Cut two 7" squares from your pinwheel fabric that will be the largest pieces in the block. Cut one 7 1/2 " square from each of the other two fabrics.
Cut the 7" squares in half on the diagonal once. You will have four triangles total.
Layer the other two fabrics right sides together and cut them on the diagonal twice. This will give you four sets of triangles. Carefully carry these to your machine and stitch them into units along the short side of the triangles.
Be careful to sew them all the same way with the same color on top if you want them to spin the same direction!
Then layer the units you have made on top of the larger triangles and sew along the long side of the triangles.
These units should be squares now and they will need to be trimmed.
Trim them to 6 1/2" with the seams exactly in the corners.
Then decide which way you want them to spin, this way...
Or this way? Just twist the blocks until you like them.
Sew them together like a four patch and pinwheel press the seams on the back so it lays nice and flat.
Now your block should be 12 1/2" and ready to go into a quilt. Have fun sewing!
Or if you like the scrappy version...
(this one is 6 1/2" from Green Tea and Sweet Beans pattern)
Enjoy every stitch!