Is this normal?
 

Hope I can explain this clearly enough so you can visualize. I noticed while sewing yesterday at a medium speed that the fabric slightly jumps up and down as it approaches the sewing machine needle. It has probably always been this way, but wonder if I need to change needles or the tension. Shouldn't the fabric just calmly and smoothly run along? I have a 3 yr. old Janome 6600. THX

I've noticed when we have a throat-plate that accomodates a zig-zag stitch, the fabric behaves differently than with a plate that works only with a straight stitch.

Perhaps change the needle to a smaller needle.

Now I will be watching to see if my fabric dances or glides!!!

Check your feed dogs, are they up? (or down)

I agree - change the needle, but also make sure you are using the correct needle. One that is too small or too large for your fabric will sometimes cause a problem, too. There are also " sharp" needles that have a sharper point than the regular 80/12 that might help with a tightly woven fabric like a batik.

In addition to changing your needle, check for lint build up at the feed dogs. Remove the plate covering the feed dogs, and clean out any build up.

I second using a straight stitch plate when doing straight seams. I think the larger plate for zig-zagging may cause your fabric to jump. And yep! Check your needle size.

This is a good idea!