A Simple Job Made Harder & My Head Hurts

This happens--a simple job becomes hard, that is, making large setting triangles for this churn dash quilt--when you don't have the tools to make it easy.  

The blocks finish at 8 3/4".  By the generally accepted calculations for side triangles (size of block x 1.414 + 1.25) I need to cut 14" squares, then cut twice diagonally.  That gives close to an exact fit.  If that's what I wanted, it would be fine, but I need to add (because the quilt would finish at 58 3/4" wide, I really do need to add) width--several inches of width.   Increasing the size of the square by 2" (from 14" to 16") adds 1" per side.  An 18" square would allow the triangle to extend 2" beyond the blocks at the edges to give a final measurement of 62".  That's still narrow for a quilt.

The challenge comes because my largest cutting mat is 17 3/4" x 23 3/4" with marked of 17" x 23".  Too small.  My biggest square ruler is 12", also too small.  My biggest long ruler is 6" x 24", which should be big enough.  . 

Trying to figure how best to do this makes my head hurt.

I have both Easy Angle and Companion Angle rulers but the Companion Angle's biggest triangle would be the equivalent of an 11" block cut diagonally twice.  It falls short of the minimum size to fit the blocks by 3".  (Do they even make larger Companion Angle rulers?)

Common sense tells me there must be a way to do this without using one of the angle rulers, but not without the long ruler to get a straight cut.

My first idea was to cut a square of paper as large as I need it and use it as a template.  I had a 14" x 20" piece, so used that to make a 14" square.  When I placed it by the blocks I knew it was too small.  I tried it with a larger paper and cut an 18" square.  Better.  But imagine trying to hold paper in place to use it as a template to cut an 18" square of fabric?

My next thought was based on the idea of the Companion Angle ruler.  Cut strips of fabric the height needed for a side triangle, then use one triangle from the paper square (having cut it diagonally twice) as a template.  But there I am again with a paper template on fabric.  Tape it down?  Cut the first diagonal on the fabric using a ruler, then use the template and ruler to cut the other side of the triangle?

The last idea I had was to cut a square as large as I need it, cut once diagonally, then rearrange the triangles so I can sew two straight edges together in the configuration for a setting triangle.  But do I really want that seam down the center of a setting triangle?  I don't think so.

None of these ideas seem simple or easy.  How DID those early quilters manage to cut large pieces of fabric without the aid of our modern rulers and templates?!  How did they make squares that were square and triangles that were accurate?  How did they cut long strips that were the same width along the whole length?  There's some part of me feels like I've missed out on some essential quilting information because I must use tools to make everything easy and simple.  Don't get me wrong.  I'm thrilled with easy and simple, but there are times when knowing the harder way might actually make the job easier.

This is a challenge ONLY because I want larger-than-usual setting triangles.

Maybe none of these ideas will work to cut over-large setting triangles.  Maybe, if got them cut, sewing them to the quilt won't work!  Maybe I won't like the look of those over-large setting triangles. 

I'll work on the possibilities on Tuesday and hope to actually cut the triangles on Wednesday.

Have you ever cut over-large setting triangles?  How did you do it?  Do you have ideas for how to make cutting these triangles simple?

Thanks for visiting and reading.

--Nancy.