System 

How to use a sewing machine. How to set up a sewing machine to work with different types of fabric? How to raise the presser foot on a sewing machine

The claw mechanism is integral part fabric motor mechanism and kinematically connected to a device for loosening the upper thread; The machine uses a hinged foot 1 (Fig. 19), attached to the rod 2 with a screw. The guide for the rod is sleeve 3, pressed into the head of the machine. A bracket 18 is loosely placed on top of the sleeve, on which a plate 5 with a bevel is attached with a screw, pressing on the rod of the upper thread tension regulator: when lifting the presser foot. The arm extension is located in the guide groove of the machine head housing. A link 8 is attached to the bracket with a hinge screw, into the hole of which a lever pin 10 is inserted. The lever is held on two hinge screws 9 screwed into the body of the machine arm. The right arm of the lever 10 is connected to a rod 12, the position of which is fixed by a cotter pin 14. At the lower end of the rod 12, passed through a hole in the machine platform, a spring 13 is put on, resting against the cotter pin 14.

A guide 7 is fixed to the rod 2 with a tightening screw 18, the extension of which is located in the groove of the machine head and prevents arbitrary rotation of the rod with the claw around their axis.

The pressure of the presser foot on the fabric is produced by a leaf spring 16, which is put on the right end of the hinge screw 15. The left end of the leaf spring rests against a ball 17 inserted into the end hole of the rod 2 of the presser foot. The thrust screw 11 creates pressure on the leaf spring 16 and

presser feet 1 per fabric.

To lift the presser foot manually, a pin with a lever 4 is inserted into the hole of the machine head; a spring-loaded cam 20 is placed on the pin, which can be rotated together with the pin and the presser foot lifting lever manually. When lever 4 is turned clockwise, cam 20 presses on the extension of bracket 6. The bracket, moving upward along the fixed sleeve, presses on guide 7, which, together with rod 2 and tab 1, rises. At the same time, plate 5, acting with its bevel on the tension regulator rod, releases the upper thread located between the convex tension washers.

Figure 19. Foot mechanism of the machine 97-A class.

The machine is equipped with a knee press for lifting the presser foot, installed under the industrial table cover. If it is necessary to raise the foot, the worker moves the knee press to the right. The lever arm raises the rod 12. The rod turns the lever 10 counterclockwise, and link 8 raises the rod with the foot.

The height of the presser foot above the needle plate is adjusted by moving rod 2 with the presser foot after loosening screw 18. In this case, you should pay attention that the horns of the presser foot do not touch the needle. The position of the foot horns relative to the needle is adjusted by rotating the rod with the foot around its axis. The force of pressure of the presser foot on the fabric is regulated by screw 11. The lifting height of the presser foot is changed with the lower position of the needle, and therefore the lower position of the rack.

Figure 20. Lubrication of machine mechanisms 97-A class.

As stated earlier, in the car 97-A class. lubrication of the main mechanisms is carried out forcibly. For this purpose, a double vane pump N is installed under the machine platform (Fig. 20. b), one part of which is designed to suck oil from the sump and pump it to the rubbing surfaces of the machine parts, and the other to suck out the accumulated oil from the front of the machine head and returning it back to the sump located under the machine platform.

A double vane pump (Fig. 20, a) consists of a housing 1, two rings 2, a washer 6, a shaft 3 and a cover 8. The parts are connected to each other by two pins 10 and three screws 9. Vanes 4 are inserted into the grooves A of shaft 3, between which there are springs 5, constantly pressing the gates 4 to the inside of each ring. The center of the hole of the rings 2 is offset relative to the center of the shaft 5, so the outer surface of the shaft 3 touches the edge of the inner surface of the rings on one side. Washer 6 separates the suction chamber 11 from the discharge chamber 12.

At the upper end of shaft 3 there is a gear 23 fixed (see Fig. 20, b), which is engaged with a worm 22 mounted on the camshaft with a gear ratio i=7:1.

