hdd mod (in the box)

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
Hey ya'll I was inspired by a mod I had seen on www.SilentPCReview.com. The mod outlined a way to effectively shut up a hard drive while cooling it at the same time.

here's the Mod http://www.silentpcreview.com/modul...ns&file=index&req=viewarticle&artid=11&page=1

I used 1/4" steel welding plates for mine... and i had to cut mine myself :cry: :cry: :cry: but it effectively got rid of the whine of this 800JB... too bad it doesn't have an internal temp sensor like my other drives... i think im gonna stick a thermometer in there to test it later on :eekers:

The review has some spectral graphs, I've tried to emulate them...

Sound measurements taken from 2 away.

Sound measurements taken from 12 away.


So it looks like I've eliminated a chunk of sound in the 3-4khz range and reduced some of the sound in the range from 10-20khz... I wish I could accurately measure the sound without the HDD running for reference, but it's my boot drive.

Just to give you an idea here are the before and after sound files:
Before
After

These sounds are almost 100% the way my ears hear the sound when im using the computer... im sure you'll have to run them up to get a good idea of what frequency the 800JB was making.

{Edited to convert pictures of excessive size to URLs. Please be kind to modem users.}
 

Jan Kivar

Learning Storage Performance
Joined
Feb 3, 2003
Messages
410
Could You run it without the box and measure the temp?

Jan
 

Mickey

Learning Storage Performance
Joined
Mar 4, 2003
Messages
139
Location
Left Coast
blakerwry, how did you do the measurements? I've been wanting to do something similar at home but all I have is a Radio Shack SPL meter.
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
im working on it mickey... in the interum, here are the pics of the steel sandwich...

http://www.anime-jennie.com/hdd/sandwich/steel sandwich pics/

I've learned a few things...

1) The steel must have firm contact (pressure) with the foam on the sides... if the steel is not tight enough onto the foam then sound leaks out.... my wire is not good enough.. I will need bolts or screws.

2) My foam is too rigid and cannot be compressed so that the top layer of steel touches the HDD(there's about a 1/4" gap), I need softer foam... maybe carpet padding would be better.

3) Without the HDD touching the steel heat is not dissipated fast enough and the drive looks to be heading towards overheating.
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
oh, and another thing... this thing *BARELY* fits into my case... if it were 1/8" wider it would not fit at all. This is why I put tape on the one side (serves as electrical insullation)... and also why I used wire instead of bolts.

If I had a larger computer case where eithermy mobo didn't goto the bottom of the case or i had more room infront of the mobo then I could easily put this thing in the case without worrying about electrical short circuits.
 

Mercutio

Fatwah on Western Digital
Joined
Jan 17, 2002
Messages
21,607
Location
I am omnipresent
I didn't pick this thread up until just now. Looks like you're really on to something Blake...

Are you doing any experimentation with different types of foam?
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
i wish i had some more carpet padding, I used about 30sq ft of it in my car a few years ago, but i cant find any scraps.

carpet padding is just scrap foam that has been cut up and pieced together into a sheet... much the way "chip board" is made. It is used in houses between the carpet and the ply wood flooring to act as a cusion and as a sound insulator... i think it comes in 3/8th's, 1/2, and 5/8th's inch thicknesses.


it's an ok sound insulator... but is compressable and would probably serve the purpose much better than the foam i am using now... hehe.. the foam I have now is actually from a "noodle"... one of those swimming pool toys... it's very hard and probaby allows no airflow or heat transfer. pretty poor.

I can pick up some carpet padding wednesday from the carpet store.


about temperatures... I ran the computer for about 45 minutes with the HDD mounted normally.. I got a temp of 97.2 F

here's what I got with the drive in the sandwich
Code:
Time(min)    Temp(F)
0            98.3
30           102.7
60           106

After the drive reached 106, i figured I didnt want to wait for it to reach 110F... so i stopped the test.


