Heatsinks

[kiyoukan]

been looking into making a heat sink for my lasers, And have found a way to make them, but before i go ordering and machining them out wanted some advice.
i was thinking about making them out of Aluminum 6061-T6 Bare Extruded Square 1.25".
I know copper is better but the price difference is huge.
I can make them for about $0.93 per unit.
That includes everything even shipping.
Each unit would be 1.25" Square.
1. Is this type of aluminum good for heat sinking?
2. Does this price per unit sound reasonable as far as material coasts?
3. Any advice for making heat sinks as far as machining goes? besides a tight fit is the best fit.
4. Any other things i might want to know.

 

[StridAst]

Aluminum has mediocre thermal conductivity. copper will conduct heat away almost twice as fast. I am no expert on lasers here, still a newbie myself, however it seems to me the basic concept is this. the faster you carry away the excess heat, the quicker that heat reaches the air to start dispersing, and the longer time you have before the heatsink around the diode is saturated with heat. once it's nice and warm, you MUST turn the laser off, or risk the diode frying. If a metal conducts it away twice as fast, then it takes considerably longer before the heat buildup is enough to force you to turn your laser off. The performance means much more then the price of the metal you are starting with. Besides, you could always start with copper tube for your heatsink, it doesn't need to be a solid block to machine it out of. If you can change the shape of your starting piece before manufacturing you can minimize waste and therefore lessen cost...

StridAst

 

[ColdStl]

Are you talking about chop sawing a square piece of aluminum and drilling a hole in it? If that's all, then $0.93 is a good price.
Any fins cut into them? Are they gonna be polished? Mounting capability?
For reds and violets, 1.5" works. For greens, you may want to extend the length a bit.
Just make sure the hole is centered all the way through.

 

[Meatball]

Set screws are a must if you are making these for laser modules. If its for a c-mount or something else of the sort, the design limits are boundless.

Thats a nice and low cost for a heatsink!

Perhaps consider selling them? Hint Hint.... lol

-Tyler

 

[kiyoukan]

I have considered copper for the reason no one else seems to sell them. (could be wrong here)
for copper i can make each unit for about $8. material and shipping.
I have yet to put any labor coast into this.
As far as the shape these would be for lab style not hand-held. not to say i could not make them its just i have no idea what the common size would be to make them and it seems people all ready have them, not here to step on any toes.
I was thinking of machining fins into the heat-sink kinda like my cpu cooler. Also give it mounts for a fan. How ever fins that deep would coast more so the standard would be .25 in fins all around.
My cnc machine could produce around 10 a day.
To do deep fins i would need to make a wax mold of what i want set it in stone then centrifuge the metal into it. (if you don't know that is a pain in the @$$, takes a lot of time and i always seemed to get burned.) i could go with out the spinning but then i lose quality.
as far as selling them sure, i have no idea what i would charge. they could be easily custom cut to fit needs so i have a lot to think about after i make mine. if they work well i would love to bring them here to LPF. Still thinking of copper but its such a pain to work with.
As far as set screw go this would be a very tight fit you would need a vice to put it into the heat sink. so i see no reason for a set screw.

 

[Mrcrouse]

The press fit is the same idea I had originally been going with for some MXDL heatsinks I had made, and it seems that most people don't really like the idea too much. Plus there is some variance in Aixiz modules outerdiameters. I would suggest machining the hole as close as you can to the aixiz module so that it is still able to slide through, and then add a 1.5mm set screw. This method seems to be the perfered for people who are interested in buying heatsinks.
Hope this helps you a bit.
-Mike

 

[kiyoukan]

if the fit is not tight there is not much use for the heat sink. there is still heat transfer yes but a lot less. I would try to make it as close as possible and maybe thrown in some sand paper for those who cant get there to fit. i could install a set screw but even if hand pushed into the unit it should be tight enough that it would not warrant the screw. plus as the laser heats up it expands so dose the heat sink but the housing would expand faster making it a tighter fit.

 

[Mrcrouse]

I agree with you 100%. I am just speaking from the experiences I had when I made heatsinks where the modules had to be press-fitted into the heatsink.

 

[f22warzone]

Just wondering but where are you getting the aluminum from? as i am looking for an aluminum plate about 12"x14"x.5" any idea on a price?
but that seem to be a good idea on the heat sinks

 

[kiyoukan]

for a Aluminum Bare Plate 6061 T6 12"x14"x.5" 90$
not cheap to get it that thick from my place to get something that size i would use ebay. eBay Seller: lowcostmetals: Business Industrial items on eBay.com i use this guy alot.

 

[ColdStl]

Just wondering but where are you getting the aluminum from? as i am looking for an aluminum plate about 12"x14"x.5" any idea on a price?
but that seem to be a good idea on the heat sinks

If you kept it at 12"x12"x.5" it would be a lot cheaper, $58.46 plus shipping.
Order Aluminum 6061 Plate in Small Quantities at OnlineMetals.com

 

[mkdive]

I cant believe you cant by locally for cheaper? I have a local metal shop that has just about any kind, shape, size, length, polish, texture, etc... I could ever think of much less want. I'm always surprised how cheap I walk out of there for. Have you tried looking at your local metal supplier?

my .02

 

[kiyoukan]

I have and i had about 3 different ones. I live in MI and wouldn't you know it they all closed their doors. so now i am back to onlinemetals. Looking into new local places but they all are seemingly closing or are unable to afford anything that they don't already have. currently trying to get in the door of grainger industrial supply co. they have a local ware house near me so i might be able to get it from them. they are a few $$ cheaper and i might be able to just do pick up so i don't have the $15-$30 shipping fee.

 

[f22warzone]

Thank you for looking at prices for me : ) looks like I will just go with .250 though, that is a bummer that their all closing their doors good luck on finding some body

 

[kiyoukan]

Thanks. hoping to find a new place but i don't think i want to work with copper right now. as far as selling it will take a while before i get my design finalized. but before you order from onlinemetals check out grainger supply co they ship cheaper and are on average $10 cheaper.