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Dear Jesus please resize your image so it's smaller.

Trevor

If you had two heatsinks that were identical in size and shape but one was aluminum and the other was copper, the copper would perform better because copper transfers heat better than aluminum. Two of the most important design aspects of a heatsinks are size and surface area. The rate at which heat is transferred to the surrounding ambient air is dependent on surface area. Greater surface area= more heat transfer to surrounding air. Most computers have finned heatsinks because they work in conjunction with fans that flow air across the fins to aid with heat transfer. Now if this heatsink is enclosed inside a cavity(no airflow) then surface area doesn't do much good and a soild heatsink would be better.

You may want to try "Google" and do some research on heatsinks. There is a lot of useful information already on the web about heatsinks.

Hard to tell which one would work better by those pictures. Some heatsinks come spec sheets that tell you exactly how much heat they can dissipate but you would need part numbers to find that info, if it exists.

Copper vs Alum debate is getting old. They are two different metals and have different properties. Copper draws the heat away from the source better but doesnt dissipate well. Aluminum dissipates heat well but doesnt draw it away from the source.

IMO it'd be better to get a chunk of either metal and just have a bunch of shallow fins cut out like this:
https://www.fasttech.com/products/0/10001927/1173704-909030mm-aluminum-heatsink

I don't know the answer for the heat sinks, I have seen at least a couple of people here use an aluminum one like you have on the left, but how well they work I couldn't say. They aren't made for an Aixiz module so you just have to test them.

As for the the acrylic lens you are safe up to 300mw, beyond that you are probably pushing your luck.

Gabedini said:

both of these are from computers, as can be seen in the picture the one on the right is larger, however has thinner 'slices' than the other one. However it appears to be copper with an aluminum base and the one on the left is all aluminum but due to the thicker 'slices' would have more contact with the laser module.
so which one is better in your opinion?

also, would a solid piece of aluminum or copper work better than these with the slices in them?

also again, what's the highest power you can use the acrylic aixiz lenses for? I accidentally melted the back of one when I was using a dvd burner diode with a driver set at about 300mA

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I would expect the copper heat sink to work better.

Your 300ma @ ~3 VDC is 900 mw.

I would suggest a max of 600 mw (200ma)

LarryDFW

What everyone seems to forget is that even the M140 diodes pushed to their limits are only gonna output <10W of heat, at absolute worst. Those heatsinks could probably handle 100W no problems, so which will work better is irrelevant, they both will work just fine. Just choose one that fits your space requirements better.

Oh give me a break you guys. It's a measly half watt of heat. Even a 10-ton block of copper is not going to be any "better" than the aluminum one pictured. Google diminishing return.

Livinloud said:

Copper vs Alum debate is getting old. They are two different metals and have different properties. Copper draws the heat away from the source better but doesnt dissipate well. Aluminum dissipates heat well but doesnt draw it away from the source.

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Explain the highlighted parts please.

Disperse or scatter the heat.........aluminum doesnt hold on to heat long but copper will hold the heat for longer while drawing it away from the source. The aluminum will cool off faster than the copper heat sink in other words.

This is one reason why copper is used in heating systems since it allows heat to pass through it quickly and it holds the heat longer than other metals (along with not allowing bacteria to grow and a few other things).

Livinloud said:

Disperse or scatter the heat.........aluminum doesnt hold on to heat long but copper will hold the heat for longer

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What are you basing this off of?

the 100 other copper vs aluminum heat sink threads on this site, personal testing and various other sites when doing a simple google search. take an ir thermometer and put two identical lasers side by side. one copper and one aluminum heat sink. run them for 60 seconds and measure the temperatures of the heat sink. the aluminum one will cool off WAY quicker than the copper one.

cant argue with science or test results......ir thermometers are only like $10-20 at harbor freight, go try it and you will see. forgot my thermometer in my parents garage in MA so will need to go pick one up somewhere to post my own results. closest harbor freight to me is 30 miles so need to see if there is a closer source for a decent ir thermometer.

EDIT: Searching for various quotes from threads here and posting below-

RA_pierce said:

Cu will absorb more heat because it has a higher capacity for heat. However, Cu cannot transfer this heat away into the air as effectively as Al. This means that the Cu heatsink will absorb a lot more heat but will hold on to it longer than an Al heatsink would.

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Copper heat sinks are only $5 more expensive for a C6 host than Aluminum, yet you dont see many builds for sale with copper heat sinks. why would you say that is? it isnt based on price, can tell you that much since its only $5!

You do see copper heat sinks in large 9mm builds since it draws the heat away from the source and can hold more heat than aluminum. Aluminum would cool down quicker allowing for quicker recovery time in duty cycles but most people want that long duty cycle so copper is the best choice for a large 9mm build.

Livinloud, I'm pretty sure you're wrong. To my knowledge, the mechanisms of heat loss in our lasers come from thermal radiation and conduction with the air. Both of which happen at the outside edge of the host, and if the heat sink is the outer edge, then either metal can be coated the same color so emissivity is the same. In this case all we really care about is heat capacity and thermal conductivity.

I'm baffled that you think there is some mysterious property to aluminum that makes it lose heat somehow faster than copper.

Its not a mysterious property that makes aluminum lose heat fast, its the fact that copper HOLDS heat longer. Obviously we are not going to come to an agreement, you think one thing and I know another thing from my own testing. If you want to see what I found then go buy a IR thermometer and run the tests yourself. Ill be buying one to use in FL and will post my results as soon as I buy one. Id be interested to see what you find in your testing and you might be surprised to what your results are.

You are right that heat is transferred to the host but Al also transfers heat better than Cu so that would just go towards what Im saying.

I ran my original tests with the heat sinks outside the host so in my new tests ill try it out both ways

We can argue this forever or we can let scientific testing determine who is correct.

Relevant: http://laserpointerforums.com/f44/little-lesson-heatsinks-84449-2.html#post1222372

Trevor

Aluminum can be anodized. Copper tarnishes.