maviskw

Pinwheels were the first thing I learned when I began learning about quilting in earnest.

I figured out that some of that bulk in the center can be trimmed out as you go. When you've made the first HST's, trim out the dog ears and maybe a little more, Then when you make the second seam, sewing two HST's together, there is already less bulk in the center.
When I sew the last seam, I match up the seam lines from each HST and nest those seam allowances. If you pin that on both sides of the seam, they will hold. Then I start sewing from one end. When I'm about half way to the center, I take out the pins and take a little peak under to see if the diagonal seams from the HST's are nesting. The pieces can be moved a smidgeon at this point so that they are perfect. Then continue sewing, making sure the needle goes in right at the spot where the seams lines cross. If the seam allowance is covering that seam crossing, you can put a pin in to show you where it is. When it is finished, it's best to open that last seam to further reduce bulk.

I have enjoyed making pinwheels this way, and have made the Disappearing Pinwheel also. (Actually it is a Diminished Pinwheel, as it doesn't go away, it just gets smaller. LOL)