When the camshaft rotates, the worm pair transmits rotation to shaft 3 of the pump. Oil from the sump through a polyvinyl chloride tube 8a enters the discharge cavity 12 (Fig. 20, a) of the pump, and from the discharge cavity into the distribution fitting 13 and the tubes 20, 24, 25 connected to it (see Fig. 20, b). Through tube 20, the lubricant enters reservoir 19, from where it enters the channel onto the surface of the main shaft and through the spiral groove of the shaft through a transverse hole into the shaft cavity.

The wick, located in the cavity of the main shaft, absorbs oil, which through the holes and under the action of centrifugal force enters the ball bearing of the main shaft and the needle bearing of the needle bar connecting rod.

Oil flows through tube 17 to the needle bar bushing, and through tube 21 to the rear ball bearing of the main shaft. The oil accumulated in the front part of the machine head is sucked through tube 18 by chamber 11 of the pump (Fig. 20, a) and is forcibly drained into the pan.

The surface of the double eccentric of the fabric engine mechanism, as well as the inner surface of the front and middle camshaft bushings, are lubricated by oil coming from the pump through tube 24 and the inner hole of the camshaft. The remaining part of the oil in the internal cavity of the camshaft flows to the gears of the shuttle mechanism. Through tubes 15 and 26, the oil flows to the rack lift shaft crayon and to the hinge joints of the frame 14 of the shaft 16 of the fabric motor unit.

Figure 21. Scheme for threading the needle thread of a 97-A class machine.

The shuttle mechanism also has forced lubrication. Through tube 25 (see Fig. 20, b) oil from the pump is supplied to spiral groove A of shuttle shaft 33 (Fig. 16) and, moving to the left along the groove, lubricates the inner surface of the right bushing. In this case, one part of the oil enters hole B, penetrating inside the shuttle shaft 33, the other part enters the space between bushings 32 and 34, providing lubrication to the inner surface of the left bushing 32.

The oil located inside the axial channel of the shuttle shaft 33 spreads in two directions. Moving to the left, the oil along the wick F through the hole in the screw 31, through the channel 35a of the shuttle 25, enters the rim of the bullet holder 24. Moving along the axial channel to the right, through hole B the oil enters the annular channel of the right bushing and flows down through channel G into the tray.

The wick inserted inside the axial channel of the shuttle shaft must be replaced with a new one each time it becomes clogged with dirt.

The amount of oil supplied to the shuttle 25 is regulated by screw 30. If screw 30 is screwed in, the cross-section of channel E will be reduced, and the amount of oil supplied to the shuttle will increase.

When adjusting the oil supply to the shuttle, it is necessary to screw screw 30 in completely, and then unscrew it 2.5 turns. Checking the oil supply to the shuttle kit is carried out as in a 1022 cl machine. In Fig. Figure 21 shows a diagram of threading a needle.

Machine 852 (×5) cells. PMZ.

Industrial sewing machine 852 (×5) cells. PMZ is designed for sewing two parallel lines with shuttle weave of linen, suiting, raincoat materials made of natural and mixed fibers (Fig. 22). The peculiarities of the machine are that the needles, in addition to vertical movements, are deflected along the lines; Central bobbin shuttles are used, rotating in a horizontal plane and equipped with diverters. Threading the upper and lower threads. Bobbins or spools of thread are installed on bobbin stands. The threads are passed through the holes of the tubular thread guides 11 (Fig. 23), 12, from top to bottom they are tucked into the holes of the thread guide square 13. One thread is passed in a clockwise direction between the tension regulator washers 14, the other counterclockwise - between the tension regulator washers 17. Next both threads are inserted clockwise into the groove of the regulator 15 and from bottom to top they are brought under the thread take-up spring 16, passed under the plate thread guide 9 and threaded from right to left into the two ears of the thread take-up 10. The threads are guided down the sub-plate thread guides 9, 8, into two holes on the needle holder 7 and from the side of the long grooves facing each other, they are tucked into the ears of needles 5, 6. The lower

