plate, the feed dog height is correct; if the valley is not level,
b. Loosen the feed fork screw (figure 4-6 [E], table 4-1, foldout at the end of this chapter), push the feed bar (figure 4-6 [F]) up or down as necessary to obtain the proper feed dog height, and tighten the screw. This completes this timing point.
To properly time this class of sewing machine, you must center the feeding action before the hook is timed.
NOTE: Ensure the needlebar rock frame hinge stud and the needlebar rock frame guide bracket are tight to prevent the needle from wandering from side to side or fore and aft.
a. Depress the plunger (figure 4-1 [H]), and turn the balance wheel toward the operator until the plunger drops; keep turning the balance wheel until it stops. This sets the maximum stitch length at 3 1/2 SPI.
b. Turn the balance wheel toward the operator and observe the movement of the feed dogs. If the feed dogs operate properly, consider them properly centered and continue to step 2. If the feed dogs strike the front or the back of the throat plate, proceed as follows:
(1) Loosen the feed-driving crank pinch screw (figure 4-6 [G]), and push the feed dog away from the point where it strikes; then retighten the feed-driving crank pinch screw.
(2) Turn the balance wheel toward the operator until the needle is at its lowest point and observe the relationship of the needle and the hole in the throat plate. If the needle is near the front of the hole but not touching it, proceed to step 4. If the needle needs to be centered, proceed to step 3.
(3) If the needle and throat hole are not properly aligned, loosen the needlebar rock frame rockshaft connection crank pinch screw (figure 4-7 [A], table 4-2, foldout at the end of this chapter) and align the needlebar in the hole of the throat plate; then retighten the screw.
(4) Turn the balance wheel toward the operator and observe the operation of the alternating pressers. If the front foot does not strike the back foot, then the feeding action can be considered to be centered.
4. Timing the hook and the needlebar
In this timing sequence, we will consider that the machine has no timing marks on the needlebar.
a. Remove the throat plate, the feed dog, and the presser feet.
b. Turn the balance wheel toward the operator until the needle is raised three-sixteenths of an inch from its lowest point.
If the point of the hook is in line with the center of the needle, one-sixteenth of an inch above the eye of the needle, and as near to the needle as possible without touching it, then the hook and needlebar can be considered to be in time. If not, proceed to the following steps:
(1) Loosen the pinch screw (figure 4-7 [A]) and move the needlebar (figure 4-7 [B]) to obtain the proper height, as shown in figure 4-7 (C); then retighten the needlebar clamp pinch screw.
(2) Tilt the sewing machine back; loosen the hook saddle pinch screw (figure 4-6 [A]), the hook saddle adjusting screw (figure 4-6 [B]), and the hook drive gear setscrews and spline screws (figure 4-6 [C] and [D]).
(3) Move the hook saddle (figure 4-6 [U]) to the right and the hook drive gear to the left until they are disengaged.
(4) Turn the balance wheel toward the operator until the needle is raised three-sixteenths of an inch from its lowest point.
(5) With the point of the hook in the 7 o'clock position, engage the hook pinion gear and the hook drive gear to align the hook point with the needle. As you engage the hook, it will rotate clockwise, advancing toward the needle until the hook point is centered on the needle. The hook point should be as near as possible to the needle without touching it.
NOTE: The hook guard maybe out of adjustment and prevent the hook from being adjusted close enough to the needle; if this is the case, bend the hook guard out of the way enough to allow proper adjustment. See step 8.
(6) Tighten the hook saddle pinch screw and the hook drive gear setscrews and spline screws.
(7) Turn the balance wheel toward the operator to ensure the hook does not strike the needle.Continue Reading