I think that the net net to get a piecing which measures the correct dimension and a block which is the correct dimension is consistency! Developing consistency and then maintaining it within the constraints of your project fabric and thread regardless of what foot you use or if you burn oil or herbs or a doll stuck with pins - and I have thought about all that!!! (Thank heavens for MTS telling me about Sally Collins who saved my sanity.)

Every fabric and thread choice will change the dimension.

The little black 1/4" foot guide (unless you push the fabric into it or hold off from it a tad - which is no different than any other bumper or guide or marking system)will be as consistent as any other guide. Your own variations in running the material through, plus how you set the piece (iron-set seam, iron inside out, iron right side with starch - or whatever method you prefer and use consistently) will create either a consistency or a variation.

Ralph Waldo Emerson said "Consistency is the hobgoblin of little minds" but then he never had to quilt!!!

My Bernina lets me move my needle to the right and I just do that one time and then I can use my guide and have a scant 1/4 inch. Works really well - that is if I sew straight. But I can't blame that on the foot!

I purchased the 1/4 foot with the guide. However what I notice is that because the foot is not as wide on the right side it does not cover the feeddogs like the left side does and it tends not to feed equally therefore I feel I am fighting the machine and fabric. I am thinking about getting a 1/4 foot that is equally wide on each side at the back and 1/4 at the front hoping it will correct the problem.

I read a topic on here about adjusting pressure but my machine does not allow me to do this.

Anyone else have an Idea? I don't want to spend more money if it won't fix the problem.

I had same prob wIth Janome foot - put on F foot with 7 needle poisition and go by marking on the metal plate. That way I get qtr inch and both feed dogs

I have given a lot of thought to this and decided that the scant would be different based on the weight of the fabric. Some of my fabrics are thinner and lay different when pressed. Different weight fabrics, different seam width. I have moved my needle over one click and found my seam was still off. Wish this was easy! :-(

Perfect Piecing Seam Guide from Perkins Dry goods. Best 5.00 I ever spent.

I'm glad I'm not the only one who seems to have this problem. I'll try this and see how it works before I purchase another foot.

I have the guide and after a few times of stitching with it, I just love it. It was weird at first but with a little practice I won't sew without it.

I use the "scant" 1/4" because I feel that when you press to one side, that is where the "scant" plays a part. I seem to lose some of the 1/4". It is easier to trim the block.

How come none of those expensive quilting books mentioned this. Might explain why my blocks don't come out the right size all the time. I will try this in the morning.