Figure 22. Machine 852 (×5) cells. PMZ

the threads are wound on two bobbins, as in a 1022-M class machine. OZLM. Then one bobbin 1, with the latch 2 raised, is inserted into the bobbin holder 3. When the loops of the lower threads are removed from the holes of the rack, the threads are pulled under the leaf springs 4. Do the same with the second bobbin. Adjusting the needle mechanism. The height of the needles 1 (Fig. 24) relative to the noses of the shuttles is adjusted by vertical movement of the needle holder 2 inside the hollow needle bar 5 after loosening the tightening screw 3 of the adjusting ring 4. The position of the needles 1 relative to the walls of the holes in the rail is adjusted by turning the frame 6 and the upper shaft 7 after loosening the tightening screw 8 rocker arms 9. Adjustment of shuttle and diverter mechanisms. The timeliness of the approach of the shuttle noses to the needles is regulated by turning the shuttle shafts 13 (Fig. 25) after loosening the two thrust screws 11 of the gear 12. When raising the needles from the lowest position by 2 mm, the shuttle noses should be 1.6 mm higher than the needle ears. The gap between the needles and the noses of the shuttles, which should be equal to 0.05-0.1 mm, is adjusted by moving the crankcases 3 along the shaft 16. To make the adjustment, loosen the screws 14 of the gear wheels 15, the screw 8 securing the crackers 7, 19 and the screw 4. Then move the crankcase together with the gear wheel 15 along the axis of the shaft 16. The timing of the movement of the tappers \7 to press on the protrusions of the bobbin holders is achieved by turning the shafts 20 after loosening the screws 6 of the gears 5. The tappers 7 must press on the protrusions of the bobbin holders at the moment of inserting the needle loops into the shuttle sets, that is, to form a gap between the fingers of the bobbin holder and the walls of the grooves of the needle plate. The position of the tappers 17 relative to the protrusions of the bobbin holder is regulated by their movement along the groove of the levers after loosening the screw 18. The amount of oil supplied to the shuttles is regulated by screws 10 after loosening the screws 9. If screw 10 is screwed in, the amount of oil supplied to the shuttle will decrease. Also regulated

Figure 24. Machine needle mechanism 852 (×5) cells. PMZ

supply of oil to the interfaces of the tapper links. The tension of the lower threads is adjusted by screw 1 due to the deformation of leaf springs 2. To change the distance between parallel lines, replace the needle holder, presser foot, rack, and needle plate; the crankcases 3, together with the gears 15, are moved along the axis of the shaft 16, as when changing the gaps between the needles and the noses of the shuttles. Adjusting the material movement mechanism. The length of the stitch is adjusted by turning lever 17 (Fig. 26) relative to scale 18 after screwing in nut 20. If the lever is turned counterclockwise and its position is fixed with stop 19 by unscrewing nut 20, then the stitch length will increase due to turning frame 22 counterclockwise. To secure the stitch, the worker presses handle 21, causing lever 17 to rotate clockwise. In this case, the material will begin to move towards the worker. The lifting height of the rack 7 above the needle plate is adjusted by turning the rocker 10 on the lift shaft 11 after loosening the tightening screw 9. The horizontality of the teeth of the rack 7 is adjusted by its vertical displacement using

Figure 25. Mechanism of shuttles and diverters.

screw 5 after loosening screws 8, 6. The timeliness of lifting the rack 7 and the timeliness of moving the material are regulated separately by turning the eccentrics 12, 15 after loosening the screws 13, 16 or by turning the main shaft of the machine. At the moment the material is pierced with needles, the rail should begin to move. The position of the rack 7 in the slots of the needle plate is adjusted by turning the rocker 3 after loosening the screws 4 on the movement shaft 2, if the rack should be moved across the platform. To move the rack 7

