JUKI MEB-3200 Engineer's Manual page 53

Adjustment Procedures
1. Adjust the height of top end 1 of the clamp at the time of lowering to the
material which is actually sewn, and adjust the height rather lower in the
range where the top end does not come in contact with the material. Then
the needle thread can be easily rolled in.
(When lowering needle thread clamp section 2, do it after lowering presser
5 first.)
There are two places of adjustment.
™ Two setscrews 3 : These are used for height adjustment. (For the
normal adjustment)
™ Two setscrews 7 : The lateral direction can be simultaneously adjusted.
These are used for fine adjustment.
(Caution) For the long thread trimming type, there is a case where clearance
A between top end 1 of the clamp and knife cover 4 is less than 1
mm since the position of the top face of knife cover 4 is higher.
2. Adjust the lateral position of top end 1 of the clamp to the center of the
needle at first and assemble the clamp. Then adjust it while confirming both
holding and sewing in accordance with the sewing data to actually sew.
(When sewing the straight bartack, adjust top end 1 of the clamp in terms
of the center of the needle to the right side.)
There are two places of adjustment.
™ Two setscrews 6 : These are for the device. The whole device can be
laterally adjusted.
™ Two setscrews 7 : The longitudinal direction can be simultaneously
adjusted. These are used for fine adjustment.
(Caution) 1. When adjusting laterally, make sure of clearance D between
presser arm, left !0 and clamp cylinder 9, and clearance C
between presser foot, right 8 and setscrew 7 when the
feed moves forward. (There should be a clearance at C and
D.)
2. In case the eyelet presser foot (short thread trimming type
is standard) is used when installing the needle thread clamp
after the set-up of the machine, check whether oblique work
B is performed on presser foot, right 8.
When the right blade type of needle thread trimming knife
is installed, replace the knife with the thread trimming knife
J. The length of remaining needle thread becomes short
and there is a case where adjustment cannot be performed.
In this case, add the oblique work. For the temporary
remedy, slightly delay the lowering timing with memory
switch No. 67.
3. The initial setting of memory switch No. 66 (number of stitches of needle
thread clamp open) is 5 stitches.
Increase the setting so as to stabilize the rolling at the sewing start while
paying attention to the items described below :
1) Release needle thread before the the rotary (eyelet) section of stitches.
When sewing length is short, or lengthwise guide !2 is adjusted to the front, set the number of stitches of clamp open so
2)
that the clamp lifts before top end 1 of the clamp interferes with the guide.
(Caution) When number of stitches of clamp open is increased, sewing length is shortened, or lengthwise guide !2 is
re-adjusted to the front, make sure of clearance E between top end 1 of the clamp and lengthwise guide !2 when
the feed moves forward. (There should be a clearance.)
4. When installing the needle thread clamp unit on the sewing machine which is not equipped with "needle thread haul two-step
function" (without solenoid valve No. 10), take care of the points below. (Perform the same when the optional parts are
attached.)
1) Change the top end 1 of clamp to the screw hole on the right side B (detach it from needle), and adjust clearance F
between the clamp and the thread tension disk setscrew to 1.5 to 2 mm for the use.
2) Increase the needle thread tension compensation (data No. 53) to shorten the length of remaining needle thread.
However, when the length is too short, defective clamp will be caused.
(Caution) Do not perform "(22) Adjusting the length of remaining needle thread". Stitch skipping at the start of sewing
will be caused.
5. When ROM No. of the sewing machine is not 011* (007A to F), it is necessary to change the ROM. (/ 007G)
6. When the needle thread trimming knife of the sewing machine is Part No. 14050009, replace it with Part No. 32023319.
(Even in case of Part No. 32023301, it is recommended to replace it with Part No. 32023319 in order to stabilize the length
of remaining needle thread.
Results of Improper Adjustment
™ Needle thread may not be completely
sewn in if the sewing length is short or
the like even when adjusting the
position of the clamp or various setting.
(Reference)
When the length of remaining needle
thread is not short enough by the
adjustment described in the Instruction
Manual, perform the change of setting of
either one or both of the momery switches
described below :
The value in ( ) parentheses is the standard
one to change the setting.
™ No. 86 (Needle thread trimming ON,
lengthwise traveling amount) / ( 2 to
5)
™ No. 74 (Jump feed speed of thread
trimming of lengthwise axis) / (1500)
(Caution)
1. When the needle thread clamp
2. When the clearance (dimension
49
− −
device is installed after set-up of
the machine for the long thread
trimming, if the needle (upper)
thread trimming knife described
in the Instruction Manual is
14050009, the adjustment may
not be performed since the
length of remaining needle
thread becomes short.
F : 1.5 to 2 mm) between the
optional needle thread guide
setscrew and needle clamp
screw and top end of the clamp
1 is not obtained, the needle
thread guide setscrew comes in
contact with the needle clamp
screw, and breakage of the
components will result.