I make a sandwich with same batting and same fabric then make a test
with same binding fabric and same width. I don't get it right on the edge
but it's pretty close. Otherwise I get a lot of hit and miss then have to
redo it by hand which defeats the whole purpose of sewing the binding
by machine. You might have to adjust the width at which you sew your
binding a little. I like a larger binding on most of my quilts so I cut mine
2.5" and it finishes at 3/8". Or you could cut your binding a little narrower
like 2" and make a test.