OR, HOW TO KEEP YOUR SEWING MACHINE HAPPY AND HEALTHY BETWEEN TUNE-UPS By Nelson Maynard II, Owner/Proprietor, Nelson Maynard Sewing Machine Service, Lawrenceburg, KY
Workrooms don’t work unless their sewing machines do. As a sewing machine technician, my job is to keep them running and to repair them when they aren’t. I recommend an annual tune-up for most machines that are used professionally, but there are some basic preventive maintenance steps that sewing professionals can take to ensure that their sewing machines stay in good condition between regular tune-ups.
First of all, I always recommend having a back-up machine in your stable in case your regular machine is not operating correctly. You don’t want to put your work on hold while you’re waiting for your machine tech to schedule an appointment, especially if it turns out that replacement parts have to be ordered in. So, a backup machine is critical.
Secondly, it’s important to familiarize yourself and your machine operators with the machines you use, especially with regard to cleaning and lubrication. Review the instruction manual for your machine and follow it accordingly. Sewing machines that are kept clean and properly lubricated are much less likely to give you trouble. Let’s start with cleaning.
Cleaning the machine is often more of a housekeeping matter than a critical maintenance check, but it’s important to remember that sewing machines will accumulate lint, dust, and bits of thread as an ordinary matter of course. Loose threads especially can cause the machine’s mechanisms to bind if
they get caught in the gears or shafts, and should be cleared out regularly. Compacted lint can also accumulate in between the rows of the teeth on the feed dogs, leading to feed problems and even, in extreme cases, bent needle plates or feed dog carriers.
For this reason, I would recommend that every sewing machine operator know how to remove their machine’s stitch plate and clean the feed dogs while also checking for accumulated lint in the area of the hook shuttle or rotary hook assembly. Be sure to check for any stray thread that might be wrapped around the associated mechanisms. Lint brushes, tweezers, toothpicks, or even old needles are very useful for doing this job.
Compressed air can be very helpful as well, but only if the area around the hook is open, to allow the blown-off dust and lint to escape. This is usually the case with industrial or commercial machines, which can be tipped back on their hinges to expose the works of the lower carriage. For domestic machines, which are usually fully enclosed in a plastic or metal housing, a set of precision hose attachments for a vacuum is what I would recommend rather than compressed air. This will prevent bits of oily detritus from being blown further into the machine covers, where it may have more opportunities to foul up the works.
Once the feed dogs and hook well are cleaned out, replace the stitch plate. On most industrial and domestic machines the stitch plate simply mounts in place with machine screws or clips. Be aware that certain machines such as the Singer 221 Featherweight and most top-loading industrial walking foot machines have a position finger on the rotary hook base. This finger must be located between retaining tabs on the underside of the stitch plate in order to hold the bobbin case basket in the correct position for stitch formation. It is very important that these be mounted correctly in order to ensure correct stitch formation and prevent
damage to the machine.
While you have the stitch plate dismounted, it’s a good idea to check it for wear or damage, such as burrs from needle strikes or bent center sections, and replace it if necessary.
You should also check the headframe mechanisms of your machines for wound-up thread and similarly remove any accumulated dust and lint. The headframe consists of the shafts and rods at the head end of the machine including the needle bar, needle bar carrier, presser foot bar, and associated cranks and connecting rods. On many domestic machines the headframe cover, which is usually called the faceplate, is hinged for easy access and may simply be swung open;. Sometimes one or two mounting screws must be removed in order to free up the faceplate for removal. In either case, you should know how to access these mechanisms for periodic inspection and cleaning.
Thread is the real culprit to look for in this case;. Dust and lint can get saturated with cast-off oil and possibly make a mess on your work. Wound-up thread around the eccentric crank, take-up lever pivot point, or needle bar connecting rod can put your machine in a tight bind and put your machine out of commission. When the faceplate is removed or swung open, brush or vacuum out any accumulated lint and inspect the junction points of the various mechanisms for any wound-up thread, removing it as needed. Tweezers and hemostats are very helpful in this regard. A sharp hobby knife, such as an X-Acto #1, or similar, may sometimes be necessary. I’ve also found that a good set of fine thread snips, such as Tooltron’s “Easy Kut” trimmers, can be very useful for removing tightly wound thread as well.
