Luxeon Heatsink / Mounting questions. Please help

These are super easy questions and besic I'm sure but I don't know them so it's a big help.

a) Can I mount a 1W Luxeon using superglue?

b) Can I use a bolt as a heat sink?

I've though about this a few times and have a few lights with an aluminium cap that holds down the bulb. I was going to use my tap set to put threads in there and mount the 1W to the head of the bolt and just screw it in.

I figured I could drill a hole in the bolt for the + and midify the bottom to make contact with the batter contact. The bolt would ground to the body for the - contact.

Cheap and easy but does a bolt have enough mass to take care of a 1W led's cooling needs?

Thanks a million,
Adam

Re: Luxeon Heatsink / Mounting questions. Please h

more than likely yes, but I would not recomend superglue.

is it an aluminum bolt?

Trick is a smooth and flush mounting surface, be careful the + does not ground out

Re: Luxeon Heatsink / Mounting questions. Please h

Okay, I was going to look into aluminum, I want to use easy stock stuff and I'm sure I can use something like Brass, Copper or Aluminum without much trouble.

What is best to mount with? Honestly, I can't deal with the acetone smell of many glues so I want something with a low amount of smell.

Re: Luxeon Heatsink / Mounting questions

[ QUOTE ]
SonoranFun said:

a) Can I mount a 1W Luxeon using superglue?

b) Can I use a bolt as a heat sink?


[/ QUOTE ]

a) Yes. Because superglue has poor thermal conductivity, you should make sure both the back of the Luxeon slug and the top of the heatsink are as smooth and flat as you can make them, and you should press down on the Luxeon while the superglue is setting up, to keep the glue layer thin.

b) A steel or stainless steel bolt will not have enough thermal conductivity to work effectively as a heatsink. An aluminum bolt would be fine, but solder will not stick to aluminum (if you wish to solder the negative lead to the bolt). A brass bolt is OK, but a copper one is best by far. Both brass and copper wet easily with solder, but copper is 3 to 4 times better at wicking heat than yellow brass.

Good luck!

Chalo Colina

[ QUOTE ]
Yes. Because superglue has poor thermal conductivity

[/ QUOTE ]

Wouldn't that be bad? I would think you'd want something with a good thermal conductivity to transfer the heat to the bolt?

I'll stay away from steel bolts and see what I can find out there.

Thanks for all the help and superglue and a bolt make for a very easy mod.

Adam

sonoran, i think you mistook challo post. he said because "the superglue has bad thermal prop, you should make sure both the back of the Luxeon slug and the top of the heatsink are as smooth and flat as you can make them, and you should press down on the Luxeon while the superglue is setting up, to keep the glue layer thin. "

Okay I got you, he was saying it from an if you have to use it standpoint make the best of it by doing that.

Is there something else that will work better and doesn't have a ton of oder?

Adam

Arctic alumina /ubbthreads/images/graemlins/smile.gif

I think I have that for CPU's in my computers. It's not for bonding though is it?

Adam

Re: Luxeon Heatsink / Mounting questions. Please h

Artic Alumina EPOXY...As far as HS, it really depends how hard you are going to drive the luxeon, and if your using the star or emitter, steel "cloud be fine" but its not very good. If you have some artic alumina you could mix it with superglue to make it better, but artic alumina epoxy is best.

Re: Luxeon Heatsink / Mounting questions. Please h

Okay I got it figured out. Sorry for so many posts about something so simple but now it's here. I'm going to use a dot of thermal paste in the middle of the Emitter with a few dots of superglue on the sides to hold it all in place.

I'll have at it on the bolts with a grinder then I'll get the top flat and smooth with some sand paper so I'm assured a good contact.

We'll see how it all works out. I'm just playing to see what you can and can't get away with.

Does a 1W Luxeon put out as much or the same power as a 2D normal mag?

Re: Luxeon Heatsink / Mounting questions. Please h

[ QUOTE ]
SonoranFun said:
I'll stay away from steel bolts and see what I can find out there.


[/ QUOTE ]

For copper bolts, check an electrical supply house. Copper washers can also come in very handy!

Chalo Colina

Re: Luxeon Heatsink / Mounting questions. Please h

My guess would be a little more but uses less power, with 2D's I believe you will need something to boost the voltage and current though, so it may appear to be less..You should go with a 3D or 3C light...and a Lux III and a hotlips HS...

But since your just playing you will just have to find out...a 1 watt High Dome red can Direct drive of 2 batteries and still be plenty bright as I have found in a little experiment a few days ago.

Re: Luxeon Heatsink / Mounting questions. Please h

Are there any thermal expansion issues with mounting the aluminum star base onto a copper platform? In other words, would the different expansions of the aluminum and copper stress/crack the glue bond? I'm using loctite with arctic silver added.
Stu

Re: Luxeon Heatsink / Mounting questions. Please h

I think it would be better to use superglue on the edges of the star and use just As3 in the center...I don;t know much about using locktight as glue...

Re: Luxeon Heatsink / Mounting questions. Please h

please refrain from using superglue. it will only make things bad, both aesthetically and the smell. Superglue will form smoke when it dries out and without proper ventilation, the smoke might as well get into your lux's dome. Also, super glue smell bad, but that is just a matter of preference

my advice is to use more thermal epoxy at the base and press the lux tightly (not on the dome please), until you sure it is completely flat with the heatsink. then there will be some small epoxy to get out from the bottom and that will help some thermal transfer and some bond also.

Re: Luxeon Heatsink / Mounting questions. Please h

[ QUOTE ]
shiftd said:
please refrain from using superglue. it will only make things bad, both aesthetically and the smell. Superglue will form smoke when it dries out and without proper ventilation, the smoke might as well get into your lux's dome. Also, super glue smell bad, but that is just a matter of preference

my advice is to use more thermal epoxy at the base and press the lux tightly (not on the dome please), until you sure it is completely flat with the heatsink. then there will be some small epoxy to get out from the bottom and that will help some thermal transfer and some bond also.

[/ QUOTE ]

I do not htink he is using thermal epoxy, he is using plain AS, not AS epoxy...in this case it would be better to use an edhesive on the outside and AS in the center...Or I have heard of some people mixing AS in with superglue, But I don't know what the results are...

For me I just wait to go buy some AA epoxy or As epoxy...

Re: Luxeon Heatsink / Mounting questions. Please h

yep
better to use AA or AS epoxy

well, i did not read his post completely /ubbthreads/images/graemlins/blush.gif . but still though, using superglue always lead to disaster to me. /ubbthreads/images/graemlins/banghead.gif