Y seam
 

My y seams seam to pull in at the bottom a little and a small bulge where they all connect. Am I not going far enough out? Or maybe to close to the 1/4 inch space I leave? Thank you

can you show us a photo?

I agree w/Tartan - marking is essential to Y seams. Even then sometimes they get a little 'bunchy' if everything is not in the correct placement. For me - lots of pinning is essential.

Usually the pucker means that the fabric on the bottom is not sewn right to the marching dot, or that the seam allowance has been caught unti the seam on the bottom. This is the clearest and easiest method I have seen on sewing a clean set in seam.

https://youtu.be/-DBztmnqK-M

there is also a method in which you press the seam open, then sew the set in seam all in one go, pivoting right at the seam. But I can’t find a good explanation online.

Thank you so much I will try this today. I may have been catching the main block

I will I think my file is too big I need to downsize it. Photo to come. thank you

Thank you I have never done one before.They n but hopefully I will get it

I've found the key to Y seams (for me) is in carefully folding back the fabric when I'm sewing the final seam. I just eyeball where to start and end, and it's more important not to sew long. If I do that, then I rip a few stitches out, even though I do back tack at the ending point.

when you fold, make sure you line up the other two seams, and make sure you don't have any puckers before you start sewing the third. If you didn't get your other two seams fully to the exact point, you may find that you have a very tiny gap in the stitching on one side - this is fine, if instead you line up the ending of the stitches when this happens, you'll get a pucker.

Also, if I am sewing in small pieces (like insetting a 1.5" square in a corner) I'll cut my square a bit larger and then inset it and trim the block afterwards. I sew the first two peices from the outside to the inner corner, but sew the inset part from the corner to the outer edge (both ways). That way if I don't get the corner exact- I can overlap the peices slightly offset so the corner looks good on the front side. So sometimes that last seam, the edges of the fabric aren't fully lined up, one may be a full 1/4" and the other closer to 1/8". Of course, if I totally miss my mark, I get out the seam ripper.

This video with Edyta Sitar is my favorite on sewing Y seams. Since I've been sewing mine this way, I don't have puckers. This might help in the future.
https://www.youtube.com/watch?v=-DBztmnqK-M