Page 1 of 1

HDD suspension: best elastic material?

Posted: Sat Jan 24, 2009 12:53 am
by SeanTek
What is the best elastic material for use with HDD suspension? I have been trying to silence several hard drives (3 Western Digital WD5000AAKS, 1 Samsung HD103UJ) in a Cooler Master Cosmos RC-1000 case following this method: viewtopic.php?p=448385, which uses Stretch Magic 1.8mm diameter. However, it is not working out for me. Firstly, the drive bay rails are too sharp, causing fatigue in the Stretch Magic cord.

I then placed some tape over all of the sharp edges of the drive bay rails. This method worked long enough to test two drives for up to about 2 minutes, but then one of the Stretch Magic cords broke in the middle of the cord, nowhere near the formerly sharp case edges. There was not an excessive amount of strain on the Stretch Magic cords either. While it worked, however, there was a noticeable reduction in case vibration and humming, basically down to inaudible.

Can anyone recommend a good elastic material for close-quarters HDD suspension? It cannot be much thicker than 1.8mm diameter; otherwise, I will not be able to thread the elastic cord around the rails. If no elastic material is appropriate, I would appreciate other non-destructive suggestions. I was using the Antec P180/P182 HDD grommets in place of the grommets that came in the Cosmos. These grommets reduced the vibration somewhat but I think it is counteracted by the fact that some of the hard drives make contact with the case or other metal sleds, due to the different size of the Antec grommets.

Posted: Sat Jan 24, 2009 1:13 am
by victorhortalives
Knicker elastic.

Go to the nearest notions store or section of a department store and get a few feet of it (or ask your nearest female !). I've seen a variety of thicknesses available. Once you've tied it though it's usually impossible to untie - must be cut.

Posted: Sat Jan 24, 2009 4:46 am
by Sylph-DS
victorhortalives wrote:Knicker elastic.

Go to the nearest notions store or section of a department store and get a few feet of it (or ask your nearest female !). I've seen a variety of thicknesses available. Once you've tied it though it's usually impossible to untie - must be cut.
Seconded, clothing elastic does a pretty good job, and is probably the cheapest by far. You can get like 10 yards for 2 bucks.

Posted: Sat Jan 24, 2009 5:03 am
by JoeWPgh
Stretch Magic doesn't always hold a knot, so I don't trust it for an actual suspension. (For lashing something down over a block of foam, it's OK)

Clothing elastic will not only hold a knot forever, the width and texture of it 'grabs' the HDD pretty effectively if you can get it looped around the drive.

Posted: Sat Jan 24, 2009 12:51 pm
by SeanTek
How about shock cord, aka bungee cord or elastic cord? A lot of systems on the pics thread show bungee or elastic cords.

I see that 1/8" diameter shock cord (used for tent poles) is at REI for about 15¢ per foot.

And what about the longevity of clothing elastic?

Posted: Sat Jan 24, 2009 2:02 pm
by JoeWPgh
SeanTek wrote:How about shock cord, aka bungee cord or elastic cord? A lot of systems on the pics thread show bungee or elastic cords.

I see that 1/8" diameter shock cord (used for tent poles) is at REI for about 15¢ per foot.

And what about the longevity of clothing elastic?
If it holds a knot, sure, why not? As for the longevity of clothing elastic? I would only worry about this if your plan was to stick the computer in the corner and use it for 10 - 12 years without ever going back into it. At the rate of tech progress, clothing elastic will likely outlast everything else in the box.

Posted: Sat Jan 24, 2009 5:46 pm
by jhhoffma
I use bungees and zip ties now. However, I've used elastic cord (nylon) before with great success. Same effect as Stretch Magic but much stronger due to the woven nature of the material, so unless you slit it with a knife right through, it won't break instantly. If it starts to go, you'll know it will before you drop a drive.

Also, if you have a problem with your drive breaking the cord, use more strands.

Posted: Sun Jan 25, 2009 12:20 am
by colin2
This is from a McMaster-Carr order a little while back. It's basically thin bungee cord; the polypropylene protects against sharp edges. Worked great.


50 Ft. 8858T821
Polypropylene Covered Elastic Cord 1/8" Diameter, Black (Same as 8858T82)
$4.50

Posted: Sun Jan 25, 2009 5:33 pm
by SeanTek
Thanks all. I am currently using the fabric elastic (from Jo-Anns), and it seems to be working all right. I picked up some rubber & polypropylene elastic cord as well, just in case.

At this point, two of the three WD5000AAKS drives are working just fine. One WD5000AAKS has a distinct but very low volume hum. The other two are inaudible beyond general noise. As to the HD103UJ, I actually have two: one has a hum that fades in and out in about a 3-second cycle. The other HD103UJ may or may not have a cycling hum but if it does it is so low I cannot detect it. The one that can be heard, however, is rather annoying since it is now the dominant sound from the case. Has anyone else had this problem? I tried moving the drives around, and I am pretty sure it is the drive itself rather than its positioning in the case. Interestingly, the humming drive is very faint outside the case, but it must be resonating somehow along the case walls since the sound seems amplified, at least at certain angles.

Posted: Sun Feb 15, 2009 1:49 pm
by gud4u
Browse the women's hair notions department (dressed in a rain coat and dark glasses), and check the selection of women's hair bands.

Walmart, RiteAid, etc.

My drive is supported by two of them. Excellent isolation.

Hope this helps!

Posted: Sun Feb 15, 2009 9:17 pm
by yamahaSHO
I've never had a problem with Stretch Magic holding a knot. I tie it many times in a bunch of different ways, but out of 3 computers, not of them have failed me. I'm currently doing another HTPC build that I just put some Stretch Magic in a Silverstone SG02.

Posted: Mon Feb 16, 2009 6:20 am
by Ch0z3n
I've never had a problem with stretch magic. Just do a double overhand knot and put a dab of glue on it. I also took the washers from my p182 hard drive trays and have them sit under the hard drive edges so the vibrations wont damage the stretch magic. Maybe consider sticking some kind of rubber washers on the stretch magic then put them over the 'sharp parts' to keep it from cutting?

Posted: Mon Feb 16, 2009 7:50 pm
by signal64
I've recently checked a case I outfitted with stretch magic for four drives almost 2 years ago. It appears to have lost only some minor elasticity but is still very adequate and strong enough for the four drives.

I used two separate strands on front and back with their own knots to give it some backup in case one of the knots came loose or other failure occurred. Everything still looks good.

While it can be a bit of a pain to obtain (got mine at a crafts store) and takes more time to "string it" it has been the most effective method I've used to get rid of drive vibration.

Posted: Fri Feb 20, 2009 2:50 pm
by Koolpc
Sewing Elastic is really good.