following the (eventual) success of finding the measurements for an exact cut method for the 3.5" square-in-a-square block, i've worked out the measurements for the 4.5" block. at first i was a bit perplexed how to do this since the first time around, i simply measured a completed block made with the flip-and-stitch method to discover the completed measurements. but i didn't have a completed 4.5" block to measure. i was going to make one with the other method first, but then i thought i could just draw one and take measurements. and it totally worked! (and despite the wonky, distorted look of the above photo, this block is spot on.)
here are the measurements:
center square - 3 3/8", diagonal orientation
2 corner squares - 3" each, cut in half on the diagonal
below follows a quick demo of cutting for this block.
3/8" rather than 3 1/2" i first cut. the green border on the top two sides of the diamond are 1/8", making this easy.
3/8"measurement looks like the above photo. if you look at the far right side, you can see the little, shorter dash marks on the grid lines that are the 1/8" measurements. it's easiest to see just to the right of the circle with 45 in it (which is marking the angled lines passing thru, not the across measurements).
attach as with the 3.5" block.