

(http://nq2rww.bay.livefilestore.com/y1pcNddfe7SQvIBaAJPnSo-B-D4WqoV8VlRdCx7l6Pc96GwQv4i8oqJt4PFMBmAHqstM0tM2wemyHO8iDWqX05nGw/MotorFan.JPG)
Title: Re: Aluminum Heat Sink Adhesive?
Post by: Chaoticone on July 28, 2009, 10:23:35 PM
Dave, that really doesn't look too bad. Main thing is it works.

Rich, you sure do give a lot of helpful informatiion.


Brett
Title: Re: Aluminum Heat Sink Adhesive?
Post by: RICH on July 28, 2009, 10:47:13 PM
Hey Brett,
Tell that to my former employer!   ;D   ;)
( they appreciated me , but when there is nothing .....you know how it goes )

Like i tell the wife...... I know everthing - just can't seem to recall it anymore  :D  :D  :D

RICH
Title: Re: Aluminum Heat Sink Adhesive?
Post by: Chaoticone on July 28, 2009, 11:26:35 PM
LOL Rich, that is so true. Lots of people get upset when the work is low, but if there is nothing to do, there is nothing to do.

I often say "The locker is full. Can't put anything else in unless I throw away something else." LOL

Brett

Title: Re: Aluminum Heat Sink Adhesive?
Post by: budman68 on July 29, 2009, 11:13:06 AM
Main thing is it works.

Indeed-  ;D

Dave
Title: Re: Aluminum Heat Sink Adhesive?
Post by: Tweakie.CNC on July 30, 2009, 02:54:44 AM
Hi Fellas,

Every time I throw something away (to make room) it's not long before I need it and then regret throwing it.
Perhaps a 'recycle bin' (on full pay) that gives us a second chance should be mandatory for all employers.

Tweakie.