Heat sink options: materials and sourcing ideas?

[xevious]

Where have most people here managed to get their heat sinks for flashlight projects?

I realize that with the many different diameters of flashlight heads that there isn't any "standardized" heat sink size. In looking over many threads about DIY projects, it often looks like people have to custom make their heat sinks or be lucky enough to have a suitable one lying around. Yet without a lathe (for many of us), that puts a major obstacle on creating one at home.

So, my guess is the viable alternatives would be:

• Found object -- part sourced from another object, inexpensively found
• Junk yard -- rummage around until finding something close enough that can be modified
• Plumbing/building supply -- check on scrap materials that might be purchased on the cheap
• Machine shop -- pay someone to make one; I suspect the cost might be prohibitive, relative to other part costs

What might be some other alternatives?

As for materials, it seems like copper is one of the best conductors of heat, so that is an obvious choice. But is it really necessary? I imagine for a given lumens threshold, it may be over kill and that a "lesser" material may be fine enough for the job. What would be some other candidates? Aluminum, brass, lead, etc? I wonder if there might be some kind of metallic based ceramic possible, one that you could roll up into the desired shape, bake in an oven, then sand/finish as needed.

Well, the good thing about copper is that it's a soft metal (especially when compared to aluminum or brass), so it can be forced into various shapes at the right temperature without enormous effort or machinery (except a lathe for achieving a round shape). You can easily buy copper piping from various places (including Home Depot), but I have yet to see solid rod stock offered for sale. Is there a certain kind of store/business where you can buy segments of copper rod stock?

 

[spencer]

Around here aluminum is the most common metal used. To have mine made for a custom Maglite, I made some drawings up and then had my uncle turn them up on the lathe at the farm in exchange for a couple hours of labour. Without having that option, my plan B was to try to source somebody on this forum to make one (guys offer from time to time) and plan C was to have one turned at a local shop. I didn't have it priced out but I assumed it would have been prohibitively expensive (although usually you can find someone who is willing to work for cash on a one-off to help bring the costs down).

 

[seven11]

Probably the easiest place to get heatsink materials is from onlinemetals.com

If you need some aluminum, I have a rod that I would send to you for free if you would cover shipping. I'm located in Ohio. It's about a foot long and around 2 inches in diameter. I bought it at an auction to make some heatsinks and then never got around to using it.

I hope you didn't get hit by Superstorm Sandy, I was just in Newark a few weeks ago helping some homeowners get their insurance payments. Lots of people in difficult situations there.

 

[xevious]

Good to hear that aluminum is widely used and with success. Seven, thanks for mentioning onlinemetals.com, as they have a great selection and you can even order custom cut pieces. The trick is just finding the right diameter rod stock. Thanks very much for the offer on the 2" aluminum rod! I'll have to double-check on my planned projects and see if it'll work, and PM you.

 

[skyfire]

ive seen aluminum rods sold at home depot

 

[think2x]

Speedymetals dot com is what Oldlumens uses and what I will most likely use soon.

 

[Old-Lumens]

Custom made heat sinks are the best way to go, because whoever makes them for you will make the heat sink a tight fit and they can even make it to special needs, like a pedestal, etc.
Making heat sinks out of comkon parts found in the hardware can be aggrivating. Usually nothing "fits quite right" and compromising is the name of the game.
It all boils down to cost doesn't it? For those with the funds, having custon stuff made is the way to go. For those of us with limited funds, then "making do" or not doing at all, is usually the way.
There are online shops like speedymetals that will cut rod stock to length. They say minus 0 to plus 1/8", but if you ask for exact cut, they will do it for you. The problem is that most of the time, the rod is not the right diameter and some kind of spacer is needed, like shim stock or sheet stock.
If you have any contacts with local shops, they might be a good source for custom made heat sinks. Otherwise, someone here can always be found, than can make them.

 

[BeastFlashlight]

Why can't my heat sinks be made out of this http://computer.howstuffworks.com/heat-sink2.htm What's the hold up this article is 2 and a half years old

 

[xevious]

The other thing is that if you're not planning on swapping out the emitter very often, you can go with a slightly loose fit and pad it with copper sheeting until you get the desired diameter. Fine for DIY projects, but not for resale.

 

[MikeAusC]

I've found computer shops that specialise in modding, or fleamarkets an excellent source of cheap highpower heatsinks.

Once the Processor for an expensive add-on heatsink is no longer available, they'll sell it at a big discount.

 

[Hmmm]

I've been looking for some place to buy copper stock for a heatsink, both round and flat bar, but I can't find anywhere local. So far ebay seems to be cheaper than online metals.

 

[DIWdiver]

Aluminum stocked by home centers and hardware stores is usually very soft (nearly pure aluminum) and is very hard to machine, i.e. drill/tap. It gums up files and grinders. In general, I would recommend aluminum, alloy 6061-Txxx, where xxx is a one or three digit number starting with 3 or higher; T3, T6, and T651 are the most common, but others exist.

McMaster-Carr stocks many alloys, shapes, and sizes of various metals including copper and aluminum. They aren't cheap though.

Yarde Metals sells odds-and-ends in their 'drop zone'. Prices are almost stupid cheap, but the minimum order is $75.

For a small, custom, 1-off piece I would consider emachineshop.com. I haven't been there in a while, so I don't remember what you have to submit for a design, but you can get a quote right online, instantly.