can you draw the block adding a 1/4" seam allowance line, maybe using a different color pencil/pen. then as you sew each round you can lay it on to check the size...
or better still, draw the block on template plastic you can see through to do the same.

Thanks. hadn't considered heavy handed pressing.. who has a good paper foundation pattern for the large log cabin diamond?

Good morning, I only know what I would do. These are lovely blocks and the finished piece will be beautiful. I have made similar blocks and they were always a bit wonky. I simply added a final border to each block which I was then able to trim making them all exactly the same size. Once they are assembled nobody will notice if each is slightly wonky.

Even regular log cabin blocks have a tendency to get wonky. So many seam allowances and fabric give. I'd paper piece these diamond -shaped blocks.

I'm a beginner, so take my suggestion with a grain of salt. (I may be misunderstanding the problem.)

You have four choices, as I see it: You can continue with what you are doing and play like it's fine. You can take them apart and see if you can improve them doing what you've already done, but do it better. You can take them apart and re-do the whole thing by paper piecing it. You can do what mbquiltnana said. If I were taking her advice, I would make a "square up' template (maybe card stock) of my desired finished size. I would remove the black log on the ones that don't meet the desired size and make it larger. Then "square it up" to the desired size.

Given the "logs' are not the same size, and the center is not centered, you probably won't notice a small difference in the black logs. Besides, it's already "wonky" with the uneven logs. As long as the centers are lined up, you probably won't notice anything else.

bkay

Those blocks are beautiful !!

I feel your pain!! I have a pattern for a diamond log cabin but it's paper pieced. In your case, my thoughts are, first starch the living daylights out of your fabric and second, try using slightly 'over-sized' strips (rather than your templates then trim to size after each round. BTW - I'm pretty sure the angle needs to be 60 degrees, not 45 degrees. Hang in there. It will be fabulous when you're finished.

Many quilters tend to be perfectionists. I let that go years ago. I encourage you to do the same. Be kind to yourself.

For whatever it's worth, I found this tutorial online. Maybe it might be of some help - - - -


https://cathymariequilts.com/2016/01...-cabin-blocks/

Another older posting reactivated :D Some "new" info in it though, good!