What happened to aluminum sandwiching?

zeroneleven · Post by **zeroneleven** » Thu Feb 14, 2008 2:33 am

I'm in the process of building a DAW and I'm at the stage where I need to decide how I'm going to minimize both of my HDD's noise & vibration. Suspension seems to be a popular choice here, but like most methods I've read, it doesn't take into account the effect it has on the temperature of the drive.

My Centurion 5 case doesn't make drive silencing easy. The 3.5" cage extends to the floor making it impossible to suspend a drive in the path of the intake fan. After reading Mike Chin's original article on aluminum sandwiching, I decided that it would be a good solution for dissipating heat. The aluminum not only acts as an effective heatsink but, with the foam lining, also dampens the vibrational noise. I figured that if I also rested the sandwiched drives on acoustical wedge foam, this would all but eliminate audible noise while keeping the drives cool and allowing air to flow underneath as well.

Unfortunately, I read that MikeC no longer recommends aluminum sandwiching and there seems to be no discussion of it here in the past few years. So my question is, why is this method no longer accepted? Other than the fact that it would cost ~$80 for the 3/8" aluminum at McMaster, it seems a good way to quiet a drive and, just as importantly, prevent overheating. My other question is, if sandwiching isn't a good idea, what else can I do to keep my drive temps down? In my case, if I suspend them in the upper 5.25" cage, there's no airflow. If I just rest them on foam, they'll fry pretty quickly. As I said, it's not always easy (or desirable) just to throw a fan in front of a hot drive.

Any input would be appreciated.

BTW, my two drives are a WD 7500AAKS & WD 3200AAKS.

Bluefront · Post by **Bluefront** » Thu Feb 14, 2008 3:38 am

As you figured, conventional suspension techniques make drive temperatures go up. There are other methods that can be employed.

Check out the suspension in this setup. The two drives are sitting on soft foam, inside a copper cage, with airflow from underneath that keeps both drives only a few degrees over ambient. Guaranteed....you'll never hear the drives again, and they'll be plenty cool enough for anyone. (glances over at his drive temps...26/27C. Cool enough?) The room is 23C right now, and both drives have been running for 2 hours.....haven't heard either yet.

zeroneleven · Post by **zeroneleven** » Thu Feb 14, 2008 12:49 pm

Nice job with that setup! I like how the orientation of the fans makes use of heat rising. Unfortunately I'm too much of a noob to pull this off. Plus it wouldn't work with my computer desk setup. The copper HD cage looks very interesting though. Can you buy one of those, or did you make it yourself? How did you remove the 3.5" cage from your case? I would like to be able to do this and suspend or soft-mount a similar HD cage in front of my intake fan. This would satisfy that the HD's are a) in the path of a fan with open airflow above and below each drive, b) secured to an effective heatsink, and c) decoupled from the case.

Bluefront · Post by **Bluefront** » Thu Feb 14, 2008 2:05 pm

The copper cage is DIY....and difficult. It's all soldered together. I had to rivet it together first, because the heat from the small torch was trying to warp the panels......plus as I soldered one joint, the solder on the previous joint would melt. It was a lot of fun.....

That case is probably similar to yours? The center 3.5" cage is held on with some rivets....you simply remove the front bezel, and drill them out. That's it. There is enough room then to suspend the OEM HD cage in that spot.

zeroneleven · Post by **zeroneleven** » Thu Feb 14, 2008 3:28 pm

What is the thickness of the copper you used? Could I use aluminum instead? I realize that copper has slightly better thermal conductivity, but it's also about 5x the cost of aluminum.

Bluefront · Post by **Bluefront** » Thu Feb 14, 2008 3:57 pm

It's .025" copper. There's <$15 of copper in there. The problem with aluminum in such a setup.....it cannot be soldered. But I guess you could just rivet the panels, but the heat transfer will not be nearly so good. For the cost, I'd use copper.

There are about 3 sheets 4"x10"....from Ace hardware or other places, like hobby stores.

zeroneleven · Post by **zeroneleven** » Thu Feb 14, 2008 7:22 pm

I see from your profile that you're a machinist so you would obviously know more on this subject than I do.. but isn't soldering and welding of aluminum pretty common? If so, I think I'd rather get thicker aluminum for my drive cage. Although copper has about 60% better thermal conductivity than aluminum, it's 3 times the price/lb. For the same price as those .025" copper sheets, you can get (3) .125" x 6" x 8" aluminum sheets. I would think the thicker aluminum should conduct more heat. In your case it really doesn't matter though, since your system has such good airflow and ventilation to begin with.

alleycat · Post by **alleycat** » Fri Feb 15, 2008 1:30 am

Here's an enclosure that's extremely effective and very easy to make. Mine has had over 3 years of almost constant use so far, and a number of other forum members have successfully built this enclosure also.

Bluefront · Post by **Bluefront** » Fri Feb 15, 2008 1:58 am

It's the surface area of the metal that conducts the heat away into the air. A thicker metal would only take longer to heat up, after that it's the total surface area of the metal, and the airflow that matter.

Solder aluminum.....humm. Not with anything I own. You could use epoxy on the edges of aluminum sheets, but not normal solder. I used a small torch to solder the joints, and a roll of silver-solder.

