Lock stitches, trims and stops

A lock, or tie, is a few small stitches where stitching starts (the tie-in) or ends (the tie-off). It stops the thread from pulling out when the machine cuts it or jumps to the next part. StitchCraft adds the locks an element’s settings call for, and a trim or a stop after an element that sets trim_after or stop_after.

Where locks go

The needle sews straight on from one part of a design to the next when nothing separates them: the same thread, and a gap of at most 3 mm (the collapse length) or the element’s min_jump_stitch_length_mm. There it sews no locks. Anywhere else the stitching ends with a tie-off, the needle jumps, and the next part starts with a tie-in.

• ties chooses which ends get a lock. By default both ends do. It can also choose the start or the end alone, or neither.
• force_lock_stitches adds the tie-off at the end of each part, even where the next part is close enough to sew on.
• Manual stitch gets locks only when force_lock_stitches is set, because its needle points are placed by hand.

Lock shapes

lock_start and lock_end choose the shape at each end. The default, the half stitch, goes forth and back twice over half the first stitch, and the stitching covers it. back_forth does the same over steps of lock_start_scale_mm and lock_end_scale_mm, 0.7 mm by default.

The drawn shapes are larger. lock_start_scale_percent and lock_end_scale_percent size them, 100 % by default. Each picture shows an 8 mm line with the shape at both ends:

arrow	bowtie	cross	star

simple	triangle	zigzag	half_stitch

The shapes are StitchCraft’s own designs, sized to hide under the stitching they secure. A file from Ink/Stitch that names a shape gets StitchCraft’s shape of that name.

A custom lock (custom) is your own steps, written in lock_custom_start and lock_custom_end as numbers in sizes of the scale in millimetres. Positive steps go into the stitching. 1 -1 1 -1 goes forth and back twice, as back_forth does. The steps follow the stitching round its corners.

Every lock stitch is at least 0.2 mm long, to keep the needle out of the hole it has just left. StitchCraft lengthens a step or enlarges a drawn lock that would be smaller, and SC-W0502 says so.

Trims and stops

• trim_after cuts the thread after the element, with a tie-off before the cut.
• stop_after pauses the machine after the element, while you place appliqué fabric or check the work. When the design has a stop position, the frame moves there before each stop.

A PES file marks a trim on the jump after it. Some Brother machines are reported to ignore that mark, and test sheet TS-02 checks what the reference machine does. DST has no trim command. StitchCraft writes a trim there as 3 short jumps that end where they started, and a DST machine set to cut at 3 jumps in a row cuts there. The machine formats design says how each format records a trim.

Parameters

Common parameters lists each of these settings with its range and default.