HI Again,
For us who have built many systems over the years, having a good supply of those little brass spacers is not a problem.  An ample supply comes with every new case,,,,, enough to mount even the largest 'full sized' mother boards.
What is a problem is that many case manufacturers use the spacers with fine threads, which will NOT screw into the holes on the bottom of the drive.  And yet some makers use little shiney metal clips and not the brass spacers at all. 

So I'm quickly running out of the 1/4" brass spacers that have the course threads on the male end.

I don't see that as a problem though,,,, but just another inevitable fork in the road.
Sometimes we have to look beyond the obvious and whats right in front of us.

The whole idea is to get some space between the fan and the drive to avoid the "Air Dam" effect that occurs when the fan is too close.  Anything about 1/4" thick will do nicely.
Rubber spacers, or thin strips of balsa wood, or stacks of little washers and longer screws?

The day I finally run out of the 1/4" brass standoffs is just another day to "Get Creative". 

You'd be surprised what I do around here with a stack of beer coasters from my favorite watering hole.    Cut into narrow strips and glued together, I'm sure they'd make fine spacers.

Get creative, be happy and stay COOL!

Yous guys are the greatest!

The Doctor 

Rama,
Let me start by saying I LOVE your little saying under your name.
I used to have in my own Signature line, "The only bad backup is the one you decided NOT to make".

I was allowed to paw through the junk hardware box at "Cheap Guys Computers" one day, but only came up with five spacers of the right length and screw thread.
The male end of the spacer absolutely must have course threads in order to properly screw into the holes on the bottom of the hard drive.  The female side doesn't matter as long as you have compatible screws. 

Why the coolers are coming with 4 fine threaded screws is beyond me, if they intended for the coolers to be screwed directly onto the drives.  The threads just don't match.   Someone else had pointed that out in this forum.  Another one of life's little mysteries.

I see on different web sites like the one previously posted, that there are many different types of two-fan HD coolers.  Prices range from $9.95 all the way up to $19.95 for essentially the same thing.
I was elated to find the VIO coolers discounted down to less than $4 ea.
It's kind of like getting a "Big Mack" for $.25. (twenty five cents)

They all DO require some annual or semi-annual maintenance, like cleaning and oiling, but hey......
isn't that better than loosing hard drives and all the hassle that goes with that?

I've found that just one drop of fine machine oil, injected through the seal on the back of the fan motor once or twice a year is all that's required to keep those little guys running smoothly for years to come.  When I say "Injected", I mean with a hypodermic needle. 
I tried an insulin syringe, but the needle is too fine for the oil to freely flow through it.  You need something larger.  I use a syringe that came with an Ink Refill kit.  Works perfect!

Thus endeth "Fan Maintenance 101". 

The Doctor 

The temp after installation of fans on IDE drives runs at 92 degrees F and before it was hovering around 105 - 110 degrees F. Most noticeable was the how cool they are to touch whereas they were very hot before. I used a digital temp gauge to check the temp. Hope this helps.

/me 

The reader of this thread may also find the following articles of interest:

• ”Information about fans” and “Hard Drive Cooling” at The Heatsink Guide
• Temperature Limits and Drive Cooling

In addition, note that there exist hard disk cooling fans that require a minimal amount of vertical space when mounted:

• Thermaltake Hard Drive Cooler A2376:  height of 15 mm (0.6”)
• Hard Drive Cooler for 3.5" HDD:  height of 11 mm (0.4”)

Could fans such as these avoid the problem of using two drive bays to accommodate taller models such as the VIO Xper 3.5-Inch Hard Drive Cooler (0.75” or 1” with stand-offs)?

In 43 years as a field tech, I've learned to never rely on 'lab results'.
Labs are sterile, over controlled atmospheres where anything can be made to happen.

I worked with some of the best electronics engineers in the country at the "Caterpillar Research Labs" and I had to rework almost every circuit they came up with.  What works on paper, or values set using a slide rule, just don't work in practical application, like on a bulldozer working in a steaming hot swamp or above the arctic circle. 

So please don't tell me I'm wrong, based on some lame lab results.  OK?

I've worked on literally thousands of pieces of computerized equipment in so many different environments, you wouldn't even believe it.
One Rule I've found from 43 years of field service, is that:
1.   
2.   and lack of proper maintenance can take you right back to rule #1.

Stay , Stay SAFE! 

The Doctor 

What most folks who have not worked in the Electronics Industry, don't know, is that home computers are made of what we might call, "Hobby Grade" components.
They are made up of the lowest quality components from the lowest bidder.
Witness, the bulging capacitors on many motherboards.

They will only operate at temperatures comfortable to the operator.
If you're not comfortable at 120°F., then your PC won't be happy either.
Adversely, if you're not comfortable at 32°F, your computer won't be either.
For any home computer to 'live long and prosper' it should be kept at the same
temperature as an operator sitting there in a short sleeved shirt.

The last HD that failed on me was several years ago, before I started using two-fan coolers on every drive.  When I reached in to remove it, it was like removing a fresh baked potato from a hot oven.


To say that it was "Too Hot To Handle", is a gross understatement.

I was setting up a new HD on my bench a while back.  It was sitting upside down, with the motor hub and logic board facing up.  After partitioning and formatting the drive, it was "Too Hot To Handle".
I stuck on one of my Two-Fan coolers and within just a few minutes the drive was back down to room temperature. 

The shock factor, of a circuit board getting that hot and then cooling off when the drive is shut down can (in time) rip the circuits apart.  Keeping it always at room temperature eliminates all that expanding and contracting from damaging the drive.

Cheers!
The Doctor 

DrWho2006, although the results referenced in Reply #23 were produced by Google Labs, they are not "lab results":  rather, they are based upon actual usage of "more than one hundred thousand disk drives" that were "deployed in several types of systems across all of Google’s services."   The disks examined are "a combination of serial and parallel ATA consumer-grade hard disk drives, ranging in speed from 5400 to 7200 rpm, and in size from 80 to 400 GB."  If that does not qualify as "real world," then nothing does.

To interject some moderation to the discussion, I do not believe that anyone would disagree that temperatures outside of the design specifications stipulated by the hard disk manufacturer are harmful.  However, the axiom "if it isn't broken, then don't fit it" also applies here.  It would wise for a PC user to first monitor their hard disk drive temperatures, and if they routinely fall within the manufacturer's specifications, then adding a disk fan is not necessary – nor would any benefit arise from doing so.

P.S.:  DrWho2006, I would appreciate your viewpoint on the "low profile" (minimal height) fans described in Reply #22.