Extend life of worn-out cooling fan bearings by lubricating

[geert_2 557]

Hello all. Here is a tip that can extend the life of small fans, such as those on the UM print head or on old computer CPUs. When these fans start to get noisy, which means that the bearing is worn-out or running dry, try lubricating them instead of throwing them away.

The bearings are accessible under the label on the fan. You can partially remove the label from the fan, but don't take the rest of the fan apart.

I have used two methods:

1. Partially remove the label from the fan, and add a drop of oil directly on the bearing. Put the label back. Advantage: easy method, and you can see what you are doing. Disadvantages: you have to remove the fan from the print head, oil can leak away easier, and readjusting the label may be difficult or impossible, if contaminated with oil. You can also do without label, but then the bearing can contain less oil, before spilling it around.

2. Do not remove the label at all, but with a sharp point, gently poke a tiny hole in the label near the top of the bearing. You can feel where the bearing is by gently pushing on the label before poking through it. Get an injection syringe and needle (ask in a pharmacy), cut off the sharp needle-tip with a nylon disk cutter on a Dremel, and sand its edges until rounded, so you won't hurt yourself. Fill the syringe with oil, and inject a drop through the hole you just poked in the bearing's label. Advantages: the oil is better contained, and you have no problem readjusting the label. You can do this while the little fan on the back of the UM2-head is still mounted in the system, without disassembling. Just don't inject too much oil. Disadvantages: you can't see inside the label, so you are not sure what you are doing, unless you have opened enough fans in the past, so you know them well. And you can't see how much oil you are injecting.

And now the bearings will run smoothly again for some time. How long depends on various factors.

If you waited too long before lubricating, and the fan is slowing down, the bearing will be worn out too much, and the oil will not last very long, maybe a few days or weeks.

If you do this too soon, and you use incompatible oil, or oil that is inferior to the original oil, you may shorten its life. Incompatible oils might become jelly, and no longer lubricate.

I usually lubricate the bearings when the fan or motor starts to get noisy, but long before it begins to slow down. Then this method is usually good for months.

I have used various fine lubricating oils in the past, such as those for model railroad trains, or for bike bearings and chains, and they all seem to work. At this moment I am using an oil for hydraulic test machines and industrial equipment (BP Energol HLP-S 46). Why? Simply because I have a lot surplus from my test machine... I don't know if it is the best oil for this, but it works. And it does not dry out easily (contrary to some other fine oils), so it lasts long.

At least, it could help in case of emergency, if a fan slows down too much due to wear, and you have no replacement immediately available.

Of course, most of you will already have tried this. But some people may not have thought of it yet, so I thought I would just write it down.