Attaching case fans via. nuts & bolts

[Elcs]

Sounds weird but bear with me.

Ive always put a bolt through both holes of a fan and affixed the nut at the end of the bolt.

Today, I was informed off someone on an IRC network (when I was searching for nuts and bolts to fit 38mm thick fans) that the nut was supposed to be on after the first fan hole.

Opinions?

EDIT: Changed 'screws' to 'nuts and bolts' in the topic.

 

[beatle]

My side case fan is attached with nuts and bolts. The bolts extends through both sets of holes on the fan.

 

[Elcs]

Originally posted by: beatle
My side case fan is attached with nuts and bolts. The bolts extends through both sets of holes on the fan.

and the nut on the end, outside the fan itself or after the first set of holes?

 

[Navid]

The harder you attach the fan to the case, the more vibration will be transferred from the fan to the case. The case acts as a resonator, in this case, and amplifies the noise. To minimize noise, you would want to attach your fans as loosely as possible!

That is why there are products like the Zalman bracket or rubber fan mounts.

Taking that into account, I do not see MUCH difference in placing the nut after the first hole or the second hole. But, if you want to be picky, you can say that placing the nut after the second hole will provide a little bit more flexibility.

Edit:
Fixed the first link.

 

[Elcs]

Originally posted by: Navid
The harder you attach the fan to the case, the more vibration will be transferred from the fan to the case. The case acts as a resonator, in this case, and amplifies the noise. To minimize noise, you would want to attach your fans as loosely as possible!

Im looking at adding vibration dampening washers in my setup. Just got to find what I want.

Taking that into account, I do not see MUCH difference in placing the nut after the first hole or the second hole.
Edit:
Fixed the first link.

Thank you.

 

[Jeff7]

No problems here. I've got some Evercool aluminum fans, which are nice, except that for whatever reason, they only accept standard fan screws on one side. I want a grille on the backside, so I use trusty 6/32 machine screws and nuts. Works just fine. Those little things are handy all over the place. I actually bought the boxes of 100 each (nuts and 1.5" screws), and I just use a Dremel to slice them smaller if I don't need the full length.

The harder you attach the fan to the case, the more vibration will be transferred from the fan to the case. The case acts as a resonator, in this case, and amplifies the noise. To minimize noise, you would want to attach your fans as loosely as possible!

Well, not too loose, or else you will wind up with lovely rattling noises instead of vibration.
I don't get too much vibration with my fans (good fans should be well balanced anyway and not vibrate much) but I still use Vantec's Silica Gel Vibration Dampeners. I might consider some of those isolation strips for bay drives. CDs are not always well balanced, and in the past, with cheap cases and loose side panels, spinning up a CD would sometimes make the entire side panel buzz.

 

[Elcs]

Originally posted by: Jeff7

The harder you attach the fan to the case, the more vibration will be transferred from the fan to the case. The case acts as a resonator, in this case, and amplifies the noise. To minimize noise, you would want to attach your fans as loosely as possible!

Well, not too loose, or else you will wind up with lovely rattling noises instead of vibration.
I don't get too much vibration with my fans (good fans should be well balanced anyway and not vibrate much) but I still use Vantec's Silica Gel Vibration Dampeners. I might consider some of those isolation strips for bay drives. CDs are not always well balanced, and in the past, with cheap cases and loose side panels, spinning up a CD would sometimes make the entire side panel buzz.

Wish I knew those Vantec things were good, came with screws and actually came with 2 dampeners and not 1 like I guessed. I could have ordered some along with my fans, got everything in 1 trans-atlantic shipment. Now to look for the Vantec things in the UK

 

[Jhhnn]

Doesn't really matter if the nuts are on the outer or inner fan ears- it's easier to have them on the inner ones, better access. I much prefer nylon insert nuts (nylocks) because they can't vibrate loose, ever, yet are still easy to install...

