Skipped Stitches
A
skipped stitch means the gib hook is not catching the
thread consistently� There are a number of causes for
skipped stitches�
Start with step 1 and stop as soon as the
problem is resolved�
1�
Incorrectly Installed, Bent or Dirty Needle
A bent needle will cause skipped stitches because the
loop is not where the gib hook (
A
) “expects” it to be�
Adhesive residue on the needle will cause the thread to
stick to the needle instead of moving through the eye to
form a loop�
Make sure your needle is installed correctly (p� 32), is
not bent or damaged, and is free of any residue from
sewing adhesive material� Fouled needles may be
cleaned with rubbing alcohol� Bent or damaged needles
must be replaced�
2�
Turning Corners Correctly
You can turn gentle corners while sewing at slow,
consistent speeds� If motion is stopped and a change
of direction is desired, position the needle at its lowest
point, then continue rotation until the needle comes up
1/8 inch� Stop and lift the foot to twist the sewn assembly
and make a direction change� Drop the presser feet and
continue sewing� Follow these directions to avoid badly
tensioned corner stitches and reduce the chance of a
skipped stitch�
3�
Not Enough Foot Pressure
Heavy, dense material like closely woven marine canvas
and sailcloth, or vegetable tanned leather, can make the
withdrawal of the needle from the material difficult.
If the presser foot is being lifted as the needle comes
out of the material, the loop that the needle forms will
be too small�
Increase the downward pressure on the presser foot
by tightening the presser regulating thumbscrew
(p� 25,
39
,
A
)�
55
4�
Burred/Damaged Shuttle Gib Hook or Retaining Ring Cap Spring
A machine bind or needle strike to the shuttle gib hook (
A
) or retaining ring cap spring (
B
) may result in a burr or damage,
which can cause the thread to snag�
Remove any burrs by polishing them with emery paper or a fine file. If badly damaged, replace with a new retaining ring
cap spring (#160311) and/or a new shuttle gib hook (#960122)�
5�
Machine Has Gone Out of Timing
If skipped stitches continue, the machine has probably gone out of timing� The timing is checked by determining the
relationship of the needle to the gib hook point�
To reset the timing on your machine, follow the steps outlined in “Ultrafeed Timing” (p� 45)�
Burred/
Damaged
Area
Burred/Damaged Area
> Retaining Ring Cap Spring
> Shuttle Gib Hook
56
B
A
37 |
Sailrite�com
Ultrafeed
®
LS Guidebook
| 38
