Originally Posted by
Sunnye
Yes, every machine is different as Rodney said.
I struggled with the 1/4 inch for years. I finally wrote down where I had to put the needle to get a 1/4 inch. Then I finally got better at my "art" and realized that it all wasn't me. My machine was finally sent back to the factory for and "overhaul." I got new feed dogs, new needle threader, you-name-it, I got it new. Can't tell you what a difference it made.
If you think you are crazy for not being able to get the 1/4 inch (and in my case a straight line; mine was straight but diagonal), consider that it just may be your machine.
I have always struggled with an accurate quarter inch seam, and I have tried everything listed so far plus numerous different feet. What's made the difference for me is getting a new machine. I find if I set the stitch width to 6, I get a perfect quarter inch. My last machine couldn't go wider than 5. It's taken me a decade to get this worked out!