View Full Version : Ball vs. Sleeve bearing fans - fan plug

04-03-2003, 10:22 AM
I just wanted to confirm that ball bearing fans are much better than sleeve ones, i've read that these end up being stucked hard (i've had this experience lots of times, but never looked for the bearing type) so i can be sure to not buy sleeve ones anymore.

As a side note, i have a ball cpu fan that just doesn't have the plug (it's been cut off), it's a socket 370 class fan with the three wires (red, black and yellow). I know the red's for 12v, the black for ground and yellow is for the speed sensor.
But i'll be using it on a socket 7 pentium machine, so i'll wire and weld it directly to a PSU plug rather that to motherboard.
So my question is: should i weld also the sensor wire to the 5v lead or it's not necessary? Or contrary, if i do it will it do any harm? Also, does it matter which of the two grounds i use? I guess i should use he one next to the red 12v lead right?

Thank you!

04-03-2003, 12:36 PM
Connect the Yellow wire to the Mother Board fan speed connector

04-03-2003, 12:45 PM
Yes, use the ground next to the 12v yellow on the molex plug.

No, don't attach the sensor lead to 5v. If the motherboard doesn't have a fan speed connector to use (as Rick suggests) then leave that fan wire unattached.

04-03-2003, 12:47 PM
This old mobo doesn't have any fan connector Rick, that's why i'll weld it to a PSU cable. And that's why i'm wondering what to do with the yellow cable, if i should weld it to the 5v lead or just leave it disconnected.
To explain further i'd just like to replace the actual Socket 7 fan in use in my older machine with this one that is bigger and seems a bit more powerful (thus allowing me to overclock it a bit and draw all the juice it has left out of it :) , but that's another story), but i need to adapt it so it can be connected to the PSU rather than with a normal Socket 370 on-board plug.

04-03-2003, 12:56 PM
Well sleddog, you just came in while i was posting.
That nearly answers all, just one more thing:

Yes, use the ground next to the 12v yellow on the molex plug.

Isn't it the 12v one the red? Sorry if i'm wrong!

About sleeve vs. ball, i've already read in a couple of pages that sleeve is the worst. I'd mistakenly thought ball bearing was.

Thanks to both!

04-03-2003, 05:20 PM
Generally ball bearing is the way to go for MTBF and I think even for noise....

04-03-2003, 05:42 PM
Sleeve fans are generally quieter, ball bearing fans generally last longer, about 50 000 hours as opposed to 30 000 for sleeve.

Coolermaster has some new patented "rifle bearing" fans which are as quiet as sleeve fans and as durable as ball fans.

On the 4 pin molex from your PSU, the yellow wire is the 12V, the red is the 5V.

On the 3 pin fan connector, the red wire is the voltage wire (12V)

The black wires on both are COM (ground)

04-03-2003, 05:59 PM
ok, so i should connect it as this (correct me if i'm wrong):

PSU cable************************Fan
Yellow 12v-----------------------Red 12v
Black Ground---------------------Black
Black Ground___________________Yellow Sensor (leave unconnected)
Red 5v
(where - means connected and _ unconnected. Spaces had been trimmed so i had to use _, hope you understand)

Also, does it really matter which of the two grounds i use? (just for learning, as you can see i'm not so knowledgeable on electricity :( )

Thank you all

04-03-2003, 06:03 PM
Like sleddog said

Yes, use the ground next to the 12v yellow on the molex plug.

04-22-2003, 07:30 AM
And you’re going to solder it not weld it.

Solder is an alloy of tin and lead used as an electrically conductive “adhesive”.
The solder adheres to the two pieces of copper and acts as a conducting bridge.
The adhesive solder is very convenient because it melts at relatively low temperature and is hard and strong enough for its purpose.

With welding [usually of steel (which is Iron with the % Carbon content reduced to a very specific value)] the Joining material [if any is used] is practically identical [steel also] to the items being joined which are also all identical.
The finished result consists of one material throughout [with identical ingredients, particularly Carbon content] with the crystal structure of the steel manipulated by heat treatment to produce as homogeneous a structure as possible.
This is a much more difficult process and normally beyond the capability of the hobbyist.

Will this information be thought interesting or irrelevant I wonder?

04-22-2003, 08:27 AM
Interesting enough for me to lookup the definition of "weld" :)

http://www.infoplease.lycos.com/ipd/A0734140.html states that "weld" means:

1. to unite or fuse (as pieces of metal) by hammering, compressing, or the like, esp. after rendering soft or pasty by heat, and sometimes with the addition of fusible material like or unlike the pieces to be united. (Emphasis added).

So the difference between soldering and welding would seem not to be that the joining material is the same as the original material, but rather that the materials to be joined are "rendered soft or pasty by heat" prior to the joining. (?)

