My friends. Time has come.
I’m sorry. You know the post isn’t going to be any good. It’s okay to leave now.
The problem du jour is to figure out how many balls of yarn different Tivoli sizes would need… sizes that have never been knit. I have absolutely no idea how other designers figure this out. Absolutely none. But my geometry background is mighty good ;). I remember groaning about having to take Advanced Geometry when I was in college, since I wasn’t studying mathematics, but so far it has proved to be really useful in everyday life!
I decided I would first figure out, what is the surface area (square inches or centimeters) one ball of yarn covers? There are two ways to figure this out – either use a predetermined length of yarn to find out how big or small a square it makes, or knit whatever project with that yarn, and take note of how long one entire ball lasts. The second method is what I chose to use while standardizing the Tivoli.
The hurdle I encountered is that the Tivoli is knit from the top down, and the yoke is not some perfect rectangle made for surface area calculations. So, the Calculus had to come down from the shelf to remind me how to calculate an area of a more complicated geometric shape – a trapezoid. And with the book’s help, I got it:
Okey dokey, 1 ball of yarn lasts about 126 square inches.
Then I did some way more complicated math in Excel to figure out the surface areas of each of the Tivoli sizes:
Doesn’t that look SCARY?
And you want to see the kicker?
The calculations say that the 44″ size needs 7.035 balls of yarn, and the 48″ size needs 8.043 balls of yarn! And I know I’ve been rounding up throughout because I don’t want to be responsible for some poor knitter running out of the proper dye lot – it’s happened to me, and is quite traumatic. But can I in good faith say that the 44″ needs 7 balls, and the 48″ needs 8?
Another nifty thing that came out of my adventures with the Calculus book is that I finally looked up that SOHCAHTOA thing from trigonometry and figured out the length of the Tivoli to shoulder.
I should rename my blog… Grumperina: knitting on another level.0 likes