LeMoyne Star | Tepidly Conquered and Consolidation of Learnings--though subject to change!

 I've written several posts on the LeMoyne Star.  I'll not list them here, but you can search to blog for them, and I've included links to the more important ones. Understand that I'm not an expert.  In fact, because I am not (I'm a hack!),  I can share where I have failed; how I have contemplated that failure; and how I have remediated that failure.  Maybe you too are experiencing failures.  After much experimentation, angst, and number crunching, I have accomplished the following:

1. My blocks now construct at (mostly) ALWAYS (now that I slightly upsize my triangle/corner insets)  1/2" larger--the proper trim size--than finished sizes instead of a the F_💣(fbomb) finished  size. I confess, though, that I don't always achieve perfect squareness. Nothing requires more careful attention than a true and straight seam line in this block.  So make a test block and be aware that seam finish (open/over) may affect your outcomes relative to your seam allowance. You will be tested by your block outcome regarding whether you seam line is truly straight and true.
   
2. I have a perfect understanding of the math involved in constructing the block.
3. I constructed a calculator for others who do not wish to go through my machinations and don't have access to quilting programs (I didn't at first which is why I undertook it). 
4. I created a cut sheet for others using the math in the calculator.
   

Here are my final to date learnings on this #!$#$%^%&& block. (I have Deb Tucker's Rapid Fire Lemoyne Star and highly recommend it.  However, making this the traditional way was a personal challenge for me.) I'm far from expert, but my failures are so close to my memory, and my accomodation of those failures, I want to share those.  I'm sure I'm not the only person who has struggled.

Here are some tips PRIOR to beginning:

1. Marti Michell's Deluxe Corner Trimmer (and marking tool).  No futzing about marking long seam lines....line it up, make a dot and trim the corner(s) so that your piece nestles perfectly with the inside diamond. I just clip the corner that is in the inset seam. 💡 You can also use the markings on your 1/4" foot to guide you without marking. I cannot see the right side of my foot with my gate, so I mark I bought a non gated 1/4" foot.  I don't have to make a mark at all!  A #2 pencil through the hole and get a perfect mark.
   
2. Watch the collection of videos that I have consolidated for you on my Quilt Stuff page. I recommend Shar Jorgenson's method
3. Consider glue basting your seams.  I found this helpful--but I do this typically with my piecing, and always with this block.  I ensure that I am applying glue to the biased edge, covering with straight of grain, and then hitting with the iron to dry.  Glue will stabilize the bias.
4. Use a finer weight thread polyester thread.  I'm using 80wt Wonderfil DecoBob.
5. Make a test block.  Your perfect scant 1/4" seam may need to be scantier and/or more perfect depending on how you choose to finish your seams--but if it is too scanty, you will lose your points.  
6. Upsize your triangle and square insets slightly larger than the pattern (unless pattern has it upsized).  If upsizing, you need to fit the corner and work out, v. lining up to the outside of the block.  If you clip your corner, it will snuggle in just right.