Fan bearing lubricant was Re: WD-40 (again)

[Noel Chiappa]

{Multiple replies packaged together to minimize list traffic...}


    > From: Jon Elson

    > If you open one of these up, make sure to oil the cotton packing to
    > supply oil gradually to the bearing.

I don't see any sign of a cotton packing around it (but maybe it's just
sealed away where I can't see it). There is a gasket/washer of some sort of
packing material / felting at one end, but I suspect that's for dust
interception, not as an oil resevoir, as in the fan's normal operating
orientation, it's on the bottom.

Speaking of orientation, though: these fans, like most PDP-11 fans, send air
downwards. I was thinking of flipping them, to send the heat upwards (its
'natural' direction), but after pondering a bit, I'm not sure this is a good
idea: the air-flow on the intake side is diffuse, whereas on the output, it's
a concentrated, directed blast - better for cooling boards, etc.


    > From: Chuck Guzis 

    > I did some research among the antique fan collectors on the web.

Thanks very much for taking the time to do that; my only concern is to wonder
if their experience is applicable, since these things are turning an order of
magnitude faster than old household fans.

    > Here's what's been recommended, in no particular order:
    > ..
    > 3-in-1 Electric Motor Oil (SAE 20)

That's what I've been working with so far, but I was wondering if it would
last without going gummy. If they're happy with it for the long term, that
sounds like it would be good for this too.


    > From: Corey Cohen

    > I like to use a product called SuperLube that I get at the gun store.
    > It's synthetic and I find it doesn't like to pickup dust

Thanks for the tip; I'll see if I can find any here. Oddly enough, I had
found something called Hoppe's Lubricating Oil on my shelf - it's for
firearms and fishing reels, and explicitly claims that it "will not gum [or]
harden", which also sounds like it might similar to the above, and just
what's called for.

I had seen reference online to people using synthetic automatic transmission
fluid, but the stuff I looked at claimed to "stop leaks", which makes it
sounds like it contains some agent which hardens (or at least coagulates) when
exposed to air (although I would assume there was some exposure to air in the
transmission?), which is definitely not what is wanted!

	Noel