I measured these temps using a Mabis Healthcare Inc Thermometer for checking human body tempurature. I placed the tip of the thermometer in the middle screw hole on the right side of the drive.
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
For sound testing I used a trial copy of SpectraPlus232, utilizing my plantronics LS One/.audio60 microphone and Fortissimo II sound card. The mic was at about 90% recoding level with the "mic boost" turned off.

I conducted 3 tests with the sandwich and 3 without, changing distances every test. Each test lasted 5 seconds. The graphs show the maximum sound level reached during that 5 seconds... this was as close to an average as I could get...

I composited graphs using photshop to make them easier to compare.
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
Since i am interested in relative sound vs absolute sound levels (I'm comparing the same computer system and only changing one variable - not trying to compare my results with the results of others), I didnt care to use fancy equipment or to calibrate my mic... for what I am doing, this should work great.
 

jtr1962

Storage? I am Storage!
Joined
Jan 25, 2002
Messages
4,184
Location
Flushing, New York
Very intriguing. This is definitely something worth trying. If the sound is really damped because of the sheer mass of the plates, probably lead sheets would work best of all. Lead is also fairly soft, so it should be easier to work with than steel or aluminum. In fact, if you needed to make a bunch of these out of lead, you could make a mould out of plaster of paris, melt the lead, and pour it. In my experience lead is a very good sound dampener. I fill all the space inside the plastic body shell of HO locomotives with lead to increase tractive effort, and as a bonus this cuts down on motor/gear whine.

PC case makers could essentially accomplish the same thing with much heavier gauge drive bays, perhaps in conjunction with isolation mounting and surrounding noise reduction material. Considering that most modern hard drives aren't noisy to begin with, these things could make them virtually silent.

Now on to the rest of the equation. Let's start taking the heat from the CPU, power supply, video card, and chipset via heat pipe to a big passive heat sink on the outside of the case. This will eliminate the need for any fans at all.
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
I decided to make a cardboard sound dampener... USPS priority all the way baby!

pics:
http://www.anime-jennie.com/hdd/sandwich/USPS/

Sound measurements with the 800JB.


As you can see, even the cardboard USPS box made an improvement... I tested with the old 2200 caviar and it was a HUGE improvement.. but still not as good as the steel plated sandwich.

*These measurements probably shouldnt be compared with the previous ones becasue i have adjusted some of my fans in my case.

{Edited to convert pictures of excessive size to URLs. Please be kind to modem users.}
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
jtr1962 said:
Very intriguing. This is definitely something worth trying. If the sound is really damped because of the sheer mass of the plates, probably lead sheets would work best of all. Lead is also fairly soft, so it should be easier to work with than steel or aluminum. In fact, if you needed to make a bunch of these out of lead, you could make a mould out of plaster of paris, melt the lead, and pour it. In my experience lead is a very good sound dampener. I fill all the space inside the plastic body shell of HO locomotives with lead to increase tractive effort, and as a bonus this cuts down on motor/gear whine.

PC case makers could essentially accomplish the same thing with much heavier gauge drive bays, perhaps in conjunction with isolation mounting and surrounding noise reduction material. Considering that most modern hard drives aren't noisy to begin with, these things could make them virtually silent.

Now on to the rest of the equation. Let's start taking the heat from the CPU, power supply, video card, and chipset via heat pipe to a big passive heat sink on the outside of the case. This will eliminate the need for any fans at all.

Where am I going to get ~15lbs of lead? (14.748593449619923 lbs to be exact)... The steel weighs about 10.2 lbs (minus the material lost in cutting) as is...

One problem about WD's current drive design is that it is impossible (without making a mold) to get the top surface of the drive to have more than maybe 5% physical contact with a large flat sheet... this is because of a ridge that does around the top of the drive...

anyway I look at it cooling is tough for the WD drives.. I have thought about mounting metal to the sides and having the metal also contact the top and bottom plates...
something similar to this...
http://www.silentpcreview.com/files/images/hd_cooling/hd_side-hs.jpg
placing the plates on top and bottom of these side pieces... for maximum conduction...

there's also air or water cooling using a small water block that fits inside of this groove... but air is noisy and water is a whole nother project...

