marciacp

I didn't take time to read all the responses, but my 2 cents is
that I had this happen to me way back about 30 years ago
when I started quilting. I ended up re-cutting my strips and
what I learned is that the secret to a perfect lone star is in the cutting - not the piecing. When you make your strip sets,
you have to cut each strip with no wobble or curve. That means that you have to cut one or two strips, then place your
ruler on the previously cut line and trim a sliver off to give you a straight edge before you cut the next two or three strips. It is amazing how much one can get 'off' on making the strips straight, even though you are using a mat and cutter.

Then, when you sew your strips into sets, they have to be staggered on one end. I don't know why that matters, but it does. Then, if your strip sets have a bow in them, even a slight one, the diamonds will be off.

Finally, it is very important to cut each set with a true angle,
whether it be 45 or 60 degree angle, it must be true. Again,
after cutting two diamonds, you need to straighten the cut edge as described above, before cutting the next two, to make sure the diamonds are straight and have no bow or wobble.

I know this is long, and perhaps hard to understand, but if you follow these cutting steps, your diamonds will match perfectly. Oh, one more things is to never iron your strips sets, or your diamonds, but 'press' them with a dry iron,
which means to just put your iron on top of the sets and leave it there a few seconds - never iron back and forth because it will distort the bias.

This may be more confusing than helpful, but I have successfully made several loan stars after my fiasco, just
by following these methods of cutting and pressing.
Have a Great Day!
Marcia