The red knob adjusts the stitch length. Loosen the knob, then slide it to lengthen the stitch. It should be between 2 1/2 -- 3 1/2 for most applications. There's a presser foot tension on top, above the needle area. If the presser foot lever is loose when you lift it, that can be tightened. It looks like a metal circle with a screwdriver slot.
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