Hi guys does anyone know where i can get a decent copper heat sink to fit into a mag D and let me attach a SST 90 ?
I really think there's no huge advantage over aluminum, I'd use one of the available aluminum heat sinks.
There is a guy on CPF that sells them I think.
I've never known anyone that actually sells pure copper heat sinks, due to the cost. I have seen some make their own, but it was usually because they happened to already have some copper rod stock. One foot of 1-3/8" copper rod stock is about $100 USD, so I think it's a little out of the average budget modders reach.
Aluminum will work fine unless you are looking for running it at the full 9Amps till the batteries go dead. There is a good aluminum one for it, on CPF, but it's still about $50 for the Aluminum heatsink, machined specifically for the SST-90. I'm at work, so I can't find the link right now, if you decide you want it, I can find it later.
Here the thread is. I had thought they were copper but I was mistaken, sorry.
http://www.candlepowerforums.com/vb/showthread.php?310770-********-H22A-Heatsinks-********
Cheers guys, i've used the Der Wichtel heatsink a few times now and i'm very impressed with the quality..
Would lead make a good heatsink?
This is not an offer to build as I barely get enough machine time for my own projects. Copper does come at a high price and if possible have used 1” copper round pressed into aluminum for my PT54 high ampere applications. For my 25A+ driven PT120 green Mag 4D aspheric build solid copper was the only option starting with a 1.5” dia x 3” long. Even with this massive hunk of copper it still gets hot in about 90 seconds.
Sorry for the thread hijack, but this got my inner cheapskate thinking... has anyone tried cutting round bits of sheet copper, stacking them, then cooking them into one solid mass with solder? Or do I remember reading somewhere that solder is really cr!p for heat transfer? I've got some 3mm copper kicking around, and would need 3 or 4 layers to make a mag C insert.
(Somehow, and I know this isn't rational, it hurts to pay 25 bucks for a hunk of milled aluminum.)
I've done something similar except with copper endcaps and you stack them inside each other and fill the rest with solder.
I made a large copper heatsink for bigChelis for a 3D MagLite about two years ago. I still have enough copper to make one more that I was keeping for myself. Here's the thread outlining what was done:
Copper offers an initial performance advantage over aluminum until the heatsink and host becomes heat saturated, at which point they perform the same. The thing is that it takes a bit longer for everything to become heat saturated with copper compared to aluminum.
Thanks for the link, PCC. Among the zillions of mag mods, I'd missed that one.
I use scrap copper and solder all the time. Lead does not conduct heat well at all and tin is not much better, so solder is not good for heat transfer. Silver solder on the other hand is good at heat transfer. I do not think a layer as thin as is needed to solder two pieces together is a problem. At least I’ve never seen it as a problem.
bigChelis was the guy who recommend Tenergy nimh D cell to me for the high amp output for my PT builds. Real nice guy and helpful too!
Cheers guys the reason i'm after a copper heatsink is purely because i want to drive the sst 90 at at least 12amps anything lower and i think there's no point bothering with the mod. :)
Just need to find one in the UK or europe as i imagine shipping would be very high from anywhere further afield..
Just a bit more info about copper. For the best performance you need to go with C101 copper, which is 99.99% pure. I use C110 copper, which is rated at 99.9% pure. That 0.09% purity difference equates to almost double the cost and only a 2-3% improvement in performance. Hardly worth it, IMHO. The thing, though, is that copper with less purity drops in performance quickly from there. That's why I cringe when I see folks building high power setups using hardware store copper fittings of unknown quality. You really don't know what you are getting and you don't know how it's going to perform as a result. You will probably get only slightly better performance than aluminum going this route.
Oh, yeah, bigChelis had a monster 4D Mag made using three top bin SST-90s wired in parallel, direct soldered to copper, and the stock switch wired to a FET to avoid melting the stock switch. That thing was insane. Estimated at 6000 lumens, that light would get scalding hot in less than two minutes. Every light in my collection seemed like a Mag Solitaire after that!
Thanks for the link OL. Surprised me to see it was 99.9% pure.
Yes, that was very informative. From reading that I see that copper pipe has to be made to the same purity standards as C110 copper, which is encouraging. Looking further, though, it appears that the copper fittings are essentially brass. Am I reading that wrong?