Objective: Learn the essential sewing vocabulary and MC6650-specific terms so later lessons and the machine's own menus make sense.
Before you sew sellable items, you need a shared language for the machine and the craft. On the Janome MC6650, the needle moves up and down to push the top thread through fabric, where it loops with the bobbin thread beneath the needle plate to form a stitch. The bobbin is the small spool of lower thread sitting in the drop-in bobbin case. The feed dogs are the little metal teeth under the presser foot that grip and move fabric; the presser foot holds fabric against them. The throat plate (needle plate) is the metal plate with guide lines measured from the needle, which you use to keep a consistent seam allowance — the distance between the fabric edge and your stitching line (commonly 1/4" for quilting, 5/8" for garments). A backstitch (reverse) sews a few stitches backward to lock thread so seams don't unravel; the MC6650 has a reverse button and an auto lock-stitch button. On the LCD you select stitches by number: straight stitch, zigzag, buttonhole, and stretch stitches. Stitch length controls how far the fabric advances per stitch; stitch width controls side-to-side needle swing (used in zigzag). Thread tension controls how tightly the top and bobbin threads pull against each other — balanced tension hides the knot inside the fabric layers. Knowing these terms turns the machine's menus and future instructions from confusing jargon into clear steps.
Example: Suppose a pattern says: 'Stitch side seam at 5/8" seam allowance, backstitch at both ends, stitch length 2.5.' On the MC6650 you would: select straight stitch #1 on the LCD, set stitch length to 2.5, align the fabric edge with the 5/8" guide line on the throat plate, lower the presser foot, press the reverse button for 3-4 stitches to backstitch, sew forward along the guide line, then backstitch again at the end to lock it.
Try it: On your MC6650, point to and say aloud each of these: bobbin, feed dogs, presser foot, throat plate guide lines, reverse/backstitch button, and the LCD stitch number display. Then set stitch length to 2.5 and select straight stitch #1, and find the 5/8" line on the throat plate without sewing.