I think when my 120GXP comes back from being RMA'ed I might put it in this rig and put the 800JB in a room i dont have to sleep in.
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
OK, i would just like to warn everyone that the USPS box was a BAD BAD BAD thing... I had been using my computer for a couple hours with the USPS box and decided to check how things were going in the box... the HDD was HOT... The computer was off, so I quickly reached for the thermometer... temp started off at 102... rising rising.. rising... stopped at 110.2 and held... aparently the thermometer's maximum...

I can only guess from the way the thermo was rising that the actual temp was somewhere between 112 and 116 fahrenheit... definately under 120.

After feeling how hot that is, i can say that it is probably a good idea to keep your HDD under 40C WD lists the drive's operating temp as 41°F to 131°F... however I dont think I ever want to go above 110 again!

if i repeat the USPS box again it will be with a 40-60mm fan blowing fresh air in.
 

Jan Kivar

Learning Storage Performance
Joined
Feb 3, 2003
Messages
410
I guess I should have posted that SilentPCReview's article yesterday. I wasn't quite sure how the sandwich was built. The sides of a HD conduct heat much better. Here's the link for the article: Effective Passive Hard Drive Cooling. For busy people: Just read the conclusion at the end of that page...

Cheers,

Jan
 

jtr1962

Storage? I am Storage!
Joined
Jan 25, 2002
Messages
4,184
Location
Flushing, New York
blakerwry said:
Where am I going to get ~15lbs of lead? (14.748593449619923 lbs to be exact)... The steel weighs about 10.2 lbs (minus the material lost in cutting) as is...

One problem about WD's current drive design is that it is impossible (without making a mold) to get the top surface of the drive to have more than maybe 5% physical contact with a large flat sheet... this is because of a ridge that does around the top of the drive...

You don't live anywhere close to a range, do you? :lol: I agree getting that much lead would be problematic and costly, but you could make an exact mold of the WD drive's top for a perfect fit. Not easily done with steel or even aluminum, whereas lead can be easily melted and cast on a stove or hot plate(I've done it). As a bonus, if you have enough drives, your PC will be too heavy for a thief to carry away.

Now for the ultimate in mass there's always depleted uranium. Some N-scale modelers use DU to weight their engines, but I haven't seen an advertised source for it. Probably pricey, and dangerous to handle, so I wouldn't bother with it.

Seriously though, I think you're on to something here. Keep us posted. :)
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
I read that, but i think it depends on the drive really... The old style caviar (WDAC 2200)has a completely flat top which means boku surface area... however the sides are ~1/4 plastic because of a seal... so not only is there less metal, the seal makes the side not flat... a double whammy...

the 800JB has a cast metal side and botom structure w/ a crappy surfaced top... making the sides more apealing...

blah, this drive is just getting to me now... I think im going to talk to my local reseller and see if he'll trade me something for it...


Heres the comparison audio files of the USPS vs non USPS setup. (from 2" with the case off)
Before
After




*I have changed fan setup so things are much quieter, making the HDD stand out SO much more clearly...

Changes include:

  • Removal of chipset fan
    Slowing of CPU fan from 2200rpm -> 1550 rpm
    Change from ~2000-3000RPM case fan to ~1000rpm case fan
    Change of VGA fan to 5v
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
jtr1962 said:
blakerwry said:
Where am I going to get ~15lbs of lead? (14.748593449619923 lbs to be exact)... The steel weighs about 10.2 lbs (minus the material lost in cutting) as is...

One problem about WD's current drive design is that it is impossible (without making a mold) to get the top surface of the drive to have more than maybe 5% physical contact with a large flat sheet... this is because of a ridge that does around the top of the drive...

You don't live anywhere close to a range, do you? :lol: I agree getting that much lead would be problematic and costly, but you could make an exact mold of the WD drive's top for a perfect fit. Not easily done with steel or even aluminum, whereas lead can be easily melted and cast on a stove or hot plate(I've done it). As a bonus, if you have enough drives, your PC will be too heavy for a thief to carry away.