Figure 26. Mechanism of the fabric motor of the machine 852 (×5) cells. PMZ

screws 4, 9 are loosened along the platform and the rocker arms 3, 10 are moved along the shafts 11, 2. The equality of stitch lengths during forward and reverse movement of the rack 7 is adjusted by turning the frame 22 after loosening the screws 1. The tension of the spring 14 required to return the lever 17 to initial position after securing the stitch, it is adjusted by moving its threaded hook 23. Adjusting the presser foot assembly. The pressure of the foot 1 (Fig. 27) on the material is regulated by screw 7 due to the deformation of the leaf spring 5 relative to the axis of the square 6. If screw 7 is unscrewed, the pressure of the foot will increase. The height of the rise of the foot 1 above the needle plate is adjusted by the vertical movement of the clutch 3 along the rod 2 after loosening the tightening screw 4. If the clutch 3 is lowered, the foot 1 will rise by a greater amount. The position of the horns of the foot 1 relative to the line of movement of the needles is adjusted by turning the rod 2 after loosening the screw 4. Adjusting the winder for winding the bobbin. The number of threads wound on the bobbin is regulated by the vertical movement of the limiter 12 after loosening the screw 11. If the limiter 12 is moved upward from the axis of the spindle 13, the number of threads on the bobbin will increase. The engagement of the teeth of the gear wheel 8 with the gear wheel of the winder is regulated by the axial movement of the gear wheel 8 after loosening the screws 9 along the main shaft 10. The uniformity of winding the threads on the bobbin is regulated by turning the thread guide square 14 after loosening the screw 16. The tension of the thread when winding on the bobbin is adjusted by the nut 15.

Figure 27. Machine foot assembly 852 (×5) cells. PMZ

3.14. Button semi-automatic 1095 class.

The 1095 class semi-automatic is the basic design. From a technological point of view, it is universal: flat buttons can be sewn on it different ways close to the fabric and on the “leg”; close to the fabric with a button and on the “leg” with a button; hidden stitches. Possibility of sewing with different diameters and different distances between the holes.

Technical specifications semi-automatic

Table 4

Composition of a semi-automatic device

The semi-automatic sewing head consists of the following mechanisms and devices:

Mechanism for vertical movements of the needle and thread feeder;

Looper mechanism;

Expander mechanism;

Fabric motor and button holder mechanism;

Needle deflection mechanism;

Auto stop unit;

Thread trimming unit;

Lifting unit for button holder and thread remover;

Thread clamping mechanism when trimming;

Devices for unwinding thread from a bobbin and regulating its tension.

The movement of the processed materials occurs due to the movement of the teeth located in the lower plate and the pressure of the foot. The initial setting of the sewing machine at the manufacturer is carried out to work with frequently used medium-weight fabrics: linen, cotton, gabardine.

Needlewomen are not limited to sewing products from such materials, especially since modern units can work with fabrics of different densities. For example, when sewing seams on thin fabric, it is undesirable for the presser foot to be too strong, otherwise puffs may appear on the fabric. Knitted materials are stretchable, so excess pressure will cause elongation in the seam area.

When working with high-density fabrics - canvas, it is necessary, on the contrary, to increase the pressure so that sufficient friction force arises to facilitate the normal movement of the parts being sewn.

Why is it important to adjust the presser foot pressure?

Every dressmaker should understand that a sewing machine is a mechanism that needs to be adjusted in order for the work done to look neat. Installed feet are made from different materials: metal, plastic, Teflon. They will slide across the fabric in different ways, so the pressure must be adjusted to ensure uniform movement of the parts being sewn. This determines how uniform the stitches will be.

If in mechanical models the presser foot pressure was adjusted manually by the seamstress, then in modern models a regulator is already provided on the body. An experienced dressmaker first adjusts the equipment, conducts trial operations on an unnecessary piece of fabric, and then gets to work.

How to reduce foot pressure on mechanical sewing machines?

Old-style devices consisted only of metal parts: components, parts, housing. Therefore, in order to increase or decrease the force with which the foot presses on the fabric, it was necessary to rotate the screw located on the rod. Due to this, adjustment occurred: compression or stretching of the spring, which exerts pressure.

