3. Other

 

Head Timing

Head Timing covers these related topics.

	Headup
	Needle Depth
	Hook Timing
	Hook Gap

To make a stitch, the rotary hook point, which holds the bobbin case, passes behind the needle just as the needle is beginning to rise from its lowest point. As the needle rises, a small loop of thread is created behind it as shown in Figure 3-1. When the hook passes behind the needle, it catches the loop and wraps the thread around the bobbin case, capturing the bobbin thread. When the needle pulls the thread above the fabric, a stitch has been made. In order for all this to happen, the needle and rotary hook must be adjusted very carefully.

Figure 3-1

Adjustments become necessary if the needle or presser foot hits a hoop, or if you remove the rotary hook to clear out a birdsnest of thread.

NOTE: The sewing head must be correctly set to the Headup position before you can accurately adjust the other settings. Headup is a factory setting and should not be changed or adjusted unless the Headup encoder has been replaced. Before you attempt any changes to Headup, check with your Melco representative for advice.