I first used it for piecing to see if I could get a better 1/4" seam. Most of us struggle with getting and maintaining an exact 1/4"; I call it a "pressed quarter". I find that if, by measurement with a ruler, I stitch an exact 1/4" from the edge of my fabric, the resulting seam allowance seems a little too big after pressing. So, when stitching a "perfect" 1/4", my 12" block may be 11-5/8" or 11-3/4", depending on how many seams were involved. That's what seems to happen to me when I use a 1/4" foot.
So I'm one of the radicals who like to sew with a non-1/4" foot and move needle position to get my seam allowance where I want it. When I teach piecing classes, I find about half the class likes the 1/4" foot and half don't, usually because it makes the seam allowance too big for them. My personal feeling is that it has a lot to do with your vision and how you sight down the side of your foot.
How I figure out where to move my needle for a perfect "pressed quarter"-inch seam: I rotary cut three strips of fabric 1-1/2" x 6" each and sew them together, using what I think is an accurate 1/4" seam, side-by-side (in other words, on the long edges -- if this is hard to visualize, don't worry, there are pictures below). After pressing, the resulting piece should measure 3-1/2" wide by 6" long if that seam allowance is accurate. The sewn center strip should measure 1" across. If the piece does not measure 3-1/2" exactly, then my seam is not accurate. I will then repeat this exercise, moving my needle position to make the seam allowance either wider or narrower, depending on the results of the first test strips. When I am trying out a new machine or a new presser foot, this is one of the first things I do. I'll keep making these little test strip sets until I figure out exactly where I should be sewing. Once I've got it, I write it down in the little notebook that I am keeping for that particular machine.
Yes, I make a little notebook for every machine I sew on. I sew on too many machines to ever remember tensions, needle positions, width of decorative stitches -- you know, all those little details. As I switch back and forth between machines, all I have to do is look in my notebook. That's a lot easier than conducting experiments over and over and over.....
Here are the results of my piecing with the laser guide:
Tomorrow I'll show you a couple of other cool things you can do with the laser guide!
Brother has provided me with the DreamWeaverTM XE, but all opinions expressed are entirely my own....