Sewing machine basics: threading, bobbin, tension and a first seam

To get a sewing machine ready to sew, wind a bobbin, thread the upper thread with the presser foot raised, insert the bobbin and pull its thread up, then set a straight stitch about 2.5 mm long (10 stitches per inch). Test on a double layer of scrap fabric: when the stitches look the same on both sides, the tension is balanced and you are ready for a first seam. Machines differ in the details, so keep the manual next to you; the principles below apply to almost every home machine.

The parts you will use

• Spool pin and thread guides: hold the thread and lead it through the machine.
• Tension dial: sets how firmly the upper thread is held, usually numbered from 0 to 9.
• Take-up lever: the arm that moves up and down above the needle and pulls each stitch tight.
• Presser foot and lever: the foot holds the fabric against the feed dogs, the toothed bars under it that move the fabric forward.
• Needle plate: the metal plate under the foot, engraved with seam guide lines in millimeters or inches.
• Bobbin and bobbin case: hold the lower thread, under the needle plate.
• Handwheel: on the right side; always turn it toward you.
• Stitch selector, stitch length and reverse: choose the stitch, its length, and sew backward to secure seams.

How to wind a bobbin

1. Use the bobbins made for your model. Bobbins that look alike often differ slightly, and the wrong one causes jams.
2. Put the thread on the spool pin, take it through the bobbin-winding guide, and wrap a few turns by hand around the empty bobbin.
3. Push the bobbin onto the winder shaft and lock it into position.
4. Hold the thread end, press the pedal at a steady medium speed for a few seconds, stop and trim the end close to the bobbin.
5. Keep winding until the bobbin is full or the winder stops, then unlock it.

An evenly wound, firm bobbin sews evenly. If the thread looks loose or lumpy, wind a new one.

How to thread the upper thread

1. Raise the presser foot. This opens the tension discs so the thread can slip between them. Threading with the foot down is the most common cause of a tangle under the fabric.
2. Turn the handwheel toward you until the take-up lever is at its highest point.
3. Follow the numbered path printed on the machine: through the top guide, down the channel, around the U-turn and up into the take-up lever. Check that the thread passes through the eye of the lever.
4. Bring the thread down through the guide directly above the needle.
5. Thread the needle from front to back on most machines (some thread from left to right; your manual shows which), and pull out about 15 cm (6 in) of thread.

How to insert the bobbin and bring up its thread

• Drop-in bobbin: place it in the case so the thread unwinds in the direction shown on the diagram near the plate, then guide the thread through the slot.
• Front-loading bobbin: put the bobbin in its case, pull the thread into the tension spring, and click the case into place.

To bring the bobbin thread up, hold the end of the upper thread, turn the handwheel toward you for one full turn, and pull the upper thread gently: a loop of bobbin thread comes up through the plate. Pull both threads under the foot and toward the back.

Choose the needle and stitch length

Change the needle after about 8 hours of sewing, at the start of each new project, or as soon as it skips stitches or makes a thudding sound. The glossary entry on stitch length explains how millimeters and stitches per inch compare.

Check the thread tension

Balanced thread tension means the upper and lower threads lock between the two layers of fabric, so neither shows on the other side. Many machines sew balanced at a middle setting such as 4, but the right number depends on the machine, the thread and the fabric.

Sew a line on a folded scrap, ideally with different colors in the needle and the bobbin, and look at both sides:

• Bobbin thread shows on top: the upper tension is too tight. Turn the dial to a lower number.
• Loops or upper thread lie on the underside: first rethread the upper thread with the presser foot up. If the loops persist, turn the dial to a higher number.
• The fabric puckers along the seam: lower the tension slightly, or shorten the stitch on fine fabric.

Change one number at a time and test again. Leave the bobbin case screw alone unless your manual tells you to adjust it.

Sew your first seam

1. Place two scraps right sides together and pin at right angles to the edge.
2. Line up the raw edges with the 1.5 cm (5/8 in) line on the needle plate, the standard seam allowance for woven fabric.
3. Turn the handwheel to put the needle into the fabric, then lower the presser foot.
4. Hold both thread ends lightly behind the foot for the first few stitches.
5. Sew 4 stitches forward, 4 in reverse, then forward again. This backstitch locks the start of the seam.
6. Sew at a steady speed, watching the edge of the fabric against the guide line rather than the needle. Guide the fabric; do not push or pull it.
7. Pull out each pin before it reaches the foot.
8. At the end, backstitch again, stop with the take-up lever at its highest point, lift the foot, slide the fabric away and cut the threads.
9. Press the seam flat as sewn, then press it open.

When this feels easy, move on to curves and corners in how to sew a straight seam and pivot.

Troubleshooting

Safety and care

Keep your fingers clear of the needle, and switch the machine off before changing the needle or the presser foot. Brush lint out of the bobbin area after every project, and oil the machine only where and when the manual says. Cover it when you are not using it, so dust stays out of the mechanism.