I attended a Marti Michell workshop and she said that the first thing she does when she sits down to quilt is take 3 six and one half inch by 1 1/2 inch strips and sew them together. If the middle strip is 1 inch the seam allowance is correct. She maintains that there are many things that affect the width of the seam besides the machine setting. How are you feeling that day, are your glasses dirty, is you leg hurting so you're not sitting in front of the machine the same as the last time you sewed....and you can add to the list. My instructor at my current BOM did that and it took her about 5 adjustments to get the middle strip to one inch. Those little blocks become the start of a fun little charity quilt while your quilts all have better points and matching seams.

I have the 1/4" foot and still have problems, so your not alone.
Tomorrow will be a better day. Good Luck.
Your quilt will be fine.

This happens to all of us occasionally, no matter how carefully you sew.

Even with a 1/4 inch foot - you will still need to "verify" that you are ending up with what you want. There can be variations from machine to machine.

I use my 1/4" all the time but do have to warch I keep the fabric up to the black ridge--easy to not keep it snug.

If all your blocks are 12 inches, you just put them together as usual. If your blocks are different sizes, you might make them all the smallest size.

QUOTE=LLWinston44;4617725]I canNOT do a 1/4" seam without my foot with a guide on it. Even then sometimes I slip up. If all your blocks are the same size, can't they still be used?[/QUOTE]

For jelly roll strips, I read somewhere that if you use a guide on the left side and put it to 2 1/4" away from your needle your strips will be right every time, because different batches can come in slightly different widths. It only takes a thread or two difference to mess you up.

This sounds like a terrific and easy way of getting everything perfect. Great tip, thank you.

I feel your pain also because this happens to me all the time! Sometimes I rip out. If I see things are off, I use a scant 1/4 on some seams. Sometimes I just fudge. Sometimes I change the whole concept of the pattern to make it "fit" what I have.
I do have a 1/4 inch foot, but it is not correct or I don't sew it correctly or I don't see it correctly. Whatever, I did the measuring from the needle and putting down tape also. That helps as long as the material is CUT correctly, which is another problem for me for whatever reason.
Just do your best. That's all we can do.

I also use a 1/4" foot with a guide, but found that it was still a little generous. On my machine, I can bump the needle over to the right just enough that it won't hit the foot (it's a single hole foot), but will still give me the scant 1/4" seam that I need. This really comes into play when you have several people making blocks....sometimes there's 1/2" difference in the size of a 12" block! It's always good to check the final measurement of your blocks to see if they are finishing as they should.