Clamping force for a P4 WB

Tuhran · 05-04-2003, 07:42 PM

Anybody know how many pounds of force I need to mount a WB on a P4? (yes, I've searched; almost all of the info is for AMD, understandably).
I have NeoMoses excellent guide to applying specific clamping pressures with springs, but need the psi numbers for P4's.
My understanding is that some considerable amount of pressure must be applied for proper deformation of the IHS, so I feel the numbers are important.
Thanks...

Cathar · 05-04-2003, 08:57 PM

ftp://download.intel.com/design/Pent...s/29864308.pdf

Page 34.

100lbs static

200lbs dynamic (ie. extra force applied through moving the heatsink about momentarily - such as dropping the computer on the ground)

Tuhran · 05-04-2003, 10:35 PM

Thank you very much, Cathar.
I posted this question on the OC forums but received no response. I Googled and found some Intel data sheets, but not that one.
As part of my search here I came across threads with information from BillA, who gave the 100 lbf value, and Morphling1, who gave a value of 70 lbf.
As I certainly consider both of these gentlemen to be knowledgable sources, I did not know what to do about the discrepancy. Granted, the 100 lbf is a maximum, so 70 may be a good practical value.

My remaining issue is how to achieve this pressure. Some recommend that to get this amount of force, I should dispense with springs altogether. If I use NeoMoses' method (since I'm mounting his block using his 6-32 threaded rods and his 4 lb springs), I would need to compress the springs 6.25 inches -- pretty tricky on a 3.5 inch rod.

Any suggestions? Try to find 12 lb/in. springs? Or lose the springs and hand-tighten everything down as hard as I can?

I'm at a stopping point in assembling my system until I can comfortably resolve this. I've PM'ed Neo about this and will wait for his recommendation since it's his hardware. I very much appreciate your response and would be open to any suggestions that you and the other members of this forum might have to offer.

Thanks.

Edit: BillA responded over at OC while I was writing this message, again giving the 100 lbf figure, so I feel pretty good about that. Still just need to figure out how to apply it.

Cathar · 05-04-2003, 11:52 PM

Hmmm, for my block I had 5kg/cm tensioned springs made up with a total compression travel of 18mm per spring.

5 x 4 x 1.8 = 36kg, or around 80lbs of pressure, which was adequate for Intel applications.

Problem is that I'm pretty much all out of springs, otherwise I would have offered to send you some.

Sorry to be of no help to you.

Tuhran · 05-05-2003, 10:00 AM

On the contrary, I appreciate the response and the kind offer of the springs.
As it turns out, I heard from Neo, and the actual specs on the springs he shipped with my block are 19 lb/in., which is plenty to allow good compression on a P4. (The 4 lb/in. value in his method description was used to keep the math simple).
Again, thanks for your attention to my problem.

hara · 05-05-2003, 10:23 AM

I got springs out of pegs (used to hang clothes to dry them). They are a bit harder than the Maze3's and thought they were adequate. You could use hard springs and compress them a little, search around.

Tuhran · 05-06-2003, 11:15 AM

Thanks for the idea, hara, but the ones in NeoMoses' kit turned out to work just fine.
Doing it by the numbers, I was able to take the springs to nearly full compression (by hand-tightening, anyway), with a resulting lbf of just over 60.
I could break out the pliers at this point, but the springs do look very compressed, and I don't want to make a washer out of them and have an exponential force effect.

Besides, my MB is starting to warp.

Thanks for everyone's advice. Off to measure and cut tubing!

05-04-2003, 07:42 PM	#1
Tuhran Cooling Neophyte Join Date: Apr 2003 Location: USA Posts: 5	Clamping force for a P4 WB Anybody know how many pounds of force I need to mount a WB on a P4? (yes, I've searched; almost all of the info is for AMD, understandably). I have NeoMoses excellent guide to applying specific clamping pressures with springs, but need the psi numbers for P4's. My understanding is that some considerable amount of pressure must be applied for proper deformation of the IHS, so I feel the numbers are important. Thanks...