Finding the rod is easy. In older models of the Podolskaya type, it comes out into a hole located in the upper part of the body. In units with an electric drive, you need to remove the top cover, under it in the sleeve all the main components are located.

Adjusting presser foot pressure in modern machines

Electromechanical devices are designed a little differently. You don't have to find the core of the foot. Many models have a regulator that makes it easy to adjust the pressure of the presser on the fabric. It is located on the machine body or under the front panel cover. How to configure is described in the instructions.

In computerized models, such a regulator is usually absent, since the device adjusts itself required modes based on the installed program.

Therefore, when deciding whether you need to adjust the presser foot pressure in the machine before sewing, study the principles of operation of the device and read the instructions carefully.

Let's try now to figure out for what purposes it is required adjust presser foot pressure onto the fabric.

Presser foot pressure controls were a standard feature on vintage sewing machines. In modern sewing machines it is less common and is not given much importance. So which sewing machine should you buy, with a presser foot pressure regulator or not? What do we lose if we choose a machine without a pressure regulator for the presser foot on the fabric?

The pressure regulator allows us to adjust the degree of impact of the foot on the fabric, which the foot presses against the rack of the fabric feeding conveyor. Thus, the size of the resulting stitches can depend on the pressure of the presser foot.

The foot can be made of various materials - chrome steel, plastic, Teflon. Accordingly, different paws will slide on different materials with different friction forces. Another factor is the distortion of the fabric when the fabric is pressed against the feed teeth. It is necessary to select the optimal presser foot pressure so that the fabric is effectively fed under the needle by the conveyor, and so that the fabric does not deform when it is pressed against the rack. Even the most modern computer sewing machines with automatic tuning Presser foot pressure cannot correctly calculate the friction of the presser foot and the resulting stretch or distortion of the fabric.

The most The best decision- This is experimentation and testing. If you have a presser foot pressure regulator, you can select a setting that will allow the given presser foot to glide optimally over the selected fabric. So choose a machine with a presser foot pressure regulator - it will only get better, it won't get worse in any case.

Let's bring simple example. If you use GPS navigator, then you follow his instructions, completely rely on him. You drive from point A to point B and don’t think about anything, you don’t remember landmarks. As soon as your navigator breaks down, you first start to panic. Then you turn on all your senses and powers of observation, and you will study the unknown area so much that you will never get lost here, even without a navigator. The same can be said about sewing. Adjust, experiment, try - and you will always achieve what you need.

Suppose you are sewing together 2 pieces of elastic knitwear, and towards the end of the seam you discover that one piece has stretched out relative to the other - it has turned out longer. The reason for this may be incorrectly chosen pressure of the presser foot on the top layer of fabric - the top and bottom layers are fed under the needle at different speeds, and the layers shift.

How to regulate presser foot pressure? Adjust the presser foot pressure and see the result. If the seam looks bad, start to increase the pressure little by little. If the result gets even worse, then do the opposite - reduce the presser foot pressure.

Sewing machines can seem intimidatingly complicated to those who don't know how to use them. Whatever the case may be, don't let the fear of unknown operations and skills required to use a sewing machine stop you from creating textile wonders! Use this step by step instructions, describing the installation mechanism and operation on sewing machine, so that you can start creating things with your own hands.

Steps

Sewing machine parts

    Find the power button. It may sound stupid, but locating the power button is the most important step! She may be in different places, depending on the model of your sewing machine, but most often you can find it at right side sewing machine.

    Find the reel seat. This is the small plastic or metal stick that sticks out from the top of the sewing machine and is designed to hold the spool of thread.

    Find the thread guide. The thread guide guides the thread from the spool mounted on the top of the machine to the bobbin winder. This is a geometric piece of metal that sticks out on the top left side of the sewing machine.

    Find a bobbin winder. To the right of the reel seat is another, even smaller, metal or plastic pin, next to which there is a small horizontal wheel. This is a winder reel and its limiter. They work together (together with the bobbin with thread) and are designed to wind the thread onto the bobbin before sewing.

