Singer’s Ultralock 14SH654 thread overlock sewing machine with differential feed is intended for household use, but can sew from light to heavy material, including denim. Various types of stitching can be obtained, including three-thread overlock, three-thread flatlock, three-thread wrapped edge overlock, and four-thread stretch mock safety stitch. Problems with the Singer 14SH654 overlock machine can include needle and thread breaking, stitches skipping and fabric puckering.
Lengthen the stitch length if the fabric doesn’t feed well. Increase your foot pressure on the foot pedal for tough fabrics. The harder you press, the faster the machine will sew. Reduce pressure for lighter fabrics.
Don’t pull on the fabric if the needle keeps breaking. Use a larger needle on heavier fabrics.
Check for tangled or snared thread if the thread breaks. Try to use high quality thread. Take a look at the needle and make sure it’s not blunt or bent. Replace it if it is. Turn the machine off and disconnect it from the power outlet, hold the needle with the flat surface to the back, and insert it into the needle clamp. Then tighten the set screw — right by the needle clamp. Tighten the set screw if the stitches skip or if the needles continues to break.
Loosen thread tension on the Singer 14SH654 by adjusting the tension dials if the fabric puckers. The blue dial adjusts left needle thread tension, the green dial adjusts right needle thread tension, the upper looper thread tension is adjusted with the orange dial and the lower looper thread tension is adjusted with the yellow dial. Check for tangled or caught thread too.