04-22-2003, 12:58 PM
Thats the way the old blacksmiths did it in the 1800's and before.
It was like joining two bits of toffee.
You made the metal cherry red and soft in the forge and hammered them together so they fused to become one.
It's still possible to do it that way but it's an antique method and you'd need to search long and hard to find anyone using it.
The closest modern method is "Friction Welding" where the two pieces are forced into contact and spun so that the friction converts work input to heat and when the metal is hot enough and the force great enough, the two fuse [or weld] together.
Nowadays most welding is done with filler rods coated with flux using electricity to melt the rod and deposit the metal in a specially prepared, precisely shaped and dimensioned gap with the metal each side pre-heated to prevent rapid cooling.
Rapid cooling creates brittle crystal structures in the weld material which makes it prone to shattering rather than deforming elastically and safely.

I've never come across an example of unlike filler material being used and cannot think of an example.
Brazing uses brass as a filler or adhesive but I've never thought of that as welding.
I was taught to consider using epoxy resin adhesive since it has a strength of 3 Tons per square inch and there's no high temperatures involved in the process. I actually used it to seal Aluminium plugs inside each end of a two inch tube to pressurise it and measure the resulting strains using strain guages attached to the surface.
It worked well.

david eaton
04-22-2003, 03:43 PM
Sylvander, You don't actually have to look very far to find someone who uses forge welding. I have, quite recently! And I kid you not, it is very hard, hot work.


04-22-2003, 04:52 PM
I can imagine David, but tell me more.
What are the circumstances?
Why did you choose to use this method?
How come you have the necessary equipment?
Did you use a forge and anvil and hammer etc?
Give the details of this fascinating and ancient method.
What do you consider to be the advantages over modern methods?

Alejandro is probably finished with this thread anyway, but if not we can talk amongst ourselves until he returns.

04-22-2003, 09:37 PM
Originally posted by david eaton
You don't actually have to look very far to find someone who uses forge welding.
David Correct. Some ornamental ironwork and sword making is still done the old fashioned way. A search using Google was not "long and hard."

04-22-2003, 11:59 PM
Yep, most of the smiths around here are of the variety that make ornamental work..so they do most of their work the "old fashioned" way.

So do the Amish in the neighboring states of PA and Ohio.

04-23-2003, 06:29 AM
Well, I picked up my yellow pages and phoned a Blacksmith at random and asked if he still used forge welding and he became rather cagey.
“It CAN still be done”, he says. “Yes, but is it; do you?”
“Well some company’s still do it.”
“Do you still do it?”
“Well, on the odd occasion, under special circumstances where the original job was done that way, we can still use FIRE WELDING.”
“It’s not the best method for the mild steels of the present time.”
“In times past things were made using Wrought Iron and that is more suitable for fire welding.”
“If you try to fire weld mild steel it’s not so easy.”
“You’ve got to coat the workpiece with lots of paste [flux].”
“You get scale on the surface.”

My original point was that you don’t weld electrical contacts together.
You use a sort of metalic adhesive [an alloy of tin and lead that is electrically conductive] to attach one [copper] conductor to another.
If solder had the property of not adhering to copper then it would not work.

A flux must be used to clean the copper surfaces or it will not adhere.
When the cohesive forces within the flux exceed the adhesive forces to the copper the flux tends to form little spheres [unless it's adhering to the soldering iron or something else].
This is another interesting topic: cohesion versus adhesion.

Solder has the advantage of melting at relatively low temperature and can be remelted to un-attach the conductors.

Can you see how welding and soldering differ?

david eaton
04-23-2003, 03:09 PM
The reason I did some forge welding was really only "showing off"!!

I was for several years the chief engineer at a local steam museum, and we had a complete blacksmith's shop on site, which we used for demonstrations to visitors, and to forge the odd bracket etc.

I was talking to the self-taught smith on site, and he said that he had never been able to do forge welding. He was using modern mild steel, which needs to be at the burning point to weld. I said I hadn't done any for years, but I would show him how I did it.

Then I cheated, and chose a couple of bits of wrought iron from an old fence! Welded beautifully at bright red. I have about five generations of blacksmiths in my family tree so perhaps there is something in heredity!


04-23-2003, 05:04 PM
I did Blacksmith classes for a year when I was 15 back in the sixties but we only did very basic work, never did anything so advanced as forge welding.

That’s a bit naughty though.
The poor guy is probably trying over and over to do it with mild steel and failing.

04-23-2003, 08:38 PM
Then I cheated, and chose a couple of bits of wrought iron from an old fence! Welded beautifully at bright red. I have about five generations of blacksmiths in my family tree ...

Mean, cruel, nasty.....hehe, I love it.