Kenmore 148.12400 Sewing Machine Instruction Manual.
Includes:
Threading the machine.
Bobbin winding.
Adjusting thread tension.
Changing needle.
Removing and replacing the bobbin case.
Stitch length and width control.
Stitch pattern selector.
Adjust presser foot pressure.
Feed dog control.
Zipper insertion.
Using feet and attachments.
Cleaning the feed dogs and shuttle.
Replacing the light bulb.
Oiling underside.
Cleaning.
Much more!
PDF download
43 page instruction – owners manual.
Kenmore models:
1240
148.12400
Kenmore 148.12400 Sewing Machine Instruction Manual
Top Tension Control
Probably the most important control on your machine is this one that
regulates your top thread tension. It consists of discs between which
the thread passes. The pressure on these discs is regulated by turning
the dial on the front of the control. The higher the number, the tighter
the tension.
There are many reasons for having to reset your tension. The best
tension for one fabric may not be correct for another. The required
tension depends upon the stiffness of the fabric, the thickness of the
fabric, the number of layers of fabric being sewn, as well as the type
of stitch you are making.
It is best to test the stitching on a scrap of the fabric you are using before starting to make a garment.
To check the thread tension balance
Be sure to use mercerized thread of the same size on the top and on
the bobbin, and a sharp, correctly sized needle for the fabric you are
sewing. Begin with a full bobbin. Set the stitch length for about 12
stitches per inch.
Fold a 6″ square of fabric in half diagonally, forming a triangle.
Make a line of stitching 1/2″ in from the fold.
a. If the seam is puckered – both tensions are too tight.
b. When the bottom thread lays on the fabric – tighten the upper thread tension, and repeat the test. See Fig. 3, Page 11.
c. If the top thread lays on the fabric – loosen the upper thread tension, and repeat the test. See Fig. 2, Page 11.
Grasp the stitching and pull with a snap to make the thread break.
a. If both threads break – tensions are balanced.
b. When neither thread breaks – both tensions are too loose.
c. If the upper thread breaks – loosen top tension.
d. If the lower thread breaks – tighten top tension.
Both threads do not have to break at the same place, but they should break on the same snap.
It is necessary to reduce the upper thread tension somewhat when zigzag
stitching. The wider the stitch, the less tension that is needed. This
is particularly important when making designs. It is not desirable to
have any of the bottom threads visible on the right side of the fabric
when satin stitching.
