I entered the number 1" in the "finished size" space of the formula, because I needed 1 1/2" half squares.
Sew 1/4" on EACH side of EACH line.
Press, to heat set seams. Cut through the middle horizontally.
Cut through the middle vertically.
Without moving your blocks, cut on the drawn lines in both directions.
This will yield 8 half square triangles. Press to the dark.
Square them up to...hey look at that 1 1/2"!! It worked.
They fit perfectly into my bobbin blocks.