Now for the ultimate in mass there's always depleted uranium. Some N-scale modelers use DU to weight their engines, but I haven't seen an advertised source for it. Probably pricey, and dangerous to handle, so I wouldn't bother with it.

Seriously though, I think you're on to something here. Keep us posted. :)


I think I've invested about as much as I can for now... I'll have some more time next week to play with this... however, I might just get rid of this drive in exchange for something quieter.

I'm really glad to see the interest here though.

Even if i do get rid of the 800JB, i still have plenty of noisy WDAC ~200MB drives to test out with...


It's obvious I have to do something about cooling... i think using a steel plate on bottom and a molded lead plate on top is the best solution. Have to make sure there is good contact for conduction... and have to make sure I get some carpet padding and bolts...

If I add anything to the sandwich I can easily put this contraption in my other tower (mini ATX mobo in a full ATX case leaves plenty of room)...

Thanks for the help and suggestions guys.

-Night
 

Cliptin

Wannabe Storage Freak
Joined
Jan 22, 2002
Messages
1,206
Location
St. Elmo, TN
Website
www.whstrain.us
In my experience, carpet padding is too inconsitent in its construction. I would try for some type of closed cell foam. Maybe neoprene or other foam rubber.
 

Mickey

Learning Storage Performance
Joined
Mar 4, 2003
Messages
139
Location
Left Coast
Foams tend to work best when they're compressed. They don't work very well if they're just floating as a barrier. Home Depot carries a selection of foams. A friend used one for getting his case quieter, but I don't remember the exact kind. I believe a closed-cell would work, like maybe a PVC or urethane if it's available?
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
i'll check the foam situation out tomorrow before class. There is a Lowes and a Home Depot ~1 mile from my house.. I have never looked at their foam selections though.

I was also worried about the consistency of carpet padding, considering that it's made of scraps of different kinds of "junk" foam... I figured if it was ~1" thick and compressed that it really wouldn't matter...
...I think that neopreme might work well..


jtr, Do you think it would be possible to melt the lead to the top steel plate... perhaps make a mold of the HDD top surface and then pour the lead into the mold, then place the steel plate on top of the molten lead... and perhaps drill holes in the steel so that the lead will fill the holes and adhear/bond to the steel.

I'm just trying to be as conservative as possible.. I can get small amounts of lead (I have plenty of bullets and large fishing sinkers I will probably never use)... If all else fails, I can search the local stores for large fishing sinkers.. perhaps I can get $1 per lb... at that rate it'd be ~$8 for 1 plate
 

jtr1962

Storage? I am Storage!
Joined
Jan 25, 2002
Messages
4,184
Location
Flushing, New York
blakerwry said:
jtr, Do you think it would be possible to melt the lead to the top steel plate... perhaps make a mold of the HDD top surface and then pour the lead into the mold, then place the steel plate on top of the molten lead... and perhaps drill holes in the steel so that the lead will fill the holes and adhear/bond to the steel.

That should work, although you'll might need to get the steel plate fairly hot before hand so the lead has a chance to make good contact with the plate before it solidifies. Before you embark on this project though a couple of precautions: 1)Work in a well-ventilated area(lead fumes are not too good for you). 2)Be very, very careful handing the molten material. It is very heavy, and 400°F hotter than boiling water. :eek: 3)Keep any pets out of the area while you're working. 4)Allow for plenty of time to cool before you handle anything.

If you have access to bar solder that would work as well as lead, and melts at about 150° F lower temperature. I'm not sure if the lead in fishing sinkers or bullets is pure lead or a tin-lead allow like solder. I would only use spent bullets for a lead source due to the obviously problems removing the slug from the part containing the gunpowder.

