with machine quilting small flannel quilt for great nephew. Set stitch size and was perfect on practice fabric, but when I sew the quilt the bottom stitching is either too loose or very tight. Do I need new needle or what is the cause of this problem. I am using straight stitch foot.

Not sure, but do you have a walking foot for your machine.. that would help feed the layers of fabric through and maybe eliminate the bottom stitching problem.

I agree.

Don't really know, but, sometimes when I have tension problems I can clean out the bobbin case, add a drop of oil and my tension problems disappear. Flannel may be causing a lot of lint in the bobbin case so it might be worth a try.

Thanks, I do not have walking foot, I will have to get one Sat. Also, I just cleaned lint out of machine.

Have you tried rethreading your machine? I can't tell you how many times I've learned this lesson.

Quilting foot for sure.

I think the walking foot will help. On a practice square there is just a little fabric, but with a quilt there is weight to pull on your fabric and it can cause problems. Do you have a table to support the weight of the quilt.

Also a lot of basting and/or pinning will hellp keep layers in place. Or spray basting also.

Yes I have dinning room table for my sewing machine.....and I did baste the quilt....make sure thread was threated properly..so it must be the need for walking foot...machine is a Kenmore, so need to go to sews repair shop or mall store

Thanks to everyone for suggestions...