JUKI DDL-9000C-S Series Engineer's Manual page 37

Adjustment Procedure
5) Adjusting the amount of oil in the hook
Tighten (turn clockwise) oil amount adjustment screw ❶ to increase the
amount of oil in the hook, or loosen (turn counterclockwise) to decrease it.
(Caution)
[When using RP hook (hook for dry head) for DDL-9000C-SMS type]
1. Remove hook driving shaft oil wick setscrew ❷ and
attach hook driving shaft stopper screw ❸ (part
number : 11079506) and rubber ring ❹ (part number :
RO036080200).
2. Loosen oil amount adjustment screw ❶ up to the mini-
mum so as to reduce the oil amount in the hook. How-
ever, do not completely stop the oil and be careful not
to allow oil adjustment screw ❶ to come off.
3. Never drain the oil in the oil tank even when RP hook
(hook for dry head) is used.
6) Hook oil adjustment procedures
1. Tighten the hook oil quantity adjusting screw ❶ to obtain the maximum
oil rate and operate the machine for about 30 seconds.
2. Loosen the oil adjusting screw by two turns and check the quantity of oil.
In this case, give 30 seconds of idling to the sewing machine and measure
the quantity of oil at the intervals of 5 seconds (about 35 seconds in total).
3. According to the quantity of oil secured at that time, determine
the amount of turning for the hook oil quantity adjusting screw ❶.
Give 30 seconds of idling to the sewing machine after re-adjust-
ment and measure the quantity of oil at the intervals of 5 seconds.
4. Adjust the screw position in the procedures of 2. to 3. above until
an adequate quantity of oil has been attained.
(Caution) When the hook is replaced or in the case of the head
(including the heads in a new state) not used for a long
time, it takes about 10 to 20 seconds (4,000sti/min) until
the oil begins to appear from the hook.
The machine stays in the state of causing seizure.
Therefore, use the machine after running-in operation at
2,000sti/min or below.
7) Essentials for hook oil adjustments
1. When the quantity of hook oil is adjusted from excessive oiling
condition to reducing condition (loosening the screw), it is pos-
sible to carry out stable adjustments.
2. Check the oil quantity about three times to confirm the stability.
3. If the quantity of oil is too much before adjustments, operate the
machine continuously for about one minute so that the oil attached
to the hook and remaining in the oil path can be flung off completely.
8) Replacement of the hook shaft oil wick
Oil wick ❹ is a consumable item. Periodic replacement is recom-
mended for the stabilization of hook oil quantity.
1. Remove the hook.
2. Remove the set screw ❸.
(Caution) Make sure not to hurt the tip hole of the set screw ❸.
3. Enter a new Oil wick ❹ to the inner part of the set screw ❸ and
then get it around the hook shaft.
Results of Improper Adjustment
◦ When you use an dry hook, buy
and mount the hook driving shaft
stopper screw ❺ and O-ring ❻
that stop the hook oil quantity.
◦ By feeding very much oil, let the
oil prevalent around the hook and
through the lubrication route as a
whole so that the oil path can be
stabilized.
<When the quantity of hook oil is too much>
◦ Too much oil can stain the materi-
als to be sewn.
◦ Oil consumption in the oil tank is
increased.
<When the quantity of hook oil is too less>
◦ The lubrication route tends to be af-
fected easily by factors such as dust.
It is, therefore, necessary to check the
condition of oil quantity periodically.
◦ Under rigorous conditions (operation
at high speed or continuous opera-
tion), pay attention to the possible
occurrence of problems such as hook
seizure and thread breakage by heat.
◦ If a contaminated oil is used, filter
clogging occurs earlier and this can
be a cause of unstable oil quantity.
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