Thread: Scion xB '06, in-dash Atom 330, Lilliput 889GL; details, pictures, links. Index: pg 1

Looking good so far!

Originally Posted by captcol

I have seen semi suspended type hard drive systems on custom builds before, alot seem to rely on rubber bands but with the heat generated I think this is less than ideal, I thought that a tray with hdd's mounted in, possibly with fan attached to tray if heat was an issue then mounted using a rubber (and this is where my english skills run out) thingy that looks almost like a rounded figure 8, the ones i have seen have a solid rubber section between the two "loops" have one end mounted to the case and the other to the tray thus hopefully minimising the vibration factor without giving too much free swing during major braking events, or mount the drives perpendicular to direction of travel of the vehicle.

Kind of like a smaller version of the rubber car exhaust hanger thingies ... I guess the same thing could be achieved with strips of rubber, that would have been much easier to type, would need to have some thickness and not be overly flexible ...

/end train of thought ramble

Do not suspend the HDD..... what happens is if you hit a bump that the shock will cause the HDD to bounce long after you hit the bump. If its a 2.5 HDD drive they are made for shock... alittle bump wont hurt the drive if the HDD is securely fastened and moves with the car. The reason they use 2.5 drives are because of their durability. If you are still concerned, buy a SSD.

Originally Posted by captcol

In retrospect that is a very good point, do not suspend but would still use vibration damping washers that are around for hdd

I just dont really think its needed. All my years on this forum I have never heard of a HDD dying because of shock from bumps. Now if you drive off road, then yea, It may be a big concern, but I cant imagine rdholtz going off road in his XB, and I dont even go off road in mine, which was built for off road. You'll wnd up coming up with a system that I do not think will really do anything.

Hard Drive Mounting

Originally Posted by captcol

I have seen semi suspended type hard drive systems on custom builds before, alot seem to rely on rubber bands but with the heat generated I think this is less than ideal, I thought that a tray with hdd's mounted in, possibly with fan attached to tray if heat was an issue then mounted using a rubber (and this is where my english skills run out) thingy that looks almost like a rounded figure 8, the ones i have seen have a solid rubber section between the two "loops" have one end mounted to the case and the other to the tray thus hopefully minimising the vibration factor without giving too much free swing during major braking events, or mount the drives perpendicular to direction of travel of the vehicle.

Kind of like a smaller version of the rubber car exhaust hanger thingies ... I guess the same thing could be achieved with strips of rubber, that would have been much easier to type, would need to have some thickness and not be overly flexible ...

/end train of thought ramble

For these drives, my only real concerns are support and vibration damping. The car isn't powerful enough to get me worried about acceleration, and only impact is likely to create a deceleration issue; if there's an impact, I probably will have a lot more to worry about than hard drive failure.

I like the "thingy" term -- I use that myself to describe undescribables. In the auto industry, I've heard those rubber thingies called "exhaust hangers" or "exhaust hanger donuts". They serve three functions in exhaust systems: system support, vibration damping, and thermal expansion compensation (can you tell I used to design exhaust systems?).

The kind you mentioned is the double donut, and that's a pretty good way to go; I could actually get pretty close to a miniature double donut by just using an O-ring twisted into a figure 8. I'd probably have to figure out a way to get some lateral motion damping, too, possibly by mounting one pair for lateral damping and the other for vertical damping.

I'll start by trying the Velcro because it's so easy to use. If the Velcro doesn't provide enough vibration damping, I could mount the Velcro on a thin layer of foam rubber (a mousepad would be a good source) which I'd glue to the bottom panel of the chassis.

If that doesn't work to my satisfaction, I'll take a serious look at your donut idea. It would require a simple bracket -- very similar to the one I'll use for the Velcro -- and some longer hard drive mount screws so I could add some washers.

The more I think about it, the more I like your donut idea. Hmmmm -- time for some thinking . . .

Originally Posted by HiJackZX1

Do not suspend the HDD..... what happens is if you hit a bump that the shock will cause the HDD to bounce long after you hit the bump. If its a 2.5 HDD drive they are made for shock... alittle bump wont hurt the drive if the HDD is securely fastened and moves with the car. The reason they use 2.5 drives are because of their durability. If you are still concerned, buy a SSD.

I agree that I don't want it bouncing along all over the place, but that can be pretty well eliminated by making the donuts pretty tight, so they're shock dampers as well. Using Velcro takes care of that automatically.

