Originally Posted by whatever
Brother CS-6000i- want to get a new machine for xmas but need to learn about the stitches so I don't screw it up this one sounds like a jack hammer when I was doing two layers of fleece........................
Have you tried cleaning your bobbin case? That cured my "jack hammer" and it had nothing to do with the stitch length.
The owner's manual for my (old, zig-zag only) Janome gives the range of stitch lengths you should consider for each type of stitch the machine does, and those ranges are pretty wide for each kind of stitch. The only time it suggests you check stitch length is when you stitches are puckered, then you should shorten the stitch length.
I find that problems with stitches are most often related to the size of your needle, what kind of thread you're using and the type of fabric you are sewing rather than the length of stitch.