Advice on custom CPU heatsink

[Asherz]

Hey guys,

The other day I found two old computers (not really that old) that I took too bits and found some pretty decent hard drives and DVD writers in etc... So I extracted two red diodes and two IR diodes in there heatsinks which I will be selling if anyone is interested. I also came across a pretty decent CPU heatsink and was wandering if anyone could come up with a way or tell me if it is possible to turn it into a heatsink for a aixiz laser module. I have some pictures of it which I have posted below so if you check them out tell me about any idea's/possiblities. I also have 4 nice little fans which I can use, one of them fits specifically onto the heatsink. Another heatsink I salvadged which is coverd in dust but does on the bottom have a 5X4cm copper block about 8mm in depth if thats of any use.

Thanks in advance,

Ash

PICTURES:

http://img208.imageshack.us/img208/5259/img5857.jpg
http://img144.imageshack.us/img144/4004/img5858.jpg
http://img148.imageshack.us/img148/1116/img5859.jpg
http://img300.imageshack.us/img300/2885/img5860.jpg
http://img406.imageshack.us/img406/9954/img5861.jpg
http://img509.imageshack.us/img509/7454/img5862.jpg


Please note the images are huge so I left them as direct links for you too view.

 

[pseudolobster]

If you could manage to drill a 12mm hole in that it'd make a fantastic heatsink for a laser, if a bit excessive... You'd then also need to figure out some way of mounting it to a flashlight or whatever kind of host you'll be using, so for that it'd be a bit inconvenient.

 

[Asherz]

Thanks, If I drill the hole 12mm, which is exactly the same diamater as the aixiz module... will it stay in place tightly? or might shake a round a little.. might have to figure something out for that..

As for the host I'm not going to be taking out anywhere so the fat heatsink will be the host ^^ I have a little black box to hold a 9V battery with a switch and wires which will be solderd onto the wires coming out of the axiz module.. may get a project box but probally won't bother.. will just end being mounted onto a piece of wood with a whole drilled out for the laser

 

[pseudolobster]

Well, aixiz modules vary a bit in size... If you want it to press fit you'll want to drill an 11.5mm hole then sand it until the module can be forced in place... Otherwise normally people will drill a hole in the side, thread it, and put a "set screw" in place to hold the module... This probably won't be possible through the fins of the heatsink.

 

[Asherz]

alright thanks, apreciated.

 

[Illuminum3415]

hmm....looks like an ordinary P4 heatsink...

I agree with the "drill a smaller hole then sand" idea
what I would do [doesn't mean you have to] is to do whats above, then fill both sides with arctic alumina thermal epoxy, mix a small dab then coat it thinly on the diode with a razor blade, then insert it into the hole, then put a dab or a generous ring of it on the edges oughta do it

heres a very very rough concept drawing

 

[Asherz]

cheers, that helped I will have to see what I can rustle together, I will probally go with the thermal paste, but I can't see how easy sanding the inside of a copper 11.5mm hole will be

 

[Benm]

Not very easy at all - copper isnt the hardest metal, but chances are it is in fact an alloy that is harder than pure copper.

One other idea is that it could be possible to make a hole that is slightly larger than the module, and then solder the (front part of the) aixis right in there. I suppose it would be possible to press-fit the diode after that, and i know for a fact that the axisz modules are made of a solderable metal.

Given the size of the heatsink you'd need a blowtorch to get it hot enough to solder - but it'd probably make the best non-TEC cooler anyone has ever built for a 5.6mm laser

 

[FireMyLaser]

In the ghetto.

 

[Asherz]

lol cool work firemylaser, and cheers for the tips ben,

I wander if its possible to cut the copper so that it has a screw type indents inside, from there I could either make my own module or try and shape the aixiz module so that the entire thing can be twisted/wound into the copper... kind of like a bolt over a screw... Don't know how easy that will be though lol.

 

[Benm]

Hehe.. i reckon that will not be easy.

You can tap tread in the hole in the heatsink, but that will properly require a lot of force to do at 12mm or so diameter... still, with a sharp thread cutter and some leverage it sounds doable.

Tapping thread on the outside of the aixisz will be more problematic: i doubt its walls are even thick enough to cut thread into, and even if it were, holding it in place sounds like a challenge!