Using Service Manuals
Service manuals are often helpful for specific issues on individual machines, but attempting to learn sewing machine repair by using...
How Stitches Form
Thread is drawn from the top of the machine down through the material and needle plate by a needle. The needle reaches its lowest...
Timing
When a sewing machine forms stitches, it may be described as being in time. When stitches fail to form or skip, the machine is said to...
Set Stop Positions
Oscillating hooks move back and forth from their start/stop positions. With the needle at its lowest position, the point of the hook...
Rotary Hook
Rotary hook rotates twice for each stitch. As the needle moves to its lowest position and rises to "loop lift" (the point where the...
Hook It
There are two types of hooks in sewing machines: Oscillating and Rotary. Below is a picture of a common oscillating hook. Notice its...
Needle Bar Height
The needle bar must be adjusted to the correct height to enable the needle to be positioned for the hook. Loop lift is the position of...
Needle Bar Adjustments
The needle is the most important part on the sewing machine, but the position and movement of the bar to which it connects controls the...
Upper Shaft Balance
The upper and lower shafts of a sewing machine must work perfectly in parallel or the balance of the machine becomes unstable. If the...
Find the Collar
The parabolic adjustment involves properly aligning the cam gear to the upper shaft gear. As the cam gear is turned, the linkage of...
