would the walking foot solve this?
 

I have made several tshirt quilts, but it has been a few years since I worked on one. I am working on the first of three that I will be making and I am having an issue that I don't recall having before. (maybe I just wasn't paying attention before :) )

I have my blocks cut the same size - I have double and tripled checked. But when I am sewing the bottom block seems to "shrink"

the small pieces (4 to 6 inches) I don't really notice. On the bigger pieces the top blocks ends up hanging over by a good amount by time I am done. To combat that I sew half way and then stop and start at the other end

Now I have 3 big long strips for the top ready to sew together and I don't want to mess with that.

Would the walking foot resolve this issue? (at least make it better)

You could try changing the pressure of your foot to see if that helps.

It sounds like the fabrics are stretching. You can add a row of stay tape to the block and then stitch together. It will help prevent that stretching.

Are you pinning the blocks together before stitching? Are the blocks fused with a backing stabilizer? There are light weight ones that do not add bulk to the project.

There are some tips here that might help. I have used this tape to shorten some knit work shirts. It is nice to work with on these types of fabrics.

https://emmaseabrooke.com/

thanks for your tips.. yes the tshirts have iron on fusible. I will try the pinning and I might change the pressure of my foot - never thought of that

I have in the past used tissue paper, cut in strips about 3", then sew with it on the bottom and the fabrics will slide better.

If it were me having that kind of issue, not only would I break out my walking foot, but I would also pin, pin, pin. I hate frog-sewing, so I have learned to pin anything that may be an issue or might attempt to fight back. I am ruthless with my pins but I never sew over them.

Madamekelly, you just used a term I haven't heard before....what is "frog-sewing?"

“Frog sewing” is using a seam ripper. “Rip it” “Rip it” “Ripit!” Lol.

I made a blouse yesterday, and had to take out 7 (seven) different seams! Some days it does not pay to touch my sewing machines. Lol. I did get the blouse done though.

definitely check the presser foot pressure--with 2 t-shirts and 2 layers of stablizer it's probably having trouble moving through evenly. And also use a walking foot if you have one.