Question How to avoid resonant vibrations of harddisks in a case?

[colettina]

I have an old LianLi case, built with pure aluminum and I like it. When my old computer died from a flash, I built my new computer in this case.

The case has a kind of cage for three harddiscs which is mounted with 4 screws to the front of the case. The HDDs are fastened by screws with rubber rings, which will isolate the disks from the cage a bit in order to reduce noise transfer to the cage.

When I placed one 1TB HDD in the cage, everything was OK. Then I added a second HDD, a 8 TB WD HDD. After that, the entire cage with the disks started to resonate at about 120 Hz. The vibrations are not only very audible and not acceptable. The vibrations are even so strong, that they can clearly be felt when touching the closed case and they are very strong, when I touch the cage for the disks.

I fear, that such strong vibrations will shorten the life of the HDDs. So I tried to set the HDDs at different places within the cage. But at any placement, the vibrations are going on and the are at 120 Hz at any placement. Further I tried to fasten the cage at the case with rubber dampers. But the vibrations were still there and again at 120 Hz.

It is not a problem of the HDDs themself because when I insert them in an external USB-case, there is no noise and nearly no vibration.

I have taken some photos of the situation, but I don't see, how I can make them available here and I have no account at the repos, for making the images accessible via URL. The three images are here:
Case side view and hdd mounting in the cage and hdd mounting screws detail

Constructive ideas welcome, how to get rid of this!

 

[Lutfij]

When I placed one 1TB HDD in the cage, everything was OK. Then I added a second HDD, a 8 TB WD HDD. After that, the entire cage with the disks started to resonate at about 120 Hz.
Might want to include the make, models and age of the drives you're working with.

I have an old LianLi case
Is there any sticker or barcode to help identify the case? If not, please pass on images of the exterior of your case.

On that note,
The vibrations are not only very audible and not acceptable.
the case you have was probably in an era when drives weren't as large of a capacity and weren't accessed as frequently as they are now. Coupled with the fact that the case's construction likely being full aluminum is contributing to your noise. To add, the construction of the drive cage/caddy is also causing resonance.

It is not a problem of the HDDs themself because when I insert them in an external USB-case, there is no noise and nearly no vibration.
Take all of the drive out of the case and run them on the bench top, you're likely not going to hear anything. I would advise on getting a case with sound dampened panels, like those on Fractal's Define series.

 

[colettina]

Thank you for your reply!
If I could be more precise about the LianLi case, I would have posted it here. I only can post some more pictures via links to my web space.

The HDDs are a WD 6 TB which has been sold as part of a NAS. Perhaps that is the reason, why there is no label on it. I assume, that it is a WD black.
The second HDD is a 1 TB Seagate Seahawk

I have bought this case at Caseking in 2016. But it isn't in production anymore / not available any more.

 

[Misgar]

I have around half a dozen old Lian Li Aluminium cases and one of them contains ten 3.5" hard disks (8 x SAS, 1 x SATA, 1 x IDE). I can barely hear the drives above the noise of the cooling fans, so I suspect you may have some rather noisy drives with out-of-balance spindles.

I have a 4TB Toshiba N300 NAS drive that developed bad sectors after 6 years and which buzzes like mad. The remaining 5 (identical) 4TB drives in the RAID-Z2 array are almost inaudible, unless you get close up to the computer.

If your drives are old and second hand, or you're just plain unlucky, you might have a perfectly good (but noisy) drive. Alternatively, like my 4TB N300, your drive might be failing.

Lian Li's rubber bush isolating screws are not 100% effective in eliminating vibration. In one of my old cases, probably a Lian Li V2000, I applied sheets of Bitumastic sound deadening material to the side panels and the drive cages. This came in the form of large sheets, about 1/8" (3mm) thick. The result was partial success, but not complete silence.

Professional drives intended for use in arrays of more than 8 disks, may include RV (Rotational Vibration) sensors, to compensate for vibrations from adjacent drives.
https://hothardware.com/reviews/sea...da-pro-12tb-hdd-and-synology-ds918-nas-review

The "easiest" solution might be for you to find a quieter drive, but that entails spending money which is not ideal. I find slower 5,400 drives are often quieter than 7,200rpm drives. These days, I only buy CMR, not SMR.

Suffice to say I have a collection of ancient Lian Li cases dating back to 2006, with between 6 and 10 hard disks each and I don't find drive noise detectable. All I can hear is the noise of the cooling fans, until I remove the side panels and place my head close to the drive cages. Then I can hear motors gently humming and heads clicking.

You may just be unlucky with your choice of drive, or it might be going bad like my 4TB NAS drive.

 

[colettina]

Thank you for sharing your ideas to the vibration problems. – Meanwhile I kept experimenting with different solutions and ideas.

First of all is my observation, that the same hdds, which will produce vibrations in the LianLI case, will run nearly noiseless and without any vibrations in a simple aluminum usb case from Inateck. And in the Inateck cases, there is no damping, no special or ruggadized construction, no trick.

Then I simply laid the hdd on my desk and connected it to the supply voltage only. I could barely feel some very slight vibration, but nothing else.

My conclusion: If there are a lot more vibrations, then ist must be due to some resonant effects. And this has to do with the LianLi case and the hdd cage in it. Therefor I focus only in measures, which can prevent resonant vibrations.


Now there are there are (at least) three ways to avoid those vibrations:
First is, to increase the coupling of the hdd to the case. But this will only lead to success, if the case is very stable.

Second (and perhaps in conjunction with the first) are measures to increase the moving masses. By this, the resonant frequencies can be lowered to be non multiples of the main resonant frequency like 120 Hz at hdds with 7.200 rpms.

Third measure is absolutely the opposite: Try to decouple the hdd as much as possible, like fastening ist by thick foam, rubber etc.

All my trying with the first two concepts were not successful. It seems, that there is nor way, to get such a lightweight construction silenced. I took a self adhesive foam 1 cm thick, which is available e.g at 3M and cutted four blocks of only 1cm length. Then I mounted four small 90° degree aluminum angle brackets in the hdd cage and on these the four foam pieces. Then I placed the hdd on these foam pieces by adding a double sided adhesive.
The only disadvantage of this construction is, that you should fasten the hdd, before transporting / moving the computer in order that the hdd would not come off of the glued strips.

The success, I achieved: Nearly no noise from the hdd any more!!! And the case keeps silent.

If someone likes to add on further ideas, how to decouple hdds completely from the case and hdd cage but would secure the hdds even when transporting the computer, this would be great!!!

 

[Grobe]

So, if I understand your solution - You filled the empty space between the outer wall and the metal plate that hold the HDD in place to mechanically lock the metal in place.

Sounds like the most reasonable fix for the problem

 

[kanewolf]

The basic answer is one of two things. Isolate the vibration from other things. This is the rubber mounting methods that isolate the disk. The other is dampen the vibration. That sounds like what you did by adding material that prevented vibration.

 

[colettina]

I have created a small graphic to show, how I realized the isolation. Yes, @kanewolf is right with his assumption. I have not found any solution in the web which could be bought.