Motorola HE-8000 I, LH4-B800E Underlay programs, Underlays sewn together, Saw-shape underlay

5. OPERATION

5-4-5. Underlay programs

Four types of underlay patterns are available. These four types can also be combined. Refer to the examples of use to determine which type of underlay to use.

1.Underlays sewn together

•This type of underlay pattern is used for resewing if the knife has operated before the seam has been formed, such as when sewing is complete without the upper thread breaking even though the lower thread has run out. It is particularly useful for sewing up the hole made by the knife beforehand at times when zigzag stitches do not hold properly.

•The pile of fluffy fabrics is pressed down before sewing, so that the buttonhole finish looks more attractive.

2.Saw-shape underlay

•This type of underlay is useful for stretch materials to prevent them from stretching.

•It is useful for preventing dimples from forming during bar tacking. Radial-type buttonholes are useful for preventing dimples.

•It is also useful for strengthening the buttonholes to stop the seam from unravelling, which can often happen with materials with coarse weaves.

3.Rectangle underlay

•This type of underlay is useful for stretch materials to prevent them from stretching.

•This is effective in preventing seams from unravelling in materials which appear not to have a very coarse weave. It also serves to reinforce the buttonhole.

•If the seam is hidden and the seam width seems small, you can sew 2 - 3 rectangle underlays to make the material look more voluminous.

•Underlays such as (1) to (9) in the illustration can be sewn in slightly different positions by changing the setting value for parameter No. 50 (underlay offset) so that the seam does not become too stiff and to further increase the feeling of volume.

4.Zigzag underlay stitch

•This is particularly effective in preventing seams from unravelling in materials which appear not to

have a very coarse weave. It also serves to reinforce the buttonhole.

(If parameter No. 58 - Zigzag width [Dimension A in the illustration] is set to about 0.4 mm, the zigzag underlay stitches will be even stronger than other underlay stitches.)

*If parameter No. 58 is set after saw-shaped underlay stitches or rectangle underlay stitches have been set, zigzag underlay stitches will only be sewn for the first cycle of underlay stitching.)

NOTE:

When sewing underlays, the number of bar tacking stitches will increase, so that thread breakages or broken needles may occur. To avoid such problems, reduce the number of underlays or drop the sewing speed.

*When underlays are sewn together, the order of sewing is underlays sewn together → saw-shape underlays → rectangle underlays.