I do what Quilt-till-you-wilt does. Set my needle to the 1/4" mark and even then you have the possibility of veering off a bit. I also like to tape a credit card or two (stacked) to be 1/4" to the right of the needle then keep the edge of the fabric up against the card(s). Along with all of this, I still always use the same machine for all the blocks. I've even made my blocks a bit larger so I can trim them down to be the same finished size.....depending on the pattern of the block.