④-1 Pressure check of sub-nozzle
It depends on the old and new looms and the type of sub-nozzle.
Basically, the sub nozzle should be set above the pressure of the main nozzle.
When it comes to new looms, there are many cases where main = sub,
With older looms, it may be necessary to set the pressure of the main nozzle to +0.1 to 0.2Mpa.
④-2 Drum pin timing check
You need to check the timing of the drum pin opening.
Basically, it is -20 ° from the timing when the main nozzle ejects (in the case of Toyota Industries).
The timing of this pin opening does not fluctuate very much,
but if the main nozzle or tandem nozzle has a strong breeze, or if the thread is thin, the timing may be delayed.
This is because a thin thread may get caught in a breeze and come out of the main nozzle before the air is ejected from the main nozzle.
The easiest way to check is to look at the value of the balloon sensor (the sensor next to the drum pin).
If only the pin open timing is changed and the To and T1 values change, it means that the thread is on the breeze.