Damping heatsink fin vibrations?

[DSF]

So I've been noticing the noise from my BTF-90 more now that I have an Accelero on my 8800GT. It's actually pretty annoying for a heatsink that's supposed to be quiet.

I googled the problem, and SPCR agrees that the fan has an annoying whiny character to its sound, partly caused by vibration of the heatsink's fins. Is there any good way of keeping the fins from vibrating so much, or from vibrating at that frequency?

Edit: Alternately, I'm completely happy to dial down the fan speed in Speedfan as the CPU runs cool enough for my taste. I can't seem to figure out how to do this though. Anybody able to give me a hand? It is possible with a 4-pin PWM fan, right?

 

[sonnygdude]

Hmmm, the dickerer side of me would piece together something involving a rubber band cut to make a strip instead of a band and secured across the fins perpendicular to them on both sides. The trick is making sure the rubber band will contact all the fins and not just ride on the high spots. Maybe backing it with something rigid like a thin strip of balsa wood backing the band and held in tension against the fins with tape (this would serve to compress the rubber strip)? You'd want good tape so nothing gets pulled off and sent flying around your case. Seeing as you're trying to damp the free sides of the fins you shouldn't have to worry about impeding airflow too much in such an arrangement.

Or, if you can get a rubber band around the whole shebang w/o interfering with the fan, just do that and use it to hold two strips of something soft onto the sides of the fins, like foam tape or something (wouldn't trust just the tape adhesive to hold it on, and you need something to force the strips against the edges of the fins).

An interesting and potentially engaging little project if you decide to try physical damping, good luck!

 

[DSF]

Yeah I was thinking of something along those lines. I think wrapping a rubber band around the whole thing would bend the fins near the top and bottom.

I'll have to ponder on this.

 

[Zepper]

A couple of beads of hot glue or silicone seal across the fins?

.bh.

 

[Team42]

DSF,

If the fins on the BTF-90 are loose, you could dampen them with homemade baffle. Get yourself some soft material 2 or 3 mm thick (such as double-sided foam tape - don't remove the backing strips though!) and long enough to reach from the bottom fin to the top fin. Cut deep nicks with a razor blade across the tape (almost, but not, the whole way across) which will allow the "fingers" of the tape to be inserted between the fins (I'd suggest one baffle between each pair of heatpipes). The material should dampen the movement of the fins which is causing the rattle.

As for configuring SpeedFan...

I haven't seen a good enough guide for it. I've tried using it myself, but it's not really intuitive. I gave up after a couple of days.

T42

 

[WoodButcher]

Originally posted by: Zepper
A couple of beads of hot glue or silicone seal across the fins?

.bh.

Silicone would do the trick. Buy a tube of aquarium sealant and cut the tip of the applicator for as small a bead as possible, apply, let dry and your done. I prefer "Goop" brand plumber's sealant over the aquarium silicone because the drying time is very short. If you can work fast and get a nice bead the first time I would recommend this otherwise go with the silicone. Don't try to clean the cobwebs until the stuff cures, silicone or goop, cut it off after or you'll make a mess of the rest of it.

 

[Rubycon]

Originally posted by: WoodButcher

Silicone would do the trick. Buy a tube of aquarium sealant and cut the tip of the applicator for as small a bead as possible, apply, let dry and your done. I prefer "Goop" brand plumber's sealant over the aquarium silicone because the drying time is very short. If you can work fast and get a nice bead the first time I would recommend this otherwise go with the silicone. Don't try to clean the cobwebs until the stuff cures, silicone or goop, cut it off after or you'll make a mess of the rest of it.

Goop is better although not as seemingly permanently elastic as RTV. If you use RTV make sure you use the stuff that does NOT release acetic acid while curing! For one the stuff will make your box smell like a douche bag! (seriously!) and second the fumes are corrosive. Goop (all varieties) are elastomeric copolymers with distillates of petroleum as a vehicle so the fumes actually smell "good" if you're into that kind of thing. (my fav is Magnum44 magic markers) :laugh:

 

[BonzaiDuck]

Originally posted by: Rubycon

Originally posted by: WoodButcher

Silicone would do the trick. Buy a tube of aquarium sealant and cut the tip of the applicator for as small a bead as possible, apply, let dry and your done. I prefer "Goop" brand plumber's sealant over the aquarium silicone because the drying time is very short. If you can work fast and get a nice bead the first time I would recommend this otherwise go with the silicone. Don't try to clean the cobwebs until the stuff cures, silicone or goop, cut it off after or you'll make a mess of the rest of it.

Goop is better although not as seemingly permanently elastic as RTV. If you use RTV make sure you use the stuff that does NOT release acetic acid while curing! For one the stuff will make your box smell like a douche bag! (seriously!) and second the fumes are corrosive. Goop (all varieties) are elastomeric copolymers with distillates of petroleum as a vehicle so the fumes actually smell "good" if you're into that kind of thing. (my fav is Magnum44 magic markers) :laugh:

You're a riot, Ruby. You may be technically correct about the acetic acid, but one would only need to let the RTV silly-cone sealant/adhesive dry out -- and no "vinegar in the computer-case." But -- Hey! -- I use GOOP, too . . . The silicone-rubber stuff may be a better sound-dampener, though. GOOP is second choice. Another compound called "Pit-Stop" is good for some other things, has "elastic" properties when dry, but worse than the first two choices.

 

[Rubycon]

Yes fully cured RTV is vinegar smell free. But something used right away after application to something that has a fan = WATCH OUT!

Personally if I had a cooler that was causing such a ruckus I'd toss it out.

 

[DSF]

Originally posted by: Rubycon
Yes fully cured RTV is vinegar smell free. But something used right away after application to something that has a fan = WATCH OUT!

Personally if I had a cooler that was causing such a ruckus I'd toss it out.

Haha, ruckus is probably an overstatement. It's not that bad. With any level of ambient noise, like if the fan for the A/C is on or if I'm gaming it's completely inconspicuous. It's just now and then when the machine is idling and the room is quiet. The reason I notice it now is that I've made the rest of the machine as quiet as possible.

I'd like to spend as little money as possible, and the cooler does a pretty good job, so tossing it would be an absolute last resort and would have to wait until I have a little more disposable income.

Edit: I really appreciate all the help.

 

[WoodButcher]

Originally posted by: Rubycon

Personally if I had a cooler that was causing such a ruckus I'd toss it out.

Sorta like evicting my ex,,,,,,

When you get old like the Duck and I, parts of your body don't work anymore or hurt when they do you'll learn the fine art of tinker.