    Look at the buttons that allow you to adjust the stitches. They can be in different places depending on the model of sewing machine you have, but they usually look like buttons with little pictures on them and are located on the front of the sewing machine. These buttons allow you to change the type of stitches you can use, the length of the stitches, as well as their direction (forward and backward). Check the instructions for your sewing machine model to find out what each button does.

    Determine the location of the thread take-up. When you are ready to thread your sewing machine, start pulling the thread from the spool at the top, through the thread guide, and then into the thread take-up. This is a lever (with two grooves cut out) located on the front left side of the sewing machine. Usually next to it you can see printed numbers and arrows, explaining how it is necessary and in what order to thread the thread into the sewing machine.

    Find the tension regulator. The tension dial is a small wheel with numbers located next to the thread take-up. It controls the thread tension while sewing; if the tension is too high, the needle will bend to the right. If the tension is not sufficient, the thread will tangle on the back of the fabric you are sewing.

    Find the needle clamp screw. This metal tool, which holds the needle while sewing. It is located under the sleeve of the sewing machine and is shaped very similar to a large fingernail. It attaches to the right side of the needle.

    Find the paw. This is the metal part located under the needle holder and looks like tiny skis. When you lower the foot, it holds the fabric in place and guides it as you sew.

    Find the presser foot lever and practice lowering and raising the presser foot. It should be behind or to the right of the needle holder and needle. To try the lever, lower it down and lift it up.

    Find the needle plate. The needle plate is the silver pad located directly below the needle. Very simple, right?

    Find the transporter. The feed dog is a small metal guide that is located on the needle plate, under the foot, and guides the fabric as you sew. Pay attention to the two metal rows under the foot - this is the conveyor.

    Locate the coil limiter and releaser. The spool is a small bobbin of thread that is located at the bottom of the sewing machine and supplies the second thread to the needle, which is needed to create stitches on the inside. Under the metal plate is the spool stop, and there you will also find a button or lever that releases it. You will need it to secure the spool before you start sewing.

    Setting up the sewing machine

    1. Place the sewing machine on a stable table, workplace, a desk or a special stand for the sewing machine in front of you. Sit on a chair that is of an appropriate height relative to the table you are using. The sewing machine should be positioned so that its needle is on the left and the rest on the right, relative to you. You'll have to check a few settings first and become a little familiar with the sewing machine, so don't plug it in at this point.

      Insert the needle securely. The needle has a flat side, so it can only be inserted one way: the flat side must be facing backwards. On the other side, there is a groove at the bottom of the needle, usually located opposite the flat side of the needle. This groove always faces the direction the thread passes (the thread passes through this groove as the needle stitches up and down the fabric). Insert the needle as described and tighten the screw holding it securely.

      Install the coil. Sewing machines use two sources of thread - upper and lower threads. The lower one is on the reel. To wind the spool of thread, place the spool on the upper spool pin, which is where the thread is wound. Follow the directions and wind the thread from the thread spool, passing it through the thread take-up, onto the bobbin. Turn on the thread winder and wait until it stops when the bobbin is completely wound.

      • When the bobbin is ready, place it in the designated place, under the needle, at the bottom of the sewing machine. Leave the end of the thread outside to insert it into the needle.

    2. Thread the sewing machine. The spool of thread located on the top of the sewing machine must be untwisted and attached to the needle. To achieve this, take the end of the thread and pull it through the thread take-up on top of the sewing machine, and then lower the thread down to the presser foot. There should be little numbers and arrows on your sewing machine to show you the order of the thread.

      Take out both threads. Run the scissors under the foot to release the ends of both threads. You should have two ends - one from the thread passing through the needle, and the second from the thread coming from the bottom spool.

      Plug the sewing machine into the outlet and turn it on. Many sewing machines have a built-in light that will help you determine if the machine is running and has electricity. The power button is often located on the right or back of the sewing machine, if there is one at all. Some models of sewing machines do not have such a button and turn on as soon as they are plugged into a power outlet.

      • Also connect a foot pedal to the sewing machine. Place the pedal in a comfortable position under your foot.

