Who needs math? Funny you should ask…

Remember that guy in the tenth grade who would torment your math teacher by asking, “When are we ever going to use this crap?” Or perhaps you grew up in a nicer neighborhood where that guy said, “When are we ever going to use this stuff?”

I’m here to tell you, ladies and gentlemen, that I am USING THAT STUFF. I have just USED IT. I have braided that math into a nice little charm bracelet for my wrist.

To whit, check it. What you are about to see has just made my brain hurt so bad that I think I need a lie-down. Which is fitting, since it’s midnight.

What the WHAT?, I can hear you thinking. What on earth is that? That, friends, is the set of calculations — that I programmed into Excel — required to figure out a set-in sleeve on a sweater. There are simpler sleeves that have squarer shapes (read: easier math), but this curvier sleeve fits the human body better.

To determine the shape of that sleeve, you have to use:

  • the Pythagorean theorem
  • parentheses to signal to Excel which operations get done first
  • the vague memory that any number to the 1/2 power is the same thing as the square root of that number (I was super-dee-duper impressed with myself for remembering that one)
  • and other whatnot

The numbers all look consistent with each other, so now I just have to check that they will fit an actual human body. That’s where the physics comes in — that is, the knitting.

If you’re thinking I’m pretty awesome right now — and I feel certain that you are — then let me give credit where credit is due. I’ve been learning how to calculate sleeve caps from a wonderful online class with Knitgrrl Studios. And I have learned a tremendous amount about how to make Excel do some of the work for you from the stupendously generous Marnie Maclean. Really, that woman deserves a medal.

Geometry is not my friend

I think it’s time to frog my brain. For this toddler western shirt that I’m designing, I’m trying to do top-down, set-in sleeves done with short rows. Why? I don’t know. It must be my inner masochist talking.

I found a good tutorial online (which of course I cannot now find again), and merrily got to work.

Attempt #1: Blithely smoked my way down to the cuff. Found that in the cotton blend I’m using (Brown Sheep Cotton Fleece), the short row wraps + decreases look really gappy and strange. Decided to ignore this basic flaw. Got all the nice piping and button placket detailing done. Realized that I had misread the directions about how many decreases to do at the top of the sleeve. Blast.

Attempt #2: Did the correct number of decreases. Still had the gapping problem. Also noticing that the underarm looks like it has too many stitches. Double blast.

Attempt #3: Cast on fewer stitches under the arm (only 2 sts for every 3). It’s looking better, but I haven’t determined a solution for the gap problem. I want this pattern to be accessible to an intermediate knitter, so I need a reasonably simple solution.

Part of my problem is just seeing the geometry of the situation. I’m used to doing set-in sleeves as separate pieces and from the bottom up, so I know what needs to happen to make it the right shape. But I can’t seem to wrap my head around the spatial flip of doing it top-down and in the round and attached to the body all at the same time.

Perhaps it’s time to break down and buy the Maggie Righetti book? (OMG, did you know that you can preview the book on Google Books? Google Books rocks my world.) Montse Stanley, wonderful as she is, does not say boo about top-down, set-in sleeves.

Your intrepid fledgling designer soldiers on. I will leave you with this one riposte: I am not the proverbial knitter who is afraid of all math. I am chums with algebra. I have calculus over for tea. But geometry? It is my sworn enemy.