1.Shedding Stroke Adjustment
The shedding stroke of a water jet loom varies with the beating-up stroke, and differs between single-nozzle and double-nozzle looms, as well as plain shedding and dobby shedding systems. Excessively large or small shedding strokes will cause warp breakage and abnormal weft flight. The shedding stroke shall be selected based on fabric specifications, raw material properties, and the configurations of shedding and beating-up mechanisms. It must ensure smooth weft insertion without inducing warp breakage.
For plain shedding mechanisms, the shedding stroke is adjusted by repositioning the shedding pin on the shedding arm when the loom crank angle is at 180°. Moving the shedding pin forward toward the loom front increases the shedding stroke; moving it backward toward the loom rear reduces the stroke.
There are various types of dobby shedding mechanisms. Taking Japan Murata Mx-7 as an example, its shedding stroke is set according to weaving conditions. A smaller shedding stroke facilitates higher loom speed, yet an undersized stroke impedes the flight of the water jet for weft insertion; an oversized stroke readily leads to warp breakage.

2. Shedding Timing Adjustment
The standard shedding timing for plain shedding water jet looms ranges from 350° to 355° for single-nozzle models, and 345° to 355° for double-nozzle models. Incorrect shedding timing results in defective weft insertion or warp breakage. The adjustment procedure for the Tsudakoma ZW302 plain shedding loom is specified below:
a. At the cross-center shed position, the vertical distance from the top of the heald frame to the heald frame guide base shall be 138 mm.
b. At the cross-center shed position (350° crank angle), measure heights H11 and H21 from the tops of the 1st and 2nd heald frames to the guide base respectively.
c. Rotate the handwheel one full revolution and stop at 350°, then measure heights H12 and H22 from the tops of the 1st and 2nd heald frames to the guide base respectively.
d. At 350°, adjust the shedding crank on the right side of the loom to set the height of the 1st heald frame to (H11+H12)/2.
e. At 350°, adjust the shedding crank on the left side of the loom to set the height of the 2nd heald frame to (H21+H22)/2.
f. After completing the above steps, adjust the support feet of all heald frames at 350° to calibrate the height of every heald frame to 138 mm from the guide base.