Rainbow Scrap Sampler - Split Pinwheel

I was working on some of the star blocks for my Mai Tai quilt yesterday.  I didn't plan to get back to it again until the weekend.  While checking up on a few blogs though, I found a Tiny Tuesday post by Deb at VTquilter and got an urge to whip up a quick block.  Though the Mai Tai block is 7.5 inches, the triangle subunits are 3.5 and would easily fit together to make a 6.5 inch block.

This one uses two different specialty rulers.  First, the small triangles are cut using the companion angle ruler.  This puts the straight of grain on the outside of the block.  Looking at the triangle above, you can see that the hypotenuse is lined up along the bottom which is on the grain of the fabric.  This will prevent distortion as the block is put together.
From a 2 inch strips of light fabric, cut 4 triangles.  Repeat with the medium fabric.

Then use the easy angle ruler and a 3.5 inch strip of dark blue fabric to cut 4 large triangles with the straight of grain on the outside edges.  In this case you can see that the hypotenuse is on the bias.  That is OK this time as this will be in the middle of the block.

Here are all the necessary pieces:
4 small triangles of light blue
4 small triangles of medium blue
4 large triangles of medium or dark blue

Place the small triangles right side together and sew along the edge that is NOT the hypotenuse.  Make sure that you feed them all through the same way.  I put all the light triangles on the top.   If you sew them with the dark triangles on top, your block will spin the other way (Ask me how I know!)   Repeat for all four subunits.  Making sure that all of your blocks have the light and medium fabrics in the same places.

Gently finger press the small triangles open with the seam going toward the darker fabric.  Stay away from the hypotenuse.  It is on the bias and will stretch like crazy if you are not gentle.  The two small triangles sewn together should be exactly the same size as the big triangle.  Check to be sure.  If all is well, place the big triangle, right sides together on the split triangle and sew along the hypotenuse.  Repeat for each of the four subunits.

Press the block with the seams going toward the solid square.  Pressing away from the pieced subunit will generally reduce bulk in the finished block.

Speaking of reducing bulk, don't forget to remove all three dog-ears.

Arrange the four subunits as shown in the picture.  Notice that the long lines all point to the middle and the large triangles rotate 90 degrees as you go around the block.  The small triangles will appear to form a solid square behind the large pinwheel.

Tada!  Your split pinwheel block should measure 6.5 inches.  Stand back and enjoy your new block.