Sewing Machine Maintenance
Please refer back to this page over time; information will be added.
Oiling
Points of lubrication
Every surface on a machine, which is in movable contact with any other point, must be
lubricated. This is true even if the operators manual does not indicate the need to
lubricate every point. A small drop of oil on each point is sufficient. Take off the
machine covers and rotate the handwheel in the normal direction of rotation. Observe and
note every movable contact point on the machine. This includes the visualizing of shafts
within bushings, etc. Perform this exercise thoroughly while lubricating the machine, and
you will soon find it quick to lubricate every point without fail. Please note that
manuals usually have very poor depictions of oiling points.
Frequency
Each lubrication point should be oiled every four hours of use. The hook race, and
corresponding bobbin case or bobbin case base, and the needle bar, all require particular
attention to lubrication. These are some of the primary wear areas on lockstitch sewing
machines, (the needle bar on chainstich machines). These points may be oiled more
thoroughly and/or frequently. If oil contamination of the material does not prove to be a
problem, it would be best to oil the hook race at each change of the bobbin, especially
with a new hook assembly. Of course this is easy to accomplish on machines in which the
bobbin is loaded from the top of the bed, and difficult with bobbins that are
inserted under the bed.
Oiling systems
Manual oiling systems require the operator to oil each point individually, and on a
regular (preferred 4-hour) basis. Automatic oiling systems can supply all points of
lubrication or can be combined with manual oiling. The oil in automatic systems can be
distributed through gravity, through splash, through wicking (such as cotton cord), or
through pressure supplied by a pump. All automatic oiling systems require the reservoir to
be filled to a certain level with oil. Wick fed systems range from small reservoirs (the
wicking itself may serve as reservoir) to more substantial cavities. The smaller the
reservoir, the more often oil will need to be added. Larger oil reservoirs of any system
type may have marked indicator levels, so that the operator can verify that enough oil is
available in the reservoir. Pressure lubrication systems may have sight windows or
bubbles. A flow or splash of oil seen through these windows or bubbles will indicate that
there is likely a good pressure of oil in the system. Pressure systems may also have
adjustment needles or valves to control the flow of oil to critical points such as the
hook race. Any system can have an oil return mechanism to recirculate oil and to prevent
build-up of oil in pockets from which it may leak or overflow. The oil return mechanisms
can be gravity flow, wicking, or both. Pressure systems may also incorporate a suction
return, operated by the same pump that supplies oil pressure.
Oil
There are two basic categories of oil, and some secondary ones. Plain mineral oil ( the
same as baby oil) is commonly used. It is clear and sometimes marketed as
"stainless" oil since it will not stain material as severely as other oils. It
is adequate for normal speed, pressure and heat applications. Additive oils are usually
identified by a "color" to the oil. They can be clear, but are not normally
clear in color. The most important purpose of the additives are to provide adequate
lubrication in high speed, high heat conditions.
Cleaning
Hook system
Thread handling system
Needle bar
Adjustments
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