HOWEVER careful the user may be to cover the sewing machine whenever it is not in use, dust and fluff will inevitably accumulate, and although these may be removed daily from the external parts, there is a great temptation to allow those parts which are out of sight to remain dirty until trouble occurs. Oil, of the kind recommended by the makers of the particular model, is essential to the proper lubrication of working surfaces, spindles and bearings, but before any oiling is done, the dusting of all parts is essential and should be particularly thorough. The oil holes, which must be kept clear, are indicated in the maker’s instruction handbook; each one should be located and given its single drop of lubricant.
The owner of a new machine may wonder how frequently cleaning and oiling will call for attention. The average user, running the machine for an odd hour or so, on perhaps two or three days of the week, should dust it both before and after use, and oil it not more often than about once a month. If used three or four hours a day regularly, oiling and cleaning once a week will be sufficient. If the machine is in regular use for most of the ‘day, these attentions should be given daily before work commences.
The presence of too much oil, or oil of the wrong kind, must be avoided. A machine which is not used very often is, as a rule, the first to make known the fact that it has been unwisely lubricated. Hard running after a period of idleness indicates that oil has gummed in the bearings. This effect will be emphasized if the machine stands in too cold a room or in a cold draught. If the machine must be used during winter in a room without a fire, it should be given some chance to work efficiently by being ‘.varmed up a little for an hour or so before working. An oil stove or electric radiator should be placed near it to render the oil less cloggy.
If the machine still runs sluggishly, go over each oiling-point and apply a very small quantity of paraffin, first taking the precaution of spreading a sheet or two of newspaper on the floor to catch odd drips. The machine should then be run briskly for, say, three minutes. This should have the effect of thinning the oil and reducing bearing surface friction, and the gumming or clogging should disappear. Traces of oil will probably be observed here and there on the exterior when the rapid running ceases, and a scrap of non-fluffy rag should be used to remove the last traces.
Sewing machine oil, of the kind specified by the maker, should then be applied to each hole, after which the running should be easy and smooth. If the machine still runs unsatisfactorily a general overhaul is indicated. Only in this way can it be thoroughly cleaned of dust, grit and bits of fibre which are liable to cause stiff working no less than thick oil. Overhaul inspection must be done methodically, and if the maker’s handbook is not available for a guide, a rough sketch*************** should first be made of each part which it is intended to remove, so as to facilitate replacement.
Careful use of the screwdriver will prevent burring of the slots in the screw heads, and for safety the screws should be placed aside on a piece of clean cloth or newspaper or in a tin lid, while the work is proceeded with. If any parts are rusty they should be immersed for a few hours in paraffin, then polished with a clean rag. No harsh abrasive should be used. A little metal polish and plenty of rubbing may supplement the cleansing influence of the oil. It is not at all probable, of course, that rusting will occur in a machine unless it has been disused and neglected for a long time, but it is possible in the case of a machine purchased secondhand, and is a condition which should be looked for before purchase.
For purposes of thorough inspection, and for occasional overhaul, the thread should first be removed, then the slide plate, the bobbin, the needle and the presser foot . Removal of the throat plate will reveal the shuttle race, which can then be cleaned and oiled. Extraction of screws from the face plate will reveal oil-holes and joints for lubrication on the needle bar, presser bar, and the thread take-up.
To get at the underside of the machine head, in the case of a treadle machine, the belt is removed from the band wheel, by means of the belt shifter whose lever has to be moved to the left, whilst the machine is gently running; this displaces the belt to the right. It is then possible to hinge the head back, and if the balance wheel is then slowly turned the points where single drops of oil should be applied become obvious. Surplus oil should be removed with a piece of rag; the head may then be restored to the working position, and the belt replaced, while the treadle is gently operated so that the band wheel revolves towards the operator.
The hand machine needing these attentions will be lifted from its base after the removal of the securing screws, the latter being screwed tightly home again when the underside cleaning and oiling have been completed. It is customary to attend to the underside of the head first, the oiling points at the top of the machine being dealt with next. A clean and non-fluffy duster should then be used to remove all traces of oil on the exterior. A piece of odd material passed through the threaded machine will rid the working surfaces of oil, before the next piece of sewing is to be done. In the matter of oiling the bobbin winder, very careful use of the oil-can is necessary. One drop only, at each of the two holes, is needed. If oil gets on to the rubber ring it will cause slipping, and the rubber itself will soften and deteriorate. Should oil contaminate the rubber, it must be wiped off instantly and thoroughly. If the rubber ring on the bobbin winder deteriorates from the effects of oil, the only remedy is replacement by a new ring.
Trouble with the treadle, the pivoted platform operated by the feet, can be avoided by regular oiling at the side-points, thus ensuring easy action. Other moving parts of the stand should likewise be kept dusted and lubricated . A noisy treadle may be quietened by tightening one or both the screws which form its pivots. Before the screw can be tightened up, the nut around its head must be loosened with a spanner, the nut being tightened again when the screw has been attended to. If, on working the treadle, the noise still persists, the opposite screw should be tightened. No more than the reduction of ‘play’ should be aimed at, for if the screws are tightened unduly the treadle will be difficult to work.
It is essential that the machine, treadle or hand, should stand perfectly level, on floor or table respectively. When not in use the head of a treadle machine should always be lowered into its cabinet stand, and that of a hand machine kept covered up, to avoid accumulation of dust and the possibility of interference by inquisitive children.
A number of common troubles are traceable to the needles. The latter must conform to the type specified by the makers of the particular machine, and should be of the correct size for the thread and the material. The needle that is satisfactory for all classes of work has yet to be invented. A table setting out the relative sizes of needles and threads, and the class of sewing (the material), should be obtained from the makers of the machine, or their agents, and carefully followed. Needle breakage and many other troubles will thus be avoided.
Tugging at the material while the needle is still engaged may result in the needle becoming broken or bent. In the latter case it will strike the throat plate on the next downward movement and this will burr the hole in the plate and the slot in the pressor foot. A bent or blunted needle may also be responsible for the breaking of the upper thread. Breakage of both upper and lower threads is sometimes due to over-tensioning.
Tension (pull) on the upper thread (from the needle), for adaptation to different materials, is adjusted by means of a thumb nut . This is turned to the right when the tension is to be lessened. It is necessary that the presser foot should be down when upper thread tension is adjusted. Upper and lower tension should be approximately equal, the lower tension controlling the thread from the shuttle or bobbin case. Adjustment of the lower tension is effected by means of a small spring screw, which is tightened slightly to increase the tension, and loosened a trifle to lessen it. Any adjustment of the thread tensions should be accompanied by a test of the effect on the stitches.
If any difficulty is experienced with one of the older types of sewing machine, which cannot be rectified from the foregoing instructions, advice will be readily forthcoming from the maker’s local representative for repair service.