      EXPERT ADVICE

      Pattern designer

      Daniela Gutierrez-Diaz is a professional pattern maker and fashion designer at DGpatterns. Creates modern and unique silhouettes suitable for everyday life. Her successful blog, On the Cutting Floor, contains sewing tips and a variety of patterns in PDF format.

      Pattern designer

      Keep your sewing machine clean. Daniela Gutierrez-Diaz, a professional pattern maker and fashion designer, advises: “Take your sewing machine to a specialized sewing machine service center from time to time. so that it can be cleaned there. It is advisable to do this regularly, especially if you use your sewing machine all the time».

      Sewing with a sewing machine

      Select a straight stitch, medium size. Check your manual to see how to do this on your model of sewing machine. On this model, the stitches are set by turning the lower knob on the right side of the machine until it clicks into place. Always set or change the stitch pattern with the needle raised, removing the fabric as it may move the needle.

    • The straight stitch is the most popular stitch in sewing. The next most popular stitch is the zigzag stitch, which is used to finish the edges of the fabric and prevent it from unraveling and fraying.

    Practice on bad material. Choose a plain fabric, not knit, for your first sewing experience. Do not use fabric that is too thick for your first attempts at using a sewing machine. Denim or flannel fabric is very difficult to work with due to their density.

    Place the fabric under the needle. Sew, placing the stitched material to the left of the machine. Laying the fabric to the right may result in uneven stitches.

    Lower your foot. Find the lever on the back or side of the needle that allows you to lower and raise the presser foot.

    • If you lightly tug on the fabric that is pressed down with the presser foot, you will realize that it is being held quite firmly. When you stitch, the sewing machine uses a protractor to move the fabric at the correct speed. Therefore, there is no need to pull the fabric through the sewing machine manually; in fact, if you pull the fabric, it can cause the needle to bend or ruin your project. You can adjust the speed and stitch size using the buttons on the machine.

  1. Keep the ends of both threads loose. For the first few stitches, you will need to hold the ends of both threads to prevent them from getting tangled in the fabric. Once you have stitched a bit, you can release the ends of the threads and use both hands to control the fabric and the sewing machine.

    Press the pedal with your foot. The pedal is responsible for controlling the sewing speed. It's like the gas pedal in a car - the harder you press, the faster the sewing machine will run. At first, press the pedal very slowly and just enough to start the sewing machine.

    • Your sewing machine may have a button that you press with your knee instead of a pedal. In this case, use your knee to press it.
    • You can use the top wheel on the right side of the sewing machine to make it stitch, or you can move the needle by hand.
    • The sewing machine will automatically guide the fabric away from you. You can guide the fabric under the needle in a straight line or at different angles. Practice stitching straight and wavy. The only difference is how you bring the fabric to the needle.
    • Do not push or pull on the fabric that is under the needle. This may cause the fabric to stretch or the needle to break, or the stitch may become caught in the bobbin. If you feel like your sewing machine is not working fast enough, press the pedal harder, adjust the stitch length, or (if necessary) buy a faster sewing machine.

  2. Find the reverse button or lever and try it out. It allows you to change the direction in which you sew, so the fabric flows towards you instead of away from you. Typically this button or lever is held on by a spring, so you will have to hold it to continue stitching in the reverse direction.

    Use the hand wheel to raise the needle to its extreme point. Then raise your paw. The fabric should now be easy to remove. If the thread pulls back when you try to remove the fabric, check the needle position.

    Cut the thread. Many sewing machines have a notch on the pin that holds the presser foot. You can cut the threads by holding them with both hands and running them along the notch. If there is no notch or you want to cut the threads more accurately, then use scissors. Leave the ends of the threads in order to continue sewing the next seam.

  3. Practice sewing seams. Pin two pieces of fabric, right sides together, right at the edge. The seam will be 1.3 cm to 1.5 cm from the edge. You can stitch the fabric in one layer (and may want to do this to reinforce the edge), but since the purpose of most sewing machine work is to join two pieces of fabric together, you will need to get used to sewing multiple layers of material and using pins .