IIRC there is also a bismuth alloy that model railroaders buy that melts under 212°F. I forgot the exact name, but if it's still sold and reasonably priced this might be the best bet. You really only need a fairly small amount of lead/bismuth-mainly to cover the top surface of the drive so that the overlying steel plate makes good contact. A drive is about 4"x5.5", and about 1/4" of lead exactly the size of the drive top should suffice. This is about 6 cubic inches of lead, or roughly 2.5 pounds.

If you can find a cheap online source of surplus lead, please let me know as this is something I'd be interested in as well.

In the foam department, Home Depot has something called Celotex available in 2'x4' sheets, and thicknesses from 1/2" up to 2". It is fairly inexpensive(a 4'x8' of 2" Celotex runs about $20, eveything else is less). I've used it for insulation for my thermoelectric freezer, but it might be just what you need for the sides of the drive. I can barely hear the two noisy cold sink fans when the freezer door is closed, albeit the freezer has 4" of insulation. It's not very compressible, but it can be cut to the exact size you need with a kitchen knife(wear gloves since it pinches and makes a mess when you cut it). Home Depot might also have other types of foam better suited to this project. I tend to think something "rubbery" and fairly dense would work best. I'm not sure what Home Depot has that fits this description other than carpet padding.
 

jtr1962

Storage? I am Storage!
Joined
Jan 25, 2002
Messages
4,184
Location
Flushing, New York
Here's the alloy I was talking about:

http://www.micromark.com/casting.html

Go to the bottom of the page and look at type 160 and type 280. Also a lot of other goodies for making molds here.

The two low-temp alloys run $14.95 for 11.4 oz. They also have something that's almost pure lead(melts at 500°F) at $10.95 for 27 oz. I guess surplus sinkers are just as good if you plan to go with pure lead, amd probably a good deal cheaper as well.
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
oh.. rubber.. that sounds good.... good for noise, bad for heat that is...

looks like I'm going to have to cut things exact on the side pieces... measure twice cut once kinda stuff.

Some sinkers are starting to have less lead .. or lead free.... but you can still find alot of the fully leaded ones around at fishing/outdoor stores or K-mart/Walmart...


I've worked with molten lead before so no worries ... usually melts good outside using a white gas camp stove.
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
oh, any tips on making the mold?

I guess I have to make two... a mold of the HDD top and then a mold of that so I can pour the lead and have a finished product that fits the HDD...

I was thinking of putting saran wrap over the drive and then pressing it into plaster... or possibly paper mache for the 1st mold... will this work well?

My gf is an art student, I'm sure she has experience making molds.
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
jtr1962 said:
In the foam department, Home Depot has something called Celotex available in 2'x4' sheets, and thicknesses from 1/2" up to 2". It is fairly inexpensive(a 4'x8' of 2" Celotex runs about $20, eveything else is less). I've used it for insulation for my thermoelectric freezer, but it might be just what you need for the sides of the drive. I can barely hear the two noisy cold sink fans when the freezer door is closed, albeit the freezer has 4" of insulation. It's not very compressible, but it can be cut to the exact size you need with a kitchen knife(wear gloves since it pinches and makes a mess when you cut it). Home Depot might also have other types of foam better suited to this project. I tend to think something "rubbery" and fairly dense would work best. I'm not sure what Home Depot has that fits this description other than carpet padding.


I found that foam (wasn't labelled celetex, but was large and pink and available in different thicknesses) However, they only had it available in 4' x 8' sheets... so i figured I'd just get some other pink foam that was cheaper...
 

Mickey

Learning Storage Performance
Joined
Mar 4, 2003
Messages
139
Location
Left Coast
I've read of modelers using Plaster of Paris for molds, first coating the original surface with a light layer of petroleum jelly to make it easier to remove later. Just be careful not to plug up any of the breather holes in the cover (if the drive has any) with plaster. Maybe stick a piece of tape over the hole when making the mold?
 

jtr1962

Storage? I am Storage!
Joined
Jan 25, 2002
Messages
4,184
Location
Flushing, New York
blakerwry said:
oh, any tips on making the mold?