05-04-2003, 10:35 PM	#3
Tuhran Cooling Neophyte Join Date: Apr 2003 Location: USA Posts: 5	Thank you very much, Cathar. I posted this question on the OC forums but received no response. I Googled and found some Intel data sheets, but not that one. As part of my search here I came across threads with information from BillA, who gave the 100 lbf value, and Morphling1, who gave a value of 70 lbf. As I certainly consider both of these gentlemen to be knowledgable sources, I did not know what to do about the discrepancy. Granted, the 100 lbf is a maximum, so 70 may be a good practical value. My remaining issue is how to achieve this pressure. Some recommend that to get this amount of force, I should dispense with springs altogether. If I use NeoMoses' method (since I'm mounting his block using his 6-32 threaded rods and his 4 lb springs), I would need to compress the springs 6.25 inches -- pretty tricky on a 3.5 inch rod. Any suggestions? Try to find 12 lb/in. springs? Or lose the springs and hand-tighten everything down as hard as I can? I'm at a stopping point in assembling my system until I can comfortably resolve this. I've PM'ed Neo about this and will wait for his recommendation since it's his hardware. I very much appreciate your response and would be open to any suggestions that you and the other members of this forum might have to offer. Thanks. Edit: BillA responded over at OC while I was writing this message, again giving the 100 lbf figure, so I feel pretty good about that. Still just need to figure out how to apply it. Last edited by Tuhran; 05-04-2003 at 10:45 PM.

05-05-2003, 10:23 AM	#6
hara Cooling Savant Join Date: Oct 2002 Location: Malta, Mediterranean Posts: 662	I got springs out of pegs (used to hang clothes to dry them). They are a bit harder than the Maze3's and thought they were adequate. You could use hard springs and compress them a little, search around. __________________ - Every great HD crash day is the day before back-up day. - My Past System - "Better to reign in Hell than serve in Heaven." - Milton, Paradise Lost. - FMZ

05-04-2003, 08:57 PM	#2
Cathar Thermophile Join Date: Sep 2002 Location: Melbourne, Australia Posts: 2,538	ftp://download.intel.com/design/Pent...s/29864308.pdf Page 34. 100lbs static 200lbs dynamic (ie. extra force applied through moving the heatsink about momentarily - such as dropping the computer on the ground)

05-04-2003, 11:52 PM	#4
Cathar Thermophile Join Date: Sep 2002 Location: Melbourne, Australia Posts: 2,538	Hmmm, for my block I had 5kg/cm tensioned springs made up with a total compression travel of 18mm per spring. 5 x 4 x 1.8 = 36kg, or around 80lbs of pressure, which was adequate for Intel applications. Problem is that I'm pretty much all out of springs, otherwise I would have offered to send you some. Sorry to be of no help to you.

05-05-2003, 10:00 AM	#5
Tuhran Cooling Neophyte Join Date: Apr 2003 Location: USA Posts: 5	On the contrary, I appreciate the response and the kind offer of the springs. As it turns out, I heard from Neo, and the actual specs on the springs he shipped with my block are 19 lb/in., which is plenty to allow good compression on a P4. (The 4 lb/in. value in his method description was used to keep the math simple). Again, thanks for your attention to my problem.

05-06-2003, 11:15 AM	#7
Tuhran Cooling Neophyte Join Date: Apr 2003 Location: USA Posts: 5	Thanks for the idea, hara, but the ones in NeoMoses' kit turned out to work just fine. Doing it by the numbers, I was able to take the springs to nearly full compression (by hand-tightening, anyway), with a resulting lbf of just over 60. I could break out the pliers at this point, but the springs do look very compressed, and I don't want to make a washer out of them and have an exponential force effect. Besides, my MB is starting to warp. Thanks for everyone's advice. Off to measure and cut tubing!

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