TM 10-3530-207-14
Table 3-1. Operator troubleshooting - continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
DARNING SEWING MACHINE
Step 5. Check machine settings.
a.
Machine settings may be wrong or they have accidentally changed during mending.
Check machine settings and make sure they are correct by following operating
instructions of para. 2-12i.
b.
Replace broken needle with new needle of correct size, class, and variety (paras
. 2-
12a and 2-12b).
25.
NEEDLE THREAD BREAKS.
Step 1. Check that needle is not installed backward or needle eye is not threaded backward.
Check that threading is correct.
a.
If needle is installed backward, reinstall needle correctly in needle bar clamp (para.
2-12b).
b.
Needle should be threaded from left to right through the needle eye and machine
must be threaded correctly (para. 2-12c).
Step 2. Check that thread is not caught in spool notch or wrapped around spool spindle.
Smooth notch in spool or change spools as necessary.
Step 3. Check for rough or burred places on thread guides, presser foot, and latch guard hole.
If rough or burred places are found, notify next higher level of maintenance.
Step 4. Check for bent needle, blunted needle point or rough/burred needle eye.
Discard bent or blunted needle and replace with a new needle of correct size, class,
and variety (paras. 2-12a and 2-12b).
Step 5. Check that needle is all the way up in needle bar and the needle bar clamp is tight.
Insert needle all the way up into needlebar and tighten needle bar clamp (para. 2-
12b).
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