Measurements for new way to make HST?
 

I know there's a new way to make HST but I don't know how you figure out the measurements. I know you cut out two squares of equal size and put RST and then sew 1/4" around the outside of the block and cut it into 4 triangles and it give you 4 HST. But if you want the end result to be 2 1/2", how big of pieces of fabric should I cut? Is there a way to figure any size of HST out?

I only use the two HST method. The one you're using gets me too confused. Two squares RST as you said. Draw diagonal line, corner to corner, on the back of the lighter one so you can see it. Sew 1/4" from the line first one way then on the other side of the line. These are easy to chain piece. Then cut in two on the line and you have two HST. My measurements are 1/2" bigger squares to start. So.....start with 6" squares, RST, and when you cut apart you should have two 5 1/2" HST finished.

I also only do 2 HST's at a time. Doing the method with 4 as you describe leaves bias edges on all outside edges. These can be a bear to sew and have a tendency to get very wonky with handling.

I agree with Christine

I just did 2 HST's for a wall hanging boarder and they were super easy. I think Fons and Porter makes a ruler for this but the description above works just as good if not better.

I have the same question. The 5 inch charm comes to about 3 inches which can be squared off to 2.5. Missouri Star Quilt originated this ask the question on their blog. I am going to try different size squares to find out.

this is one of the easiest methods to figure out.... remember that on your double layer square, you will be drawing a big 'X' so you can cut accurately when done (you don't really need to do this... it's just nice to see one or two done, cut, pressed seams set, open, and press open to measure and check our method... once you do one or two.... just cut your big squares and go.... you are sewing around the edge with your 1/4" foot so there is no need to mark the 'X'..... okay.... but draw one right now... a square with the 'X' in it..... see the center where the cross is? that is one of the CORNERS of your eventual HST.... see it? from corner (at seam) to center of square is one SIDE of your HST.... so your cross must be twice the length of your needed HST.... 2.5" HST? you much have 5" (ON THE DIAGONAL!!!, just measure the diagonal line on one of your big rulers... then follow to the edge to see the size of the squrare) (2 'X') and then the seam for the 5" (5.5") AND if you're like me.... i trim all HSTs before sewing them to anything so i need another seam for trimming... so 6"...
now I sew the 1/4"... down to 5.5"...
cut apart from corner to corner, and i still have a bit to trim so they will be perfect size and flat... press before trimming, this is a job for the TV at night, good light, bread board to work on, little board to cut on and rotate on, rotary cutter and good (small, in this case) square-up ruler.... it takes a bit of time but you will love the result if you have never done this before...

this is NOT new...BIllie Lauder started this many years ago!

Sorry can't answer the question. I just wanted to say that I don't like that method because of all the bias edges. I don't like to be that careful with my HSTs and rather use the standard square to make 2 and then cut them down.

I have cut my squares at 4 1/4" square. This allows you to trim a little to get a 2 1/2" HST.