Singer Merritt 2404 Instruction Book page 31

Needle Thread Tension
Having selected the correct needle and thread com-
bination for the fabric being used, it may be necessary
to adjust the tension of the sewing machine to insure
a well-balanced stitch.
A well-balanced stitch is produced when the top and
under thread appear the same on the fabrico
Your machine has an adlustable top tension control
system. This control exerts tension on the threads as
they pass through the machine to form a stitch.
• Too much tension
will produce a tight stitch which
will cause puckered .searns,
• Too IiUle tension
will produce a loose stitch.
When an even amount ot tension is exerted on both
threads, a smooth even stitch known as a balanced
stitch, is produced.
Tension Test
Tohelp understand the effect ot tension on fabric and
thread, try this simple test:
• Take two pieces of a medium weight woven fabric
in a solid Iight coloür about 15cm (6 inches) long.
• Place a 2020 size 14 needle in the machine.
• Thread the top ot your machine with a polyester or
cotton dark colou r thread and use a Iighter colou r
thread ot the same fibre and síze in the bobbin.
• Select straight stitch.
• Seam the two pieces of fabric together starting with
the top tension control at
1.
Then as you sew, slowly
turn.íhe tension control from
1
through
9.
• Sew another row turning the dial back to
1.
Vou
should have a balanced stitch on each row mid-way
between the start and finish in each case.
• The different coloured threads will help you to see
the effect that the tension has on the top and bottom
threads.
Now that you have observed the effects of tension,
we suggest that you perform a similar test on a scrap
ot fabric you plan to use, being sure to duplicate the
number ot thicknesses of your garment.
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