I adjust the stitch length depending on the batting. I use a longer stitch to quilt something that has a thicker batting in it, shorter stitch for a thinner batting.

If you're using a walking foot and quilting in straight lines I would think the feed dogs should be up.

Glad this question was asked. I've just been using my default setting of 2.5, Even for SITD. So far, so good, but maybe I should do some experimenting.

The Viking has a walking foot you can buy to attach for quilting. In case you have puckers it may be worth the investment. A nice taut sandwich and a walking foot can make a big difference.

I like to use my stitch length at 3.0 when doing straight lines. I use the walking foot. I think it is a good length. When I free motions with the darning foot I try to do about the same length of stitch, in fact I just leave it at that length until I start to piecing again for I use that length to sew the binding on.

While on this subject I've always been curious as to how many stitches per inch is "3.0" or "2.5"? I piece at 2.5 but quilt at 3.0.

If I could see well enought to count them, I would tell you. :-)

I think it is about 11-12

I know, Barb, I need new glasses too! I know what: I'll mark out an inch or even 2 on some fabric, set the stitch length at 3 and count the number of times the needle goes thru the fabric! BRB...OK, I stitched thru and index card with 1/4 lines. 2.5 = 9 1/2 SPI (Stitches Per Inch), 3.0 = 8 SPI & 2 = 12 SPI. There now we know!

I bought some needles that weren't Singer brand and I broke them right and left. Bought Singer brand and have had no more problems. They just didn't clear through the plate where the feed dogs are right.

I know the Viking walking foot is about $100. I just went on eBay to see if I could find one less expensive and I found several for under $50 and they were the Viking brand.