I used to do the same thing, getting frustrated with any block that had to have exact 1/4" seams. I realized my 1/4" foot jiggles when I sew. It has a guide and I think that causes it to move when the presser foot is down to a fat 1/4 inch. I switched to masking tape at 1/4" as a guide on the sewing bed. I have a simple machine and cannot adjust the needle as much, it is either in the center or far to the left. Also, I started looking for blocks that didn't require an exact end measurement. Like the Disappearing 9 Patch, it can be cut down and squared to any size as long as it is cut the same on each block. It sure makes sewing and quilting so much more fun.