Originally Posted by PatriceJ

find a thin, flat see-through ruler. when you line up the 1/4" line, your stitching should be lined up directly under the line on the ruler. if your stitching line is visible above the line - even if it's poker straight and right along the line, it's more than 1/4". like ... 7/32" ... or maybe 5/16". that teeny bit is just enough to throw off the finished size of your block.

move your needle 1 click to the right, but use the 1/4" foot as you normally do. don't change anything about that. i'll bet they come out the right size.