Not that I knew of!  But could I come up with one? You betcha :c)  And along with it, I thought it would be a good opporunity to include my method of making these little gems.

This is one of those units that has always caused problems for me.  It starts with an odd sized square in the center, due to the 'on point' measurement. Any time that a pattern told me to make these, the corner triangles always ended up being too small and looked wonky.  I tried every ruler out there (including some that cost over $20) to try to get these to come out RIGHT. I appreciate the efforts of some of the rulers, but they had issues, like....if you sew strips or rectangles to all 4 sides of your center square, and then trim them off, you have to trim ONE side at a time, and it was easy to lose the correct angles of the corners. It also put all 4 outside edges of your unit on the bias instead of the straight of grain, and you lost SO much fabric in the trimming.

If you cut your strips and rectangles with the bias edge on the outside first, to square them up to be on the straight of grain, you had the hassle of cutting bias strips to begin with, and on top of that you STILL lose all the fabric you cut off. GRRRR! So here I am. And this is what I have discovered works for me.

I start by cutting  my triangles bigger than I need them to be. For instance, if a pattern says your triangle should be cut from a 2 3/8" square, I add about 1/2" to that measurement. This makes each triangle about 1/4" bigger than is called for. Plenty of fudge room! You can even round it UP a bit if you want to because you are going to trim the block down later, and lose just a smidge in the squaring process. (But it's a straight of grain smidge!)

All of my previous mysteries have used specialty rulers, and this is one I use time and time and time again because it works with the sizes of scrap strips I keep on hand.  If you don't have an easy angle ruler, get one!

According to the chart below, cut your center squares, and your corresponding corner triangles. The Easy Angle cutting measurement is the first size given for the corners. If you do not have the easy angle, The regular rotary cutting measurement is given in the column next to the Easy Angle sizes.

   

The first thing I do is take the center square, and crease it in half with my fingers.  I use this crease to align the point of the triangle at the center of the square. Having your triangle points in the right place is important with this unit!  Sew triangles to one side of the square, but do not press yet. You'll press out your crease, and you need that for placing the triangle on the opposite side. Sew the second triangles on the opposite side using the crease to center the point.

Look at the first picture above. Can you see how I have trimmed off the large dog ears to be even with the sides of the center square? After the second triangle is sewn opposite the first, press the units open and trim the dog ears even with the sides of the squares. Press seams towards the triangles you just added.

Adding the 3rd triangle: Because I use the easy angle to cut my triangles, I've got a notched edge that just FITS the pressed out triangles!  This makes positioning triangle 3 and triangle 4 extra easy.

It is also REALLY important to keep your seam allowance at a proper 1/4" so that your center square finishes to the right size. If your seam is too big, your square will shrink.  If it is too small, your center square will be too big and you will lose points in the trimming process.

And just to help you, I had my son Jeff help me with this little video :c) Okay,so it's not always centered, it's not scripted, it's just as is..but I think you will be able to tell how I use the Easy Square Jr. to trim these to size easily, and they turn out perfect every time without a lot of waste, and I've got the STRAIGHT GRAIN on the outside edge of my units (just color me a happy quilter!)