On Fri, 25 Aug 2023 08:48:53 +0100
The Natural Philosopher <tnp@invalid.invalid> wrote:

As do clock and watch repair people.

They generally use a really nice synthetic oil that's certain not
to damage brass.

--
Steve O'Hara-Smith
Odds and Ends at http://www.sohara.org/
Host: Beautiful Theory meet Inconvenient Fact
Obit: Beautiful Theory died today of factual inconsistency

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On Wed, 23 Aug 2023 17:33:31 +0100, in
<e40f86d85a.DaveMeUK@BeagleBoard-xM>, David Higton
<dave@davehigton.me.uk> wrote:

In message <64e53aed@news.ausics.net>
not@telling.you.invalid (Computer Nerd Kev) wrote:

Brian Gregory <void-invalid-dead-dontuse@email.invalid> wrote:

You can just use a series resistor to slow the fan while still powering
it from 5V. Exp0eriment with the value of resistor until you get the
right speed.

That's a much better option than stressing the voltage regulator on the Pi. >> A 2V zener diode could also be used in series to avoid needing to
experiment with the resistor value if 3v is considered roughly optimal. Or >> 2-3 normal silicon diodes in series.

I too would recommend any of those solutions.

Running a fan from the 3.3V line might work, and clearly it does for
some people's cases; but it isn't possible to generalise from one or
two cases. The 3.3V line may or may not have adequate spare capacity
for a particular fan.

I imagine a fan works fine off the 3.3v line if the only things
drawing power are the Pi and a fan, but for those who also have one or
more hats I wouldn't dream of powering a fan off the 3.3v line. It's
too easy to add a resistor or diodes, as mentioned above, and power
from the 5v supply.

Sewing machine oil can be either natural, synthetic or petrochemical.
I'd use synthetic (silicone), but not the other two, esp not natural.
Natural oil ages, oxidizes and evaporates over time. Good luck if the
can the oil comes in specifies what's what.

I'd also use a fan with ball bearings, not sleeve bearings.
--
Jim H

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On 2023-08-25, The Natural Philosopher <tnp@invalid.invalid> wrote:

It seems that 5V fans are typically 300mA or less.

On 3v Id expect them to be around 150mA. That is not a huge amount to
load a 3V supply with.

I've only actually taken measurements a couple of times previously
but in my experience BLDC fans work to a first approximation as a
constant current sink. E.g. if a fan draws 200mA at 12V it'll draw
near as dammit 200mA on 5, 6, or 7V.

They are also incredibly cheap - $4 or less. Oil to fix a flagging bad
one is probably more expensive

Careful though, those cheap fans may work out very expensive
especially when the hassle as well as expense of premature further
replacement is factored in. It generally pays to get something
mid-market (or nearer the premium end of the computer market) with
a longer expected service life otherwise you are just replacing
junk with junk.

On the other hand, you'd probably find it difficult to justify true
premium replacements - e.g. you could easily multiply that budget
by ten for certain Papst ranges. Great fans sure, but several tens
of dollars each probably isn't a justifed investment.

--
Andrew Smallshaw
andrews@sdf.org

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On 2023-08-24, Grant Weasner <nospam.Grant.Weasner@f317.n229.z1.fidonet.org> wrote:

The Natural Philosopher wrote to bbsing <=-

On 23/08/2023 13:02, Grant Weasner wrote:

Charlie Gibbs wrote to The Natural Philosopher <=-

CG> On 2023-08-23, The Natural Philosopher <tnp@invalid.invalid> wrote:

> On 22/08/2023 15:16, Jan Panteltje wrote:
>
>> I had a noisy 5 V fan in the Pi4 4 GB, I took the fan apart,
>> took the rotor out and greased the shaft with some vaseline.
>> That was about 2 years ago.
>> It has been quiet ever since, works perfectly, 24/7.
>
> you shouldn't use grease on small electric motors.
> Light sewing machine oil is best.

CG> Yup. I've revived a lot of fans with a few drops of 3-in-1 oil.

Yeah don't use grease ... grease was just a poor word choice, 3-in-1 oil is what I used, but not always easy to get, depending where you live.

'3 in 1' is one brand, 'sewing machine oil' is another good term to search for. or 'light machine oil'. That last got me the most results on Amazon.

The sort of stuff model train people use.

I didn't know '3 in 1' was a brand. So next time I need something good, I'll know how to better search for it online.

Thanks The Natural Philosopher

___ MultiMail/Linux v0.49

https://duckduckgo.com/?q=3-in-1+oil&hps=1&start=1&ia=web

It has been a brand in the US for at least 55-60 years. I have a
metal can of it in my box of misc. hobby chemicals (glues, oils,
etc.) that I think my father had when I was in grade school. The
paint is all worn out, but the oil seems to have maintained at
least a decent character.

HTH

--
Robert Riches
spamtrap42@jacob21819.net
(Yes, that is one of my email addresses.)

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On 26 Aug 2023 02:30:35 GMT
Robert Riches <spamtrap42@jacob21819.net> wrote:

3-in-1

It has been a brand in the US for at least 55-60 years.

Also in the UK.

--
Steve O'Hara-Smith
Odds and Ends at http://www.sohara.org/
Host: Beautiful Theory meet Inconvenient Fact
Obit: Beautiful Theory died today of factual inconsistency

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On 26/08/2023 07:49, Ahem A Rivet's Shot wrote:

On 26 Aug 2023 02:30:35 GMT
Robert Riches <spamtrap42@jacob21819.net> wrote:

3-in-1

It has been a brand in the US for at least 55-60 years.

Also in the UK.

"3-in-One Oil is a general-purpose lubricating oil sold for household
and do-it-yourself use. It was originally formulated in 1894 for use on bicycles, and remains a popular lubricant for their chains. Its name,
given by inventor George W. Cole of New Jersey in 1894, reflects the
product's triple ability to "clean, lubricate and protect".

The product changed ownership many times throughout the 20th century and
was bought by its current owners, the WD-40 Company, in 1995."

--
“Some people like to travel by train because it combines the slowness of
a car with the cramped public exposure of 
an airplane.”

Dennis Miller

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On Sat, 26 Aug 2023 10:11:43 +0100
The Natural Philosopher <tnp@invalid.invalid> wrote:

It was originally formulated in 1894 for use on
bicycles, and remains a popular lubricant for their chains.

That's what I used it for mainly - it kept my bikes running smoothly for a couple of decades.

--
Steve O'Hara-Smith
Odds and Ends at http://www.sohara.org/
Host: Beautiful Theory meet Inconvenient Fact
Obit: Beautiful Theory died today of factual inconsistency

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