I guess I have to make two... a mold of the HDD top and then a mold of that so I can pour the lead and have a finished product that fits the HDD...

I was thinking of putting saran wrap over the drive and then pressing it into plaster... or possibly paper mache for the 1st mold... will this work well?

My gf is an art student, I'm sure she has experience making molds.

I think I would make the initial mold of the HDD top with silicon rubber. Home Depot has it in caulking gun sized tubes for about $3 to $4, and one tube should be plenty. Cover the top of the drive and go down along the sides about 1/2" or so(exact amount not critical). Put on about 1/4" at a time, let it cure a couple of hours(preferably in a well-ventilated room since it stinks like super strong vinegar). A couple of layers(maybe 1/2" to 3/4" thick) should be enough to maintain dimensional stability. Let the whole thing cure about 24 to 48 hours. After that, pour plaster of paris into the mold, being careful to shake out the air bubbles. The plaster should get hard with a few hours tops(usually in about 30 minutes). After that you'll have a perfect plaster of paris model of the HDD top and about 1/2 of the sides as well. You need to make some sort of liquid tight lip extending about 1/4" high above the top of the plaster model. Ideally, it should also be easily removable so you can get multiple uses out of your mold. I'm thinking of something along the lines of 1/16" sheet metal, perhaps held tightly against the plaster mold with clamps. Perhaps put a bit of modeling clay on the part that sits against the plaster for a liquid tight fit. Once this is done(and tested with water to make sure it's liquid tight), you can prepare your steel plate. Warm the plate to the same temperature of the molten lead(or even a little higher). Pour the lead in the mold. Fill it completely, and then put the steel plate on top. Pour in additional lead to fill the holes in the steel plate. Once everything solidifies, every should be nicely bonded together. If the plate and lead detach later on, a very thin layer of epoxy should fix it without impeding the heat flow. I would undercut the holes a bit on the side away from the lead to aid retention(same as a dentist does when filling a cavity).

I'm sure your gf can offer many helpful suggestions as well.
 

jtr1962

Storage? I am Storage!
Joined
Jan 25, 2002
Messages
4,184
Location
Flushing, New York
The heat's no big deal once it's cured(i.e. once all the water comes out). This takes about 24 to 48 hours. We're only talking ~600°F here. I've used plaster of paris molds multiple times for lead castings. I've even had luck with one-use cardboard molds, although these sometimes ignite if I'm not careful. :eek: Silicon rubber can take up to about 500°F, so that might be borderline suitable here. I've never really tested it. I don't know what happens when silicon rubber gets too hot(does it melt, soften gradually, just fall apart?).
 

Mickey

Learning Storage Performance
Joined
Mar 4, 2003
Messages
139
Location
Left Coast
If it's like silicone gasketing, it should break down once it gets too hot. I had to bake some in an oven to cure it and couldn't use the regular one in the lab because it didn't get hot enough (needed close to 200 C). I made the mistake of fishing the parts out w/o mitts before it had completely cooled. :eek: Dumb, dumb, move.
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
jtr1962 said:
blakerwry said:
oh, any tips on making the mold?

I guess I have to make two... a mold of the HDD top and then a mold of that so I can pour the lead and have a finished product that fits the HDD...

I was thinking of putting saran wrap over the drive and then pressing it into plaster... or possibly paper mache for the 1st mold... will this work well?

My gf is an art student, I'm sure she has experience making molds.