Originally Posted by captcol

In retrospect that is a very good point, do not suspend but would still use vibration damping washers that are around for hdd

Originally Posted by HiJackZX1

I just dont really think its needed. All my years on this forum I have never heard of a HDD dying because of shock from bumps. Now if you drive off road, then yea, It may be a big concern, but I cant imagine rdholtz going off road in his XB, and I dont even go off road in mine, which was built for off road. You'll wnd up coming up with a system that I do not think will really do anything.

You're absolutely right: I don't plan to go off road, but I have taken the xB over some pretty rough stuff, including the dirt roads that surround my sister's farm. Then there was the railroad crossing in Maryland that simply launched the car; the xB landed gracefully, but it was still a pretty good hit that might have damaged a solidly-mounted hard drive.

captcol didn't suggest that I suspend it; he said "semi-suspended", which is what hard-duty notebooks use. I think some sort of vibration damping -- beyond what's already built into laptop drives -- is a good plan. I still like the Velcro cushion plan, but I'll see what I can glean from these ideas.

Originally Posted by rdholtz

Hard Drive Mounting



For these drives, my only real concerns are support and vibration damping. The car isn't powerful enough to get me worried about acceleration, and only impact is likely to create a deceleration issue; if there's an impact, I probably will have a lot more to worry about than hard drive failure.

I like the "thingy" term -- I use that myself to describe undescribables. In the auto industry, I've heard those rubber thingies called "exhaust hangers" or "exhaust hanger donuts". They serve three functions in exhaust systems: system support, vibration damping, and thermal expansion compensation (can you tell I used to design exhaust systems?).

The kind you mentioned is the double donut, and that's a pretty good way to go; I could actually get pretty close to a miniature double donut by just using an O-ring twisted into a figure 8. I'd probably have to figure out a way to get some lateral motion damping, too, possibly by mounting one pair for lateral damping and the other for vertical damping.

I'll start by trying the Velcro because it's so easy to use. If the Velcro doesn't provide enough vibration damping, I could mount the Velcro on a thin layer of foam rubber (a mousepad would be a good source) which I'd glue to the bottom panel of the chassis.

If that doesn't work to my satisfaction, I'll take a serious look at your donut idea. It would require a simple bracket -- very similar to the one I'll use for the Velcro -- and some longer hard drive mount screws so I could add some washers.

The more I think about it, the more I like your donut idea. Hmmmm -- time for some thinking . . .



I agree that I don't want it bouncing along all over the place, but that can be pretty well eliminated by making the donuts pretty tight, so they're shock dampers as well. Using Velcro takes care of that automatically.





You're absolutely right: I don't plan to go off road, but I have taken the xB over some pretty rough stuff, including the dirt roads that surround my sister's farm. Then there was the railroad crossing in Maryland that simply launched the car; the xB landed gracefully, but it was still a pretty good hit that might have damaged a solidly-mounted hard drive.

captcol didn't suggest that I suspend it; he said "semi-suspended", which is what hard-duty notebooks use. I think some sort of vibration damping -- beyond what's already built into laptop drives -- is a good plan. I still like the Velcro cushion plan, but I'll see what I can glean from these ideas.

You know, now that I think about it, mine does semi-suspend. It sits on a plastic piece, which I notice has a slight flex to it.

More on Hard Drive Mounting

Originally Posted by HiJackZX1

You know, now that I think about it, mine does semi-suspend. It sits on a plastic piece, which I notice has a slight flex to it.

Everything helps, even just that little flexure. I'll probably mount the drives using the side holes; the screws in the hard drives would go through the blades of the bracket, and would be supported by rubber grommets, which would provide a little cushioning. If the drive brackets sat on Velcro, that would provide a second level of shock damping; a foam base under the Velcro would provide a third level, but -- for a non-off-road vehicle like the xB -- would probably be unnecessary. I'm thinking of building it for the extreme just to demonstrate it, and maybe to test the theory.

Fastener Space Needed

Putting the chassis in the dash for the first time had some interesting results. It fits, but the fastener heads on the sides make for a tighter fit than I'd like, and I think that should be easy to remedy without major work.

Changing to 6-32 countersunk-head screws would do the trick; using them instead of the case screws would make the exterior relatively smooth. But the downside of using countersunk head screws is the need to make the countersunk holes just the right depth, and that really takes a drill press.

In the spirit of building this chassis with only simple tools, I'll go instead to flat panhead 6-32 machine screws, which have a much lower head. The almost-no-head-depth version of them is pretty common -- you'll frequently find them used in mounting hard drives. I'll zip over to our store and grab a bunch. You can probably get some from your local computer store for pretty reasonable money -- if they don't just give them to you.