Thread: "Soft" hard drive mounting....

This is only one page for me

I've had the -same- WD 60GB hd in my carputer for 3 years now and never had a problem. It's always been mounted 90degrees from the road, or IOW on it's side. Now I've got a WD 80GB drive mounted the same way and it's working fine. The only shock-proofing I've ever done, besides getting new shocks for the car , was mount the board that holds the mobo, hd, and Opus on 1" foam padding. The carputer's box is, however, bolted to the car's body.

Nevermore will I go crazy like I did in the beginning trying to think of ways to shock-proof my drives. But, if someone wants to find a way that makes them feel comfortable thinking thier hd's are "shock-proofed", then go ahead and knock yourself out. Whatever makes you sleep better.

...sorry to dig up an old thread, but I want to know why people think it is better to mount the hard-drive so the platters are spinning parallel to the wheels. Does anyone have any proof?

Also, if it is true, then does it matter if they are spinning the same way or opposite?

Also, I would assume that the best location would be at the cars center of gravity (low in the center-consol)? Is that correct, or would the center of the rear axle be better (front of trunk / under back seat)?

While on the surface, it would appear that mounting it at 90' to the road surface would be a good idea, I can tell you right now that it's not.

A large bump in the road will send shocks through the car, a drive mounted at 90 degrees will do better, because the shock will travel vertically across the plate, as opposed to twisting it.


However, the same drive exposed to high-g turns will be subject to precession due to the realignment of the direction of rotation. This will put far more torque on the platters and motor than any bump that doesn't take your transmission off. A drive mounted with the axis of rotation perpendicular to the road (i.e. the drive mounted horizontally) will be totally unaffected by cornering in an ideal world, and in the real world, only slightly (the car tilts somewhat as it corners)

locating the hard drive toward the front of the car - as opposed in the trunk - would probably result in less shock to the drive.. remember when you were a kid, and everyone wanted to sit in the back of the bus because it was always really bouncy back there?

as far as mounting the drive horizontally or vertically, i think if it was mounted vertically it would be more resilient to shocks because you wouldn't be risking having the heads crash onto the platters if you hit a real hard bump/pothole..

no science, just my $.02

This is how I'm mounting my drives.

They should, in theory, be shockproof.

Sorry for the crude diagram.



The mounting strings are made of 1.5mm stretch magic (find it at a craft store)

I use something similar in my desktop PC for noise reduction, but only suspended from the top, which leaves them free to move side to side, no good in a car. I saw someone with a setup similar to this one in their desktop PC, lemme see if I can find the pic

Here we go

I still think car cd changers have the best idea for shock absorbers. They use 4 silicon filled shock absorbers at each corner of the case and two springs to pull it back into place after vibration.

Last year I had some halt(hyper acelerated life test) testing done on a PC with 250 gig crap-xtors. During the vibration testing the hard drive would frezze up at 1G. Which is earths gravity. This system was constantly writing data to the hard drive which made it easy to see it crash.

Anyways, I would Prophesize that all hard drives act this way. Im no expert on it so dont take my word for it.

Here's the deal folks. Unless you're trying to run a SCSI or SATA Raptor-level drive in your trunk, there's really no need to worry so much about how to mount it.

Your car's shocks will take care of the bulk of any hard jolts that the car may otherwise experience. Your hard drive can handle g-shocks severe enough to just about break your arm if it were to experience the same force, so in light of the fact that THAT level of force isn't experienced in everyday operation, there's little chance of the head impacting the platters when the drive is mounted horizontally.
The idea behind mounting the drive vertically was this: take a bicycle wheel off a bike and spin it in your hands, holding the wheel as if you meant to lean down to the ground and go somewhere with it. Now that it's spinning, move it around. You feel that pull? The wheel is generating its own gyroscopic force that resists change of direction as long as the wheel is spinning. The wheel is also undergoing a kind of "flexing" force as you move it around. In a spoke-reinforced wheel, this force is no threat. In a flat platter, or series of stacked flat platters, this force has the potential to cause the discs to flutter and flex, causing the platters to run right up into the head.
There are two reasons why this is exceedingly unlikely to ever happen in your car:

1) The platters are very lightweight and small, and they only spin at about 7,200RPM. Yes, that's pretty fast, but factor in the small size and weight of the discs, and it becomes apparent that at that speed, the discs don't suffer from flex stress to any large degree. So, when you turn a corner or change directions, while the drive still undergoes those forces, the platters will not flex in any measurable degree, not even when driving over a pothole.

2) The heads are not held over the platters. They "float" on a cushion of air generated by the spin of the platters. Therefore, even if the platter were to flex to an alarming degree, the heads will likely ride that wave, safely above the platters at all times.

Beware of any comparisons to shock-mounted CD players. You need to remember that in a CD player, the read head is held in a static position, while the disc spins. CDs, being made of simple plastic, flex very easily, and ARE subject to flex flutter experienced during pothole hits. This flexing isn't normally drastic enough to cause any damage, but it will cause the laser to lose its tracking, and the song being played will skip for a moment before the stream is picked up again. THAT is why they shock mount CD players.

Now, having said all THAT, if you still decide to shock-mount your drive, you will need to come up with a method that does not allow the body of the drive to oscillate. That is, the drive should not simply be suspended in a loose springy fashion. Any vibration caused by a pothole or even the drive itself will in time potentially amplify itself, causing the drive to be under a constant flex stress. You want the drive to be mounted to a stiff shock frame that will help distribute the intensity of the shock, and then immediately return the drive to a static state. The best shock frame available is already in use: the computer's case.
If you want to give the drive another level of protection, probably the best way that I've found is to place a piece of foam rubber underneath the case, and secure the case down on top of the foam, compressing it. Small cargo straps over the case to hold it down on the foam have worked best for me so far. The foam will absorb the bulk of any extreme sudden shocks, but the compression of the foam will prevent the case from oscillating as it bounces on the foam.

Just a little basic physics common sense here.

Now there ARE two situations where you might want to be concerned about flex force to the degree that people seem to be here:

1) You are running a SCSI or SATA-converted SCSI (Western Digital's Raptor, for example) drive, which spins at 10,000 or 15,000 RPM. These drives, spinning at the higher rate, will experience the flex force to a greater degree. How much greater, and how nasty a threat is posed to them I cannot say, since those drives are ridiculously expensive and I will not run the risk of losing one.

2) Your vehicle gets into an accident. In this case, no amount of shock mounting or creative positioning in the world is going to improve your chances. It all depends on how the force of the impact travels through the car's frame, which direction it comes from, relative to the hard drive's position, and how hard the initial impact is.
From a personal standpoint, I had a Dell Optiplex GX100 computer with a Quantum Fireball 20GB 7200RPM drive sitting loose in the trunk of my Eclipse when the car was hit from behind and shoved into the car in front of it. Very serious impact. In fact, it was enough to make my body stiff for a week. The car itself was still driveable, but what impressed the crap out of me was that the computer, which had been hooked up and playing some tunes for me at the time of the accident, kept right on going.

That was about 4 years ago, and the hard drive is now happily spinning away in one of my secondary home computers.

Hopefully I helped tame down some of the debate, because it's really not as dire as some people would have you believe. With today's drives, mounting them using some complex specialized method isn't going to help them live any longer. With the way some of them are built, some of them will die from defects anyway.
You want to lessen the impact of a potentially-failed hard drive in your car? Use a drive you didn't pay very much for, or one that you don't care if you lose. Don't spend all your dough to build a system more powerful than the one in your room. That's like putting all your eggs in one basket, then taping the basket to a formula one race car.

Okay, I'm spent. That's enough for one day.

Cheers!