Cutting wound-up thread can sometimes result in more of a tangled mess than you had before, so I always think it’s best to simply unwind the thread if possible. Locate the end of the thread, and take hold of it with your tweezers or hemostat, and slowly turn the hand-wheel in reverse while pulling the thread gently; this will often allow you remove the entire section of fouled thread without having to do any cutting.
Keeping these two critical areas of your sewing machines clean and free of potential obstructions will help ensure smooth operation and I would recommend inspecting these areas regularly, say, once a week on any workroom machines. Make it a regular part of your routine at the beginning or end of the week and you’ll be much less likely to encounter operational problems with your sewing equipment.
Now for lubrication. In order to keep your sewing machine running smoothly and extend its working life, it is very important that its moving parts should be properly lubricated. Fortunately, this isn’t generally difficult.
Most domestic sewing machines manufactured over the past twenty years or so require very little in the way of direct lubrication. They are usually equipped with sinter bushings, which are porous pressed-metal fittings that are permanently impregnated with oil during the manufacturing process. As the machine runs, the bushings warm up, and the embedded oil expands, creating a film of lubricant that protects the shaft that the bushing supports. The instruction manuals for older machines usually included a lubrication diagram showing ten or twelve points that needed regular application of machine oil but most modern machines do not; it’s simply not necessary, owing to the new bushings.
Professional and industrial machines are not generally equipped with sinter bushings, but many of them are equipped with oil sumps in their bases, or with felt oil pads in their upper works which distribute the oil throughout the machine via a system of cotton wicks. If you keep your oil pan topped up and your pads well saturated, regular daily lubrication is
once again minimized.
However, if your machine is not equipped with either sinter bearings or an oil wick harness, it will be necessary to regularly lubricate its wear points, according to the lubrication diagram in its operator’s manual. This is especially important for older domestic or industrial machines. In a dedicated production setting machines would normally be lubed at the beginning of each shift; for most professional workrooms, where the machines are used every day but not all day, weekly lubrication should generally be sufficient. Use only lightweight oil designed specifically for sewing machines for this application;. Other oils, such as 3-in-1 or WD-40 are generally too viscous for use in sewing machines and can leave behind a gummy residue as they dry out,. which This can leave the works of the machine in a bind, leading to stiff running and excessive strain on the motor. The correct lubricant will keep the machine running freely with regular use.
As with cleaning, the hook system and headframe are the most important points to consider when lubricating your machine. In domestic machines these are two areas that are not equipped with sinter bushings, and in commercial machines may not be reached by the oil wicks. For rotary hook machines, a drop or two of oil in the flangeway where the bobbin case basket meets the outer hook will suffice; for oscillating-hook machines, remove the hook shuttle and apply a drop of oil directly to the edge of the hook then reinsert it and secure the hook race cover.
After oiling the hook, it is important to wick off any excess oil by sewing a few inches on scrap material until no fresh oil is visible on the work.
For the headframe mechanisms, apply a drop of oil at every point where you
see metal moving on metal. The needle bar and its connecting rod as well as the pivot points for the eccentric crank, take-up lever, and take-up support rod all need a drop of oil;. Mechanical machines will have an oil port cast into the headframe components to allow the oil to work its way inside the linkages.
As with the hook, it’s important to remember that one or two drops of oil will usually suffice;. e Excess oil can attract dust and grime and, more importantly, can be cast off onto the work while sewing, which is something I’m sure I don’t have to remind you is something to be most earnestly avoided.
Again, in factory settings, this sort of preventive maintenance would be carried out at the beginning of each shift but is not necessary as frequently in a workroom setting. About once a week, perhaps in conjunction with cleaning and inspection, should be sufficient in most cases.
By keeping your machines cleaned and lubricated on a regular basis, you will be doing the best thing that you can to keep them in good condition between professional cleanings and adjustment. Your machines will run smoothly and will be less likely to malfunction, allowing your business to run more smoothly and maintain a good turn around on your clients’ projects. As the old quartermaster said, take care of them, and they will take care of you!
And while I don’t mind coming out to service my clients’ machines—it is, after all, what I do—I find it’s much simpler to work on a well-maintained machine than one that has been neglected.
So keep them clean, keep them lubed, and everyone will be happier for it!
Now, sit down to your machine, and make it sew!