JUKI MEB-3200 Engineer's Manual page 75

Adjustment Procedures
1. Preparation
Measure the actual thread tension U and D before performing
disassembling or assembling adjustment. Perform the measurement
by setting needle thread tension "60"/ looper thread tension "50" and
using the thread tension gauge or the like.
Needle thread (No. 40)
Looper thread (No. 60)
2. Looper thread active tension
1) In the state that AT thread tension shaft 1 is pressed in the disk
closing direction (in the direction of arrow mark), tighten or loosen AT
thread tension shaft 1 so that length A of the magnet shaft becomes
approximately 10.5 mm and fix the shaft with nut 2.
2) There is a groove where thread passes in AT thread tension shaft
1. This groove is required to adjust it to the direction where thread
passes.
(Caution) Place the cutting edge of the groove to the upper slant
left side and be careful that thread is not bent.
3. Needle thread active tension
1) Press the magnet shaft from the rear of the magnet (in the direction
of arrow mark), and fix thrust collar 5 so that length C of the magnet
shaft becomes 11 mm.
2) Tighten AT thread tension shaft 3 so that clearance B between
thrust collar 5 and the magnet becomes 0.5 mm when the disk is
closed, and fix it with nut 4.
3) Turn OFF the power and make sure that the rising amount of disk is
0.5 mm.
4. Re-setting of the memory switch
(Re-setting procedure)
1) When the set value is larger than the setting "60" (or "50") and U (or
D) is output, add the difference to the value of E7 or E8.
2) When the set value is smaller than the setting "60" (or "50") and U (or
D) is output, deduct the difference from the value of E7 or E8.
(Example) In the case where operation panel setting (No. 40) is "75",
which is the same value as U measured in the step 1. Preparation
when re-measuring needle thread tension :
U = 60, 75 - 60 = 15 Difference of panel set value)
Add "15" to the original value of memory switch "E7".
If the original value of "E7" is "72", set to "72" + "15" = "87".
(Example) In the case where opearation panel setting (No. 60) is "30",
which is the same value as D measured in the step 1. Preparation
when re-measuring looper thread tension :
D = 50, 30 - 50 = -20 (Difference of panel set value)
Deduct "20" from the original value of memory switch "E8".
If the original value of "E8" is "72", set to "72" - "20" = "52".
(Caution) If the original thread tension (U, D) should not have been
measured in the step 1. Preparation, perform the aforementioned
measurement at the time of re-setting using tetoron thread #30,
and setting U = 75g and D = 55g. Note, however, that a few
difference will occur.
Setting on Actual thread
operation panel tension
"60" U
"50" D
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Results of Improper Adjustment
™ If length A of the magnet shaft
is larger than the specified
value, thread tension in terms
of the set value is likely to be
higher, and if the length is
smaller, the thread tension is
likely to be lower.
™ If length C of the magnet shaft
is larger than the specifies
value,thread tension in terms of
the set value is likely to be
lower, and if the length is
smaller, the thread tension is
likely to be higher.
™ If the rising amount of disk is
larger than the specified value,
thread tension in terms of the
set value is smaller, and if the
amount is smaller, the thread
tension is higher.
™ Even if the thread tension
setting is the same, there is a
difference between the finish of
s e w i n g b e f o r e a n d a f t e r
performing disassembling or
assembling adjustment.
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