sewing machine ii 

parts of a sewing machine

1. bobbin winder- holds bobbin while putting thread on it
2. feed dog- moves fabric along under presser foot
3. hand wheel, allows the worker to lift and lower the needle by hand
4. needle clamp- holds needle in place
5. presser foot- holds fabric in place while stitching
6. presser foot lever- raises and lowers the presser foot
7. reverse button- allows the machine to perform backstitch
8. spool pin- holds the top thread
9. stitch length control-adjusts length of stitches
   10. stitch pattern control- allows the selection of stitches
   11. stop motion screw- when loosened it stops movement of the needle.
   12. take up lever- allow upper thread to move and down
   13. tension disc- controls tension of the thread
   14. thread guide-directs thread from the spool pin to the needle
   15. throat plate-covers are around feed dog

common machine faults

1. stitches not interlocking - needle inserted backwards
2. fabric not moving when stitching - fabric is too thick or beginning too close to edge
3. thread breaking - tension too tight or needle is incorrectly inserted
4. missing stitches - needle is bent or material is being pulled
5. loops on under side - loose top thread
6. loops on top side - loose bobbin thread or loose tension
7. fabric puckering - tension too tight or blunt needle
8. needle not moving - stop motion screw is not set for motion
9. needle breaking - loose presser foot or loose needle.