I think I would make the initial mold of the HDD top with silicon rubber. Home Depot has it in caulking gun sized tubes for about $3 to $4, and one tube should be plenty. Cover the top of the drive and go down along the sides about 1/2" or so(exact amount not critical). Put on about 1/4" at a time, let it cure a couple of hours(preferably in a well-ventilated room since it stinks like super strong vinegar). A couple of layers(maybe 1/2" to 3/4" thick) should be enough to maintain dimensional stability. Let the whole thing cure about 24 to 48 hours. After that, pour plaster of paris into the mold, being careful to shake out the air bubbles. The plaster should get hard with a few hours tops(usually in about 30 minutes). After that you'll have a perfect plaster of paris model of the HDD top and about 1/2 of the sides as well. You need to make some sort of liquid tight lip extending about 1/4" high above the top of the plaster model. Ideally, it should also be easily removable so you can get multiple uses out of your mold. I'm thinking of something along the lines of 1/16" sheet metal, perhaps held tightly against the plaster mold with clamps. Perhaps put a bit of modeling clay on the part that sits against the plaster for a liquid tight fit. Once this is done(and tested with water to make sure it's liquid tight), you can prepare your steel plate. Warm the plate to the same temperature of the molten lead(or even a little higher). Pour the lead in the mold. Fill it completely, and then put the steel plate on top. Pour in additional lead to fill the holes in the steel plate. Once everything solidifies, every should be nicely bonded together. If the plate and lead detach later on, a very thin layer of epoxy should fix it without impeding the heat flow. I would undercut the holes a bit on the side away from the lead to aid retention(same as a dentist does when filling a cavity).

I'm sure your gf can offer many helpful suggestions as well.


The silicon is a good idea... I was thinking of wax or clay... but I bet I have some silicon caulk in the garage

Mickey, dont worry, i'll be sure to cover the entire drive in saran wrap before getting it near anything...
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
Mickey said:
If it's like silicone gasketing, it should break down once it gets too hot. I had to bake some in an oven to cure it and couldn't use the regular one in the lab because it didn't get hot enough (needed close to 200 C). I made the mistake of fishing the parts out w/o mitts before it had completely cooled. :eek: Dumb, dumb, move.

Mickey, the reason for the silicon is that I need to make 2 molds...

1) Mold 1 is the only mold that touches the HDD.. it gets my first shape of the HDD... if I poured the lead into this, the result would be a copy of the HDD surface... since I want the lead to be a mirror or reflextion of the HDD shape I have to create a mold of the mold, so to speak.

2) Mold 2 looks just like the shape of the HDD, however unlike the HDD it can take the extreme temperatures of molten lead... I pour the lead into mold 2 and the result will be a mirror/reflection of the shape of the HDD surface, making the lead fit together with the HDD top like 2 pieces of a puzzle
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
mold 1 will be a soft, easy to manage mold... wax, clay, silicon, etc...

mold 2 will be a mold that can take the heat of molten metal... plaster seems like the best bet.
 

Mickey

Learning Storage Performance
Joined
Mar 4, 2003
Messages
139
Location
Left Coast
D'oh! :oops: I kept thinking you'd only need one mold. You're right; you'd just end up with a pretty fancy paperweight that looked just like a drive if you only had one mold.

You know, this brings up an interesting idea. How many people do you think would be interested in being able to buy off-the-shelf parts that would fit specific drives, for cooling/noise muffling use?
 

blakerwry

Storage? I am Storage!
Joined
Oct 12, 2002
Messages
4,203
Location
Kansas City, USA
Website
justblake.com
Mickey said:
D'oh! :oops: I kept thinking you'd only need one mold. You're right; you'd just end up with a pretty fancy paperweight that looked just like a drive if you only had one mold.

You know, this brings up an interesting idea. How many people do you think would be interested in being able to buy off-the-shelf parts that would fit specific drives, for cooling/noise muffling use?

my guess is just us enthusiasts... there are retail products that do what I'm doing... and I'm probably spending just as much as a cheap unit for something that is much less practical (most retail units mount in the 5 1/2" drive bays) My only comfort is that when I'm done this thing might actually cool my drive while helping me keep my sanity...

The retail units are limited to either 5400 or 7200rpm drives.. the 7200 rpm boxes seem to go from $50-$80... OUCH! and it seems as though these boxes push the drives to their thermal limits.

Really, i wish i had gotten a cudda... my 1200bb is still very quiet... but seems to have become as loud as my ATA IV in idle noise... it's just this pissant of an 800JB that requires my action.
 
Top