On Tue, 18 Jul 2017 10:28:21 -0700, John Robertson <
sp...@flippers.com>
wrote:
>Hi Jeff,
Not high enough.
>Hate to ask (I can see an oil thread looming (sorry)) but what do you
>recommend for oil? I figure a non-detergent 20w oil is good for most
>small mechanical machines lube points, and have tried synthetic oils on
>tiny motors (CD spin motors) with good success. I have to assume there
>is no ideal oil though.
First, a little background and drivel. My father owned a women's wear
(mostly lingerie) factory in Smog Angeles. I got plenty of experience
building, fixing, and adjusting industrial sewing machines and making
attachments. Then, I discovered electronics and largely abandoned
sewing machinery. Lately, I've become rather bored with electronics,
computing, and some of my other activities, and though it might be
interesting to do sewing machine repairs on the side. Big mistake,
but I won't bore you with the problems I created. Meanwhile, I've
collected a small collection of older machines, most of which are
being slowly repaired and sold. Not the best credentials but perhaps
good enough for the basics.
Oil for sewing machines, microscopes, guns, and clocks all have two
requirements that must be met. The oil should not evaporate and
should remain at a constant viscosity over the working temperature
range. That's because these devices rely on residual friction of the
lubricant to control the movement of mating parts. Changes in this
friction will result in undesirable changes in timing and adjustment.
Big industrial sewing machines solve the gum and evaporation problems
by using an oil sump and splash lubrication. It won't turn to gum
because additional oil just washes away the gum. It can evaporate,
but with so much oil in the sump, it's unlikely to ever be run without
oil. Too bad it makes such a big mess. I've also never seen an oil
sump on a home type sewing machine.
Another way is to do it like an automobile engine, and pump oil down
an oil gallery into mating surfaces via holes in the bushings. That
works, but is too complicated, expensive, and messy for a home
machine.
So, what's left? Felt oil pads is what most home machine use. That
works, but requires much better oil than the previous 2 methods of
lubrication. That is why you don't use engine oil, WD40, penetrating
oil, or home brew in a sewing machine. None of these oils are
constant viscosity or even close to the viscosity specified by the
sewing machine design. Even clock oil is marginal, because clocks are
not designed to handle the rotational speeds and reciprocating
pounding found in sewing machines.
So, what works? Ummm... sewing machine oil perhaps? They're largely
all the same stuff different in viscosity for different manufacturers.
<
https://www.mobil.com/en/industrial/lubricants/product-series/mobil-velocite-sm-series>
Ok, so you're not going to buy it by the gallon, but the specs are the
same as what you get with retail overpriced sewing machine oil.
>Have you a preferred link for an online page that gives a good
>description of oils and what jobs they are best for?
No, but I'll see if I can find something. I doubt if anyone can get
all the various types of lubricants on a single web page. In general,
the lube selection pages of the major oil companies do better than the
specialty oil formulation pages. For example start here:
<
https://www.mobil.com/en/industrial>
I'll see if I can find some more links later.
We had this discussion in some newsgroup recently. The consensus
among those that tried acetone and ATF as a penetrating oil varied
radically from it works great, to it sucks. Several people discovered
that there are different types of ATF, one of which wouldn't even mix
properly with acetone. I'll see if I can find the thread.
Please note that penetrating oil is not a lubricant.