The Sewing Test

Whenever the mechanism has been disturbed, it is necessary to carry out a sewing test to check the stitch quality under all operating conditions.

Preparing For The Test

When carrying out the sewing test it is essential to:

Carrying Out The Test

Once the above conditions have been met, it is necessary to make a preliminary test so that the upper tension can be adjusted to give a balanced stitch. That is when the 2 threads lock around each other in the centre of fabric thickness, so that neither shows on the opposite side. This test should be carried out on a double thickness of medium weight fabric. It is easiest to see the stitches if the top and bottom threads are of different contrasting colours that are also different to the fabric colour. i.e. say green and red threads on a white fabric. It is though VERY important that both threads are of the same type and weight.

Balanced Stitch

Balanced Stitch

On machines that have a graduated top tension adjuster with a numbered dial, it may sometimes be necessary to re-calibrate the dial at this stage. Details of how to do this can be found on the Tension Adjustment page.

Once a good balanced stitch has been achieved, it is usual to produce a test sample across the range of conditions. This involves making a row of stitches at the shortest, mid-length and longest stitch lengths. On zigzag models, each of these would be carried out as a straight stitch, medium width zigzag and wide zigzag. When a machine is not correctly setup, then issues are often more likely to show at wider zigzag widths.

For machines with a 'reverse' feed function, this should be engaged for a few stitches down each run. If the fabric is turned at a slight angle during reverse feeding, it will prevent the reverse stitching from covering the already made forward stitches. NOTE - on some models the reverse stitch length is not the same as the forward stitch length.

Test Piece

Test Piece