 

[Zepper]

Depends on the fan. If the fan mount points are floating ears then using just the one hole could help prevent warping the fan housing. But if there is solid plastic support between the holes on both sides then a thru screw is safe. Most folks are using the stubby little self-tapping screws that are made especially for fans and they only use the one hole. I just got some rubber fan mount pins (sunbeam brand) from jab-tech.com that I'll probably be using from now on. But they only work well on the floating ear type fans.

.bh.

 

[mechBgon]

Another couple of options:

1) tap the fan's holes with a metric 5mm x 0.8mm-per-thread tap and use 5mm x 0.8 bolts. Hit your local bicycle shop and ask for these, they're the size used for water-bottle braze-ons on bicycle frames. Some chromed ones with domed heads and 3mm hex-key fittings would look nice For plastic-framed fans, tapping is not strictly necessary but will make it easier.

2) if you can find them in the U.K. you could consider soft silicone-rubber fan-mounting thingamabobs.

 

[Zepper]

Hey mB,

I still intend to get you those pix. And you can get a dozen of the Sunbeam rubber pins for the cost of four of those at jab-tech.com

.bh.

 

[mechBgon]

Originally posted by: Zepper
Hey mB,

I still intend to get you those pix. And you can get a dozen of the Sunbeam rubber pins for the cost of four of those at jab-tech.com

.bh.

Excellent re: the pics, and thanks for the lead on the rubber pins! I got to check out jab-tech, they sound interesting :Q

edit: they have a CAFFEINE category?!?! I am there! :shocked:

 

[Elcs]

Originally posted by: mechBgon
Another couple of options:

1) tap the fan's holes with a metric 5mm x 0.8mm-per-thread tap and use 5mm x 0.8 bolts. Hit your local bicycle shop and ask for these, they're the size used for water-bottle braze-ons on bicycle frames. Some chromed ones with domed heads and 3mm hex-key fittings would look nice For plastic-framed fans, tapping is not strictly necessary but will make it easier.

2) if you can find them in the U.K. you could consider soft silicone-rubber fan-mounting thingamabobs.

Thanks for the heads up Mech but I ordered a set of those Vantec Vibration Dampeners that Jeff7 mentioned.

The fans I will be using are 120x120x38 Panaflo L1A's. Not exactly going to vibrate the case off the ground but I want to reduce noise in my case.

Anyone got any suggestion on how to determine what fans are making the most noise or what items are vibrating the most? Might as well use this thread some more.

 

[Navid]

A fan has a blade that moves at an RPM (revolutions per minute). If you divide that by 60, you get the frequency of the blade in Hertz. That is the sound you hear if the case resonates at that frequency. Of course, it helps if the fan is designed to be quiet. But, that only reduces the noise generated directly by the fan itself.
But, the fan still moves at the same frequency.
If the case resonates at that frequency, it will act as an amplifier!

Your question is a valid question. But, keep in mind that the quietest fan can still result in noise if not properly mounted.

 

[Tiamat]

foam double stick tape works wonderfully. It helps to minimize vibration. I bought a 10' by 1" roll of it and cut it into triangular pieces.

This is great if you have a 120mm fan in the rear, and a tall cpu fan that makes it tough to screw in the inner most fan holes.

 

[Jeff7]

Originally posted by: Elcs

Wish I knew those Vantec things were good, came with screws and actually came with 2 dampeners and not 1 like I guessed. I could have ordered some along with my fans, got everything in 1 trans-atlantic shipment. Now to look for the Vantec things in the UK

They also come with a bunch of little rubbery washers. Not too bad.

 

[Elcs]

Originally posted by: Jeff7

Originally posted by: Elcs

Wish I knew those Vantec things were good, came with screws and actually came with 2 dampeners and not 1 like I guessed. I could have ordered some along with my fans, got everything in 1 trans-atlantic shipment. Now to look for the Vantec things in the UK

They also come with a bunch of little rubbery washers. Not too bad.

Found them last night, got a PSU one as well just incase that turns out to be useful. Came to around £8 for a pack of 120mm and a pack of psu + first class delivery.

Fans didnt come today so perhaps they will come tomorrow along with my dampeners. Pity I didnt know or think about this beforehand, I could have got them from America in the 1 shipment.