I use an index card, along with the standard size foot, and move the needle until I can sew on one of the lines, with the edge of the foot along the line directly to the right.

If the needle is unable to fall directly on the line, then I move the needle just to the right, making a scant 1/4". This will allow for the thickness of the thread and fabric folding over. Scant is the goal.

Thanks for the info. It actually does have such a pattern key under quilting, then piecing. It says to use the 1/4 inch foot. It doesn't say to move the needle all the way to the right and so makes too wide a seam in my opinion. So I moved it as far right as it would go and presto, it's perfect. Interesting thing is if I just have it on regular straight stitching and kick it all the way to the right using the exact same foot, the seam allowance is too wide.
It also is preset on 1.8 stitch length. ??? I haven't been stitching that tight. That would be terrible to unsew.
Which, of course, I never have to do. haha

I have a Janome 7700. I don't use a 1/4 inch quilting foot. I use a regular open toe foot. I adjust my needle to the correct position for 1/4 inch from edge of foot and save the setting. From then on all i have to do is select the saved setting and it comes out perfect. I have never been a fan of the 1/4 inch special foot.

I have the Janome 8900. Using the 1/4 foot and the piecing setting, I get a perfect scant 1/4" seam. Like you, I don't care for the 1.8 stitch length, so I bump it up to 2.2, which is four clicks for me. I really don't understand why machine manufacturers use a 1.8 stitch length as the default for piecing. My Brother 6000i does the same.

My old Viking D1 allows me to program my own stitch so since I didn't feel the 1/4" foot gave me the scant 1/4" I wanted I made my old and use the foot with the flange on the right side. Seems to work fine for me. Love my old D1 so much for piecing but its screen is starting to fail so will have to take her in for a new one or if too expensive to replace then find another Viking that can use all the numerous feet I have for it. This Viking machine has been a trooper since I got it back in 2000. Have made all my quilts with it, clothing and even stitched over 8 layers of blue jean fabric. Not too many machines can do that. Don't think I'd want to do it too often though.

This is what works for me, too! Easy peasy! No variables of stretchy fabric, maybe not cut correctly, etc. An index card is terrific and it works!! :thumbup:

I did something similar to the Bonnie Hunter suggestion... I got a standard sewing measuring tape, and cut about 6 inches off, used double sticky tape and taped two layers of it together. Thankfully, I have a front loading bobbin on one machine and a side loader on the other, so I only remove it if I'm doing free motion. Measured 1/4" from my standard needle position and then used the double stick tape to stick it to my machine. Not only did it help with my scant 1/4" but it also helped with the issue of the fabric shifting at the end of the seams.

Also, it helped me a lot to think of the 1/4" not as the "sewing line," but as the "folding/pressing line." So the seam allowance is for where it's actually pressed, the seam itself would have to be just to the right of the folding/pressing line. I would get so frustrated because I'd measure my seam and it would be 1/4", but for some reason my blocks were wonky... It's because I wasn't getting the idea the the 1/4" is where you want to press. That's probably really basic for an experienced sewist, but it totally was a lightbulb moment for me. :)

One of my straight stitch only machines (2) has a compensating foot and I use that but it is a bit bigger than a 1/4". I can use it for either machine. My needles do not move. I am going to try Bonny Hunter's method I just saw. I have tries several methods but, find the fabric will work its way under the stop eventually. It is a problem when I have to open the plate to clean under the feed dogs, I need to split it as Bonny did. It is only necessary for patterns. I make alot of quilts where the scant seam isn't necessary.
I would think after all the quilts I have made I would have it dialed in, but I don't.

I have been using Bonnie's seam guide with my Janome 8900 and having much better success with my 1/4" seams, since I started using it. I set the seam with the guide and the 1/4" foot setting (stitch D95), but I don't use the foot. I just have an old Starbucks card blue taped to my machine for the edge. It works great.

At a meeting at my LQS they were showing new gadgets; The ideal seam guide...not as wallet friendly as Bonnie's but here's a link if you want to check it out.

https://www.ericas.com/quilting/tools/misctools.htm