QMicra from PC Design Lab: SFF Super-sized

Cases|Damping
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INSTALLATION

Lower Section

The easiest way to build the QMicra is from the bottom up. The top tray can be removed by undoing a few thumbscrews, leaving the main body wide open. With the exception of a few tall heatsinks, there shouldn't be many combinations of hardware that won't fit. Our test system used a sizable Zalman CNPS9500 heatsink that managed to squeeze under the upper tray.

Extreme performance enthusiasts should take note that dual graphics cards or any unusually long cards can potentially obstruct one or two of the hard drive bays. If you're buying the QMicra for a box-with-everything, you might want to reconsider your 4-drive RAID array. Regular users or anyone who cares about noise can ignore this problem. You won't want four drives in your system; they will make too much noise for the system to be very quiet.

Expansion cards fit easily into place, even after upper tray has been reassembled. Cards are locked into place by a plate that is secured with thumbscrews outside the case, where they can be accessed without a screwdriver at any time. This is convenient, but we worry a bit about the metal plate that clamps the cards in place — it had a habit of rattling whenever the system was running until we damped it with a piece of foam.


Access to the expansion slots is from the outside of the case.

We like the plastic-headed thumbscrews. These are intended for use with the hard drives and a total of 16 are included — enough for four drives. Our test system only had one drive, and we found that the spare thumbscrews came in handy for the motherboard and the power supply as well.


A fan splitter, lots of cable ties, and various screws are provided.

As noted, the QMicra ships without any fans, so these also need to be installed before the top tray is installed. A small strip of silicone tubing is included that can be used to make grommets for the fans or any other hardware that might benefit. We used them on the hard drive and the power supply as well as the fans. Unfortunately, the tubing is not especially soft, nor does it prevent direct metal to metal contact between the screw and the frame, so the grommets are likely to be of limited use.


A strip of silicone tubing is included so that damping grommets can be made...


...and the fan screws come with grommets already in place.

Upper Section

With the motherboard, CPU, heatsink, fans, and any expansion cards all in place, the upper tray can be reinstalled and the power supply and optical drives with it. Both of these are easy to install, as they can be laid into place from above and screwed into place with ease. However, the short length of the case may cause problems when both the drive and the power supply are longer than usual. The photo below shows the issue we had trying to fit an Antec NeoHE 430 power supply (1cm longer than standard) along with a standard optical drive. The shorter optical drive on top fit perfectly, and it is the one we ended up using.


Fit between the power supply and the optical drives may be a bit tight.

Hard Drive

The hard drives are the last to be installed. Installation can be as simple as hanging the drive from the harness by two thumbscrews. Multi-drive setups will benefit from screwing a bracket to the bottom of the drives to prevent them from making contact with each other, but this is only likely to be an issue in systems with three or more drives. In most systems, the extra bracket should not be necessary.

The problem with the extra bracket is that one end simply rests against the side of the optical drive bay, making it a point of potential vibration noise. This issue could be much ameliorated by the addition of a thin damping pad on either of the contacting surfaces. It's something that could be easily added by the manufacturer.


The harness flexes enough to provide some isolation from drive vibration.


With the bottom bracket attached and the HDD on the outside position, the HDD is still free to sway back and forth, with the bracket edge rubbing against the side of the optical drive bay. This would not happen when the case is stationary.

With the bottom bracket attached and the HDD on the inside position, the HDD is quite stable, with the bracket edge barely touching the side of the optical drive bay. If a second drive was mounted on the outside position, then the bracket edge would press more firmly against the upper internal platform.

Drive hanging in place without bottom bracket. This position caused the drive to bump into the filter below, so we ended up moving the drive to the inner bay, where it didn't hang so far inwards.

Ralf Hutter's Take on the QMicra's HDD Mounting System
Ralf Hutter is the nom de plume of a once-very-active SPCR writer who has extensive experience with metals from his occupational life. He had these comments to make about the aluminum yoke used as the HDD mounting bracket in the QMicra:

RH: I would not be entirely comfortable with the flexy HDD mounting bracket because of...
  1. the constant vibration effecting the drive, and
  2. the aluminum brackets hardening over time and potentially cracking
We asked, How is this any different from any other method of soft-mounting?

RH:
It is different from other methods of soft-mounting because it's only attached at one end and it "swings in the breeze," so to speak. Most every other soft-mounted HDD that I've ever seen is supported on at least two opposite sides, if not all four. And it's obvious that it is swinging because of the sagging that's apparent in the bracket. (RH refers specifically to the photo of the drive mounted without the bottom bracket, which is the way we installed it.)

We asked, Would the fact that the harness is anodized make it less susceptible to metal fatigue?

RH: Anodizing won't make any difference at all. There's sort of two types of anodizing. The first is for appearance (think of "bumper chrome") and the second actually "case-hardens" the surface of the metal to a depth of .002" or so (think "industrial hard chrome"). The first type is what you see on most consumer products. It can come in many various colors, but imparts no surface hardening to the metal. The second type (called "Type III" in the biz) actually provides a tough outer protective surface, but is not available in any color other than basic green-gray. The QMicra case is definitely not Type III anodized.

Aluminum is one of those ductile metals that work-hardens and becomes brittle. Maybe a HDD doesn't weigh enough to cause that to happen over time, but I wouldn't like to bet my drive(s) on it.

In light of RH's comments, if you expect to subject your QMicra to a lot of movement (ie, a LAN party gaming rig), it might be prudent to use the bottom bracket and mount the HDD on one of the inside positions. If the resulting HDD vibration transfer causes too much increase in noise, discard the bottom bracket and wedge in a piece of softish foam to support the bottom edge of the HDD(s) to keep the aluminum yoke from flexing as much. Mind you, it might be a long time before the aluminum could become stressed enough to crack or break.


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