The equipment used to measure the CFM and Sound levels of Fans will cost many times more than a pc , so drop the idea of even attempting those.:O
RE: Bearing types.
it would be best if you "actually" buy a sleeve / BB type fan (even damaged ones will do. break them open and you would learn more than what we can put in words here).
hyeah:
for e.g. a few months back i had purchased one artic cooling cpu h/s from a member here. the fan was damaged. (which the member had mentioned beforehand).
after receiving the package, opened the fan and found the cause of the problem. (broken ceramic shaft, artic cooler fans have ceramic hafts unlike the steel ones of other brand fans)
(ps: ceramic's are way tougher than steel. i tried my level best to grind it to a even surface but no luck.)
anyways to find a suitable fan blade assembly for it i must have bought and opened the following
1 panaflo 80 mm, original sunon 80 mm, 1 original intel p4 cpu fan, 1 intel p3 fan.
opened them all up and learned a lot about there structure.
(actually all these fans have a small 3/4 pin ic which regulates and controls the the motion of fans. the 4 pin IC ones have "Hall effect" sensors , which i think detect motion and hence we get RPM sensing from these.)
Sleeve bearing is sort of a misnomer. it does not have a bearing as we understand. it has a brass cylinder about 1/2 inch in lenght with a hole in the centre , in which the shaft of the fan blade assembly is inserted and "locked" with a plastic washer on the otherside. This brass cylinder is the sleeve bearing.
The ball bearing types have , a tiny ball bearing in which the shaft of the fan blade assemly is inserted. This ball bearing is the type which we are "normally" accustomed too (in mobikes, cars etc.....)
As i said earlier it is very difficult to explain it in words best would be if you actually open a few fans.
Expirience is a great teacher !!
