Source for DIY 3.5" bay enclosures?

Syzygies

Senior member
Mar 7, 2008
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Has anyone spotted a source for empty 3.5" bay enclosures, for DIY projects?

I'd like to experiment with various DIY fan controllers. My 3.5" bay (where the floppy would go) is my free bay, and big enough. I've been to what I consider all the usual sources, and inexplicably I've never seen such a thing for sale.

For that "retro" look and a perfect fit, I may mod internal floppy drives. The price is right, but this is Dremel work I'd rather skip.

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In a past life I made headphone amps. An amusing problem was to devise a charging circuit for 12V of NiMH batteries using only an iPod charger, which provides barely more than 12V. Traditional charging circuits have a several volt overhead. I read "The Art of Electronics" and got very interested in current mirrors. With help from a DIY headphone amp forum (advice on stabilizing the current mirror given the variability of transistor specs), I devised a charging circuit with very little voltage overhead. Basically, the same waste is there, but sideways: One current path is regulated anyway one likes and thrown away, and all the other current paths mimic the same current, and are fed to the batteries. The only significant waste is the regulated path.

I had thought that this circuit had only a very obscure application, until I noticed that "active" fan controllers generally top out at 10.75 volts, because of a similar overhead.

I'd like to play with this. Here, the control path could feed a lower amperage fan rather than being thrown out, the other paths could feed my other fans, and there would be little waste.

Using diodes is of course simpler, and doesn't dump that much heat compared to a Q6600. But I miss analog electronics; this would amuse me.

Edit: Fan Noise Solutions is a great site, very comprehensive, for DIY fan controller designs. They include an active design with very little voltage overhead, that I'd prefer to my current mirror.
 

bigpow

Platinum Member
Dec 10, 2000
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you might want to start by getting cheap 3.5" memory card readers (used).
I built my own kamabay using aluminium sheet (with black rubber face on one side) folded on two sides and drilled a hole for an 80mm fan, this went inside 2x 5.25" bay.
I suppose you could also do it using metal sheet (fold it using hard surface to make sharp crease)

Fan Noise Solutions is a great site indeed.

the only thing I tried was the easy 7V mod, which made my PSU very unhappy.
I've been thinking about using 2x 12V fan in series, that'd safer than 7V mod, wouldn't it?
 

Syzygies

Senior member
Mar 7, 2008
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Originally posted by: bigpow
the only thing I tried was the easy 7V mod, which made my PSU very unhappy.
I've been thinking about using 2x 12V fan in series, that'd safer than 7V mod, wouldn't it?
That's interesting, maybe I'll skip the 7V experiment. Perhaps it depends on the power supply, there are many ways to wire (multiple or single or fake multiple rails etc) the internals of a supply.

I like the diode idea, I just picked up a bunch of 3A diodes at Fry's. All my fans come out of a single Sunbeamtech Multi Fan Power Port
(a few Y adapters to handle eight fans) so I can step them down all at once with a short modded power extension cable, or a rotary switch hooked up to various diodes.

Two 12V in series would be 6V, that's not much.
 

bigpow

Platinum Member
Dec 10, 2000
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i also didn't get it. i've done 7v mod since 10yrs back, and it was always ok.
then, i got myself a really nice PSU (seasonic s12-600), and it got busted out of the blue.
I even had to RMA the PSU back to Seasonic.

Long story short, I'd never do another 7V mod with a nice PSU.

6V is what I have running in my system. YL 120mm at 50% (via speedfan), the same yate loon can start from as low as 5V.
 

Zepper

Elite Member
May 1, 2001
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You might be able to use the rails from this (notebook drive adapter): http://www.geeks.com/details.asp?invtid=HD-108&cat=HDD --to mount a PCB and use your bay filler plate for the front panel. Or maybe you could find a project box of similar dimensions to a floppy drive that would mount right in. I've never seen one made specifically for a 3.5" bay. Someone makes a storage box/drawer for a 5" bay, but I've not seen a project box specifically for a 5" bay either.

See the mouser catalog - it has a bajillion project boxes.

.bh.
 

Syzygies

Senior member
Mar 7, 2008
229
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Originally posted by: Zepper
and use your bay filler plate for the front panel.
Yes, I got email back from Antec, the "3.5in cover" is $2.50 each plus shipping, call Antec. The cover snaps in place, somewhat, so the bent metal behind it might do the trick. I'll chase down these other leads, too.
 

cpemma

Member
Dec 9, 2000
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Originally posted by: bigpow
i also didn't get it. i've done 7v mod since 10yrs back, and it was always ok.
then, i got myself a really nice PSU (seasonic s12-600), and it got busted out of the blue.
I even had to RMA the PSU back to Seasonic.

Long story short, I'd never do another 7V mod with a nice PSU.
I've also done it for years no problem, most recently with a Seasonic S12-430. It's just taking advantage of voltage being potential difference, so I can't understand how problems can arise, however the PSU is designed, providing the power supply is powering a system and not just a 7-volted fan. The unwanted 5V has to flow to 0V through some 5V components.

But these days I wire a 5.1V (or to suit) 1.3W zener into the fan red wire, it gives the under-volting to silence my Yate Loons and the speed signal still works.