Archive for June, 2011

Oh the math!

Saturday, June 18th, 2011

There are many knitting programs that will perform the necessary calculations, as well as a variety of knit calculators. The diophantine formula is the basis for what is know to some knitters as the “magic formula”. In the early 1980s Alles Hutchinson authored a small book on the subject. There is a bit of personal leeway in the results, and the formula may be used in calculating even complex shapes with the proviso that one has the patience to break such shapes into series of simpler ones.

There are many online resources for information and calculators to sort out the math. Kathleen Kinder has written on the subject and has kindly made available some of her writings on the subject online as a word document . The eHow on use of a home calculator . PC formula calculator download . The UK knit and crochet guild shares their version on the topic . For online math including a triangle calculator .

Using the gauge to match the previous post of 4S and 6R per inch the calculation for the pie divided into five triangles  breaks down into the web calculator result pictured below:

The longhand method for same calculation which follows and also translates to: bring into hold 2 stitches for 4 times, 1 stitch for 80 times. Stitches in shaping are proofed as above: 88 stitches shaped over 84 rows.

Knitting math and pies

Saturday, June 18th, 2011

Math is non always fun, and is downright dreaded by some. One instance in knitting wherein basic calculations are required is in obtaining stitch and row gauges. I have known one hand knitter who would purchase yarn (not necessarily the one used in pattern), knit happily away, and try the finished product on everyone she knew until she found an accommodating body shape and size. If the large number of family and friends did not oblige, sweaters were stored until such a correct body appeared. Predictable results require careful measurements and some basic formula calculations.

Using home knitting machines to produce circular forms one resorts to breaking down the round object into pie wedges, which in turn are knit as triangles with straight line outer edges. The outer final circumference curve is controlled in a number of ways, one is by creating a far greater number of pie slices. For this exercise I will work with 5 segments. 

There are some math constants. One example: to find the circumference of a circle its diameter is multiplied by pi = 3.14. If the diameter of our knit is 44 inches, its circumference will measure 44 X 3.14 = 138.16 inches. Using the rule of 5 or less than 5, this measurement is rounded to 138 inches.

The radius becomes the width of the pie wedge. In this instance, it would measure 22 inches. Let us assume our gauge is 4 stitches and 6 rows per inch. The radius is converted to stitches: 22 X 4 = 88 sts. The circumference becomes rows:  138 X 6 = 828 rs.  If subdivided into 5 slices, each slice would be composed of 166 rows.

To knit the pie slice, short row are used ; since they happen every 2 rows, our row number for outer edge is divided by 2, yielding the total of now 83, which in this exercise I will round off to the even # 84.

Mannequins with personality

Friday, June 17th, 2011

Mannequin collections.

Life may keep me from knitting, but not from surfing!

Friday, June 17th, 2011

The UK blog of a knit enthusiast from that part of the planet.

More UK eye candy

Tuesday, June 14th, 2011

A site that states its goal is “discovering and supporting pioneers in contemporary fashion”. A wealth of links, interviews, competitions, news, editorials and online shop are included.

OY!

Sunday, June 12th, 2011

Home repairs, new computer, family distractions: to quote John Lennon, ““Life is what happens to you while youre busy making other plans”. I hope to return to my ramblings and maybe even some actual knitting over the next week. A quick note of thanks for the many comments left by visitors in the interim.

I have often had mixed feelings about Vogue Knitting. They have a new web presence . Please note that, as explained by the publisher, you may encounter some issues when visiting. Choppiness may be due to gap between download and play speeds, may resolve itself or page may have to be refreshed. If the latest version of Adobe Flash player is not available or capable of being installed in your computer, the screen may be blank or absent. That said, this is a different way to view their knit offerings, entice new magazine subscriptions, or simply to find some inspiration and ideas.

For those with Mac OS X 10.5 or later, Intel only, Google Chrome is free and installs in minutes. It has a translation component that can help when you come across pages written in other than your spoken languages.

Approaching “circular knits” on the machine: a series

Friday, June 3rd, 2011

Circular sweaters and vests have been in the pattern marketplace for a while, and there are a very few online resources for purchasing patterns for machine knitting. My first attempt at one such pattern was a hand knit for my grand- daughter. It began on long circulars and was worked from the outer diameter, with stitches decreased at intervals, eventually bound off at center. Most adult sweaters and vests both in HK and crochet are worked from the center out. A common diagram for such sweaters regardless of approach is seen below, a vest could result by simply omitting the sleeves.

Diagram A

Placement and shapes of sleeves is crucial to fit. A straight sleeve top as seen in dropped shoulder sweaters can result on the sleeve opening occurring on the arm inches below the shoulder, making the top of the circle that forms the collar flop around, and the sweater is hard to keep on (the result in my hand knit). Better shoulder fit and having a cap at the top of the sleeve, whether traditional or raglan, and adjusting back garment width can achieve stability. In large sizes created by simply making the circle larger, the fit becomes very different in the front, and there are other, better ways to achieve a similar look. Calculations involved in planning these garments share common methods with “doilies”, shawls, ruffles, and more.

In hand knit/crochet another approach is to knit a square/rectangle variant, which can begin and end in open stitches. This piece is folded in half, circulars are used to pick up all the open stitches which now become the inner diameter of a circle, and increases are made regularly, evenly across the rows at intervals to achieve the desired outer diameter. The opening created by the folded fabric becomes the armhole, which may have to be partially stitched closed upon completion of the piece depending on size requirements.

Diagram B: red line represents fold

On the home knitting machines evenly spaced increases and decreases are possible but not practical, requiring removal of knit whether on garter bar or ravel cord, with rehanging of all the stitches after adjusting the number of needles in use. Patterning can continue if this is done on plain knit rows, and design shifts are taken into consideration. Though circular knits can be achieved using a ribber, there are distinct differences in tension between the two beds in Japanese machines, not so in Passap knitting. Here again, increasing/decreasing evenly across rows impractical if not impossible. Increases along outer edges of the knit are easy, but the result in a series of triangles meeting and pointing down from garment on that edge, a common sight in the marketplace at the moment, but not so good if a circle is the desired shape. One approach on the machine can be seen in the diagram below. The central shape is shared with the above diagram, but the circle is broken up so the garment becomes a flat construct. “Extra” smaller rectangles on side represent a possible longer cap sleeve. Here the whole piece would be folded in half and seamed. If center shape has straight sides adjustments can be made in seaming for desired armhole measurement. The remaining probem: how to get that outer “diameter” created by the bottom and top of the piece to approach width needed without increases and decreases across rows. With this approach the seams that bring the top and bottom sections together will move toward the front of the garment, so joining method and its visibility is a consideration.

Diagram C