Brians256 · Post by **Brians256** » Fri Feb 15, 2008 2:42 pm

I wouldn't feel bad. Most people don't have a TIG welder.

Edwood · Post by **Edwood** » Fri Feb 15, 2008 5:56 pm

Bluefront wrote:The copper cage is DIY....and difficult. It's all soldered together. I had to rivet it together first, because the heat from the small torch was trying to warp the panels......plus as I soldered one joint, the solder on the previous joint would melt. It was a lot of fun.....

That case is probably similar to yours? The center 3.5" cage is held on with some rivets....you simply remove the front bezel, and drill them out. That's it. There is enough room then to suspend the OEM HD cage in that spot.

Yeah, soldering copper sheet is a pain.

What worked best for me was to clamp everything, and solder everything at once, of course that just makes the warping problem worse. You can always hammer it out later.

-Ed

zeroneleven · Post by **zeroneleven** » Fri Feb 15, 2008 11:10 pm

Bluefront, you're right, once the HDD cage reaches equilibrium, the surface area is all that matters.

As for welding/soldering copper and aluminum.. it's a moot point for me since I don't have the necessary tools or skills to make a proper DIY drive bay. I also doubt it would help much with seek noise and high pitched whine.

That's why the idea of sandwiching a drive between two thick plates of aluminum with foam around the sides appealed to me. It seems like an easy, effective solution. You get good vibrational damping, decent noise reduction, and excellent passive cooling. I would still like to know why no one here recommends it anymore.

As for alleycat's enclosure method, I read through your thread and it does sound impressive. I have no doubt it would completely shut my drives up. Plus it'd be easy enough for me to do, provided I find the right enclosure and gel packs. I'm just not sure about the cooling effect of the gel packs. Because they're meant to store and not transfer heat, they could potentially keep a hot drive from cooling down. In fact, why not just eliminate the gel packs altogether and have the aluminum in direct contact with the HDD (back to Al sandwiching).

Having said that, I'm strongly consdering the enclosure + gelpack option. I even found this box on ebay. The dimensions seem good, but it might be tricky to mod for the cables. Any advice?

jaganath · Post by **jaganath** » Sat Feb 16, 2008 2:24 am

That's why the idea of sandwiching a drive between two thick plates of aluminum with foam around the sides appealed to me. It seems like an easy, effective solution. You get good vibrational damping, decent noise reduction, and excellent passive cooling. I would still like to know why no one here recommends it anymore.

it's a lot easier to just buy a laptop HDD and forget about all that stuff. if you need huge storage, just have it external, far enough away so that the noise doesn't matter.

Bluefront · Post by **Bluefront** » Sat Feb 16, 2008 2:25 am

I played around with gel-pacs for a while. Think about what they are used for.....they store heat, and they transfer heat to, or remove heat from any object they are touching. So in theory they should work at removing heat from a HD, and transfer that heat to whatever else they are touching.

And they dampen HD vibration effectively, as well as toning down HD noise.

Cons....They make for a large package, and difficult to use more that one drive in a standard-sized case.

They can split open, dumping/leaking their contents everywhere, with unknown results.

And they can cause moisture build-up between the drive and the Gel-pac. That's why I stopped messing with them....not worth the risk.

alleycat · Post by **alleycat** » Sat Feb 16, 2008 6:28 am

zeroneleven wrote:I'm just not sure about the cooling effect of the gel packs. Because they're meant to store and not transfer heat, they could potentially keep a hot drive from cooling down.
...
I even found this box on ebay. The dimensions seem good, but it might be tricky to mod for the cables. Any advice?

My drive temperatures have been consistent for three years, and my case has very low airflow.
That box looks like it is of much lighter construction than the one I used. It might work though. Are you willing to experiment?

jaganath wrote:it's a lot easier to just buy a laptop HDD and forget about all that stuff

That's a valid point. It's worth considering what you really need.

Bluefront wrote:They make for a large package, and difficult to use more that one drive in a standard-sized case.

They can split open, dumping/leaking their contents everywhere, with unknown results.

And they can cause moisture build-up between the drive and the Gel-pac.

The first point is certainly true, however I have seen other forum members use two of them in one case, but mounting options are limited. It is worth keeping in mind that the enclosure+drive is quite heavy also.
The second point is feasible, but I've never had one break, even after harsh treatment. I suppose it depends on the manufacturer.
The last point doesn't make sense, and has been discussed in other threads.

Note also that there are a number of commercially available enclosure kits. I don't think they perform quite as well as my design, but some of them may work well enough. One of the forum members, nici, did a roundup of the various enclosures.

CyberDog · Post by **CyberDog** » Sun Feb 17, 2008 3:20 am

Hello. I have seen one guy sandwiching hdd:s between two aluminum plates and then between two sand sacks. Said that it was inaudible and cool. The drive was a raptor.

But what comes about commercial drive enclosures. I have a Nexus enclosure and it's not silent. I needed to suspend it. It cut downs the spinning sound quite well but not the seek. I also have Scythes enclosure, but I haven't tested it yet. It feels much better tho. If it's not silent enough I'll but it to alleycat enclosure