Sewing mashine keeps knotting my fabric?

Question

Everytime I try to sew a straight seem it knots under the fabric, forcing me to open the whole seam and start over.

any reason why this is happening? A solution?

Answer 1

You also can try multiple straight pins to hold the seam after you hand form it.  About one every half inch or so.  Then when you sew with the machine, there is less chance of 'bunching up' of the fabric as it passes under the shoe prior to stitching.

Also check the needle to be sure there are no nicks on the point.  Use a magnifying glass to make sure it hasn't been damaged and is still smooth to the rounded point.  If it is nicked or rough, it can cut and rip the fabric instead of 'pushing' away the fabric as it penetrates and then cleanly passing through without damaging any fibers.

Answer 2

Most problems like that are connected with the tension in the thread. There are two tension adjustments, and both have to be reset when you change the thickness of your thread.

the tricky one  is the adjustment on the bottom bobbin. There is usually a tiny s***w on the lower bobbin.The s***w is very sensitive. if you move it just a little - like the equivilent 0f one hour on a clock, that can be more than enough.

the way you tell if it is correct is by threading a full bobbin into it, and, holding the thread, let the bobbin hang free on the thread.

if it is adjusted properly, the bobbin will not let the thread run freely. the bobbin will not go down.  but when you give the thread a tiny tug, the bobbin should should 'slip; a few inches each time. Turing the s***w clockwise makes it tighter, anticlockwise makes it looser.

After the lower bobbin is set, rfeset the upper bobbin so that the stiches appear equally tight on the top and bottom of the fabric.