    • The fabric is pinned right sides together so that the seam remains on the wrong side. The front side is the side that will be outer after sewing is finished. On dyed fabric, the brighter side is usually the right side. Some fabrics may not have a facing.
    • Attach pins perpendicular to the line along which the seam will run. You can sew directly over the pins and later easily remove them from the fabric, but doing so may damage the sewing machine, the fabric, or the pins. It is safest to remove the pins as soon as the needle reaches them, since if the needle accidentally hits a pin, it will break and the needle will bend. However, prevent the needle from hitting the heads of the pins.
    • As you follow the fabric, pay attention to where the material moves. The seams can go in different directions, but most sewing projects are trimmed afterwards so that the seams run parallel to the edge. Also, pay attention to the direction of the pattern if your fabric has one, and lay the fabric so that the pattern runs from top to bottom on the right side. For example, floral or animal prints, or stripes or other designs should go in the right direction.
January 18, 2012

The rail works with a presser foot, which must press the fabric against the rail over its entire area with a certain force. For this purpose, the presser foot assembly has an adjustable spring, as well as parts that help lift the presser foot and lower it onto the fabric.

The presser foot can have a movable sole or a swinging foot on a hinge. These paws are convenient because they allow you to easily pass through thickened areas. The foot assembly has the following device.

a - foot knot,
b - kinematic diagram of the foot assembly:

  1. adjusting screw,
  2. spiral spring,
  3. muff appendix,
  4. spring holder,
  5. lever arm,
  6. rod,
  7. rod,
  8. presser foot.

The presser foot 8 is attached with a screw to the rod 7. A spiral spring 2 is placed above the spring holder 4, onto which the adjusting screw presses from above. Under the action of a spring, the presser foot presses on the fabric; the pressing force can be changed with an adjusting screw. If the screw is turned to the right, the spring compresses, creating more pressure from the presser foot on the fabric, and vice versa.

To lift the presser foot, a lever 5 equipped with a cam is attached to the machine head with a hinged screw. If you turn the lever and move its cam under the side extension of clutch 3, the clutch will rise and raise the rod of the foot and the foot.

The transformation of the rotational movement of the main shaft into the oscillatory movement of the shuttle is carried out using the shuttle mechanism.

a - shuttle assembly,
b - kinematic diagram of the shuttle mechanism:

  1. crank,
  2. connecting rod,
  3. swing roller,
  4. fork,
  5. slider,
  6. shuttle shaft,
  7. clip with shuttle.

The movement of the main shaft by means of the connecting rod 2 is converted into the oscillatory movement of the oscillating roller 3. The oscillatory motion from the roller is transmitted to the slider 5 inserted into the fork 4 of the oscillating roller. The slider moves in the fork and drives the shuttle shaft 6. At the left end of the shuttle shaft there is a holder into which the shuttle 7 is inserted. When the oscillatory motion is transmitted from the swinging roller to the shuttle shaft, the angle of rotation of the shaft increases.

The thread take-up mechanism feeds the thread and tightens the stitch. Roller 3 of the thread take-up lever slides in groove 4 of cylindrical cam 5.

a - mechanism unit,
6 - kinematic diagram of the thread take-up mechanism:

  1. main shaft,
  2. lever arm,
  3. video clip,
  4. cam,
  5. ear,
  6. hinge screw.

Lever 2 is secured with a hinge screw 7 in hole 1 of the machine arm, and its arm, which has an eyelet 6 for passing the thread, protrudes from the slot of the front board.

When the cam rotates, the roller slides along the groove and drives the thread take-up lever, which moves up and down at variable speeds and participates in the process of stitch formation - it slowly feeds the thread and moves down, quickly rises up and tightens the stitch.

Questions

  1. Name the working bodies, what is their purpose?
  2. What mechanisms are used in a sewing machine to convert rotary motion into reciprocating motion?

“Service labor”, S.I. Stolyarova, L.V. Domnenkova