You probably don't know anything about making a quilt - but designing quilt blocks requires considerable math. I'm looking for a 'formula' that will help me cut a specific number of fabric strips (cut at a 45 degree angle) that will yield a certain amount of specifically sized squares.
The photo shows a 'mini' version of what I want to be able to do. The 'goal' is to cut 100's of 'half square triangles' (HSTs) with minimal effort. The traditional 'slow' method is to cut a light and dark square 7/8" LARGER then the FINISHED size, stitch on each side of a diagonal line, then cut on the line - to yield TWO half square triangles. Note in the photo that each square (when using bias strips as a 'speed' method) has to be slightly offset to be sure the diagonal falls exactly at the corners.
To determine the needed WIDTH of the bias strips (to end up with the correct size) I use the following formula: To get a 4" FINISHED square, I multiply 4" x 0.71 = 2.84 rounded to 2-7/8". BUT - to make it easier to cut, let's call it 3" plus 1" = 4" wide bias strips. (The 4" size of the finished square, and bias strip width, usually differs, but in this case, it is the same.)
I need to make 128 red squares, and 128 white squares. They need to be a FINISHED (sewn) size of 4" square. BUT - they need to be CUT 4-1/2" square (to allow a 1/4" seam on all sides) - so the 4" bias strips should provide the 4-1/2" cut square.
Here are the basics: The standard width of quilt fabric is 40" to 42". To make handling of the fabric easier, I'll use a panel of fabric cut 20" deep and 40" wide. I will cut 4" diagonal strips from this 20" x 40" panel.
My questions:
1) How many bias strips can I cut from this panel (considering that - measured horizontally - the strips will be slightly larger than their 4" width)?
2) How many bias strips do I need to cut to yield 128 squares?
3) If I want to add a 'fudge factor' - to create slightly larger squares that can be CUT DOWN AND SQUARES UP to the EXACT size needed - is there another formula that could be used, or should I just make the squares a bit larger?
Is there a formula I can use to determine: a) the number of bias strips that can be cut from a panel (determined on the strip width), and b) the number of bias strips needed to yield X amount of squares?
As you can see, this all boils down to geometry - and I am hopeful you can come up with a good, usable formula that will fit any width bias strip and any size finished square.
Millions of quilters will thank you! - including me! Hoping to hear from someone soon! I'll be glad to send a 'mug rug' as a thank you, to the person with the best answer!
The photo shows a 'mini' version of what I want to be able to do. The 'goal' is to cut 100's of 'half square triangles' (HSTs) with minimal effort. The traditional 'slow' method is to cut a light and dark square 7/8" LARGER then the FINISHED size, stitch on each side of a diagonal line, then cut on the line - to yield TWO half square triangles. Note in the photo that each square (when using bias strips as a 'speed' method) has to be slightly offset to be sure the diagonal falls exactly at the corners.
To determine the needed WIDTH of the bias strips (to end up with the correct size) I use the following formula: To get a 4" FINISHED square, I multiply 4" x 0.71 = 2.84 rounded to 2-7/8". BUT - to make it easier to cut, let's call it 3" plus 1" = 4" wide bias strips. (The 4" size of the finished square, and bias strip width, usually differs, but in this case, it is the same.)
I need to make 128 red squares, and 128 white squares. They need to be a FINISHED (sewn) size of 4" square. BUT - they need to be CUT 4-1/2" square (to allow a 1/4" seam on all sides) - so the 4" bias strips should provide the 4-1/2" cut square.
Here are the basics: The standard width of quilt fabric is 40" to 42". To make handling of the fabric easier, I'll use a panel of fabric cut 20" deep and 40" wide. I will cut 4" diagonal strips from this 20" x 40" panel.
My questions:
1) How many bias strips can I cut from this panel (considering that - measured horizontally - the strips will be slightly larger than their 4" width)?
2) How many bias strips do I need to cut to yield 128 squares?
3) If I want to add a 'fudge factor' - to create slightly larger squares that can be CUT DOWN AND SQUARES UP to the EXACT size needed - is there another formula that could be used, or should I just make the squares a bit larger?
Is there a formula I can use to determine: a) the number of bias strips that can be cut from a panel (determined on the strip width), and b) the number of bias strips needed to yield X amount of squares?
As you can see, this all boils down to geometry - and I am hopeful you can come up with a good, usable formula that will fit any width bias strip and any size finished square.
Millions of quilters will thank you! - including me! Hoping to hear from someone soon! I'll be glad to send a 'mug rug' as a thank you, to the person with the best answer!
