Tuesday, September 12, 2017

Grist and Using Ashenhurst’s Rule

During a recent spinning gathering, I showed my grist weighing setup and several of us discussed grist and how to relate it to diameter. One lady, an excellent and very experienced spinner, knitter and weaver, mentioned Ashenhurst’s Rule.  Peggy Osterkamp has a nice explanation of it on her blog.  I also read a few scholarly articles about it.

Ashenhurst’s Rule computes a number (A) that is the maximum sett possible from a yarn of certain grist.  It is supposedly a diameter, but no weaver could ever weave something this dense. The best analogy I can think of is absolute zero temperature – when all motion, even atomic motion, stops.  It cannot be achieved, but is it the theoretical maximum cold.

The basic Ashenhurst formula is:

For firm yarns, A = .9*√(YPP)
For woolen yarns, use .86 instead of .9

This is basically the same formula Alden Amos provided in his Big Book of Handspinning, when discussing grist but he doesn't call it Ashenhurst's Rule.  However, later in the book, page 254, he does discuss it.  Since I am not a weaver, I sort of skipped this section and thus failed to connect this rule to spinning.  The original paper by Ashenhurst is listed in his bibliography.

Since this is a theoretical minimum diameter, you still have to adjust this number to get a reasonable diameter for that amount of grist.  In other words, you still have to multiply A by another factor.  This is a sticking point, because few agree on what that factor should be.

Yarn diameter is commonly measured 2 ways: through wrapping or compared against a control card with bars of known thickness.  Both are fairly unreliable measures and very subject to how you measure and perceive things.  While that is true for all measuring devices, measuring WPI is particularly flaky.  Some measure WPI by wrapping the yarn fairly loosely and then shoving the strands together until they just touch.  Alden Amos recommends wrapping the yarn fairly snugly (but not to the point that the yarn flattens) and then shoving the strands together tightly (but not overlapping), known as “pack to refusal”.  The difference between these 2 methods is big.  Measuring against a control card has the problem of laying something round on top of something flat and trying to determine when the 2 diameters match.  Any variation in the angle you are viewing it can change the measurement.  The WPI I get using a card is often one size larger than when using wraps.  Being off one size results in about a 246 yard per pound error - so you need to take some care here.

The real goal is to come up with something that is consistent for you.  In other words, you have to calibrate yourself so that the results are consistent enough for you to achieve the diameter you want.
I got out 10 commercial yarns and 10 of my handspun yarns.  I tried to get a range of diameter sizes of both.  I then measured the grist of each using my mg scale and a centimeter tape.  Since elasticity of yarns varies, I decided to average the lengths gotten when the yarns were stretched and when they were just barely relaxed (straight with no kinking).  I entered all the data on a spreadsheet and did some calculations.

1)  0.cm/0.xmg = m/g * 496.5 = YPP
2)  A was calculated using the 0.9 factor throughout.
3)  I measured the WPI both by wrapping and using the control card.
4) I calculated the ratio of measured WPI to A.
5) I averaged the ratios for the commercial, for the handspun and for all samples.
6) I ran the stats to determine the variability of my samples, which was low enough to be dependable – in other words, I had measured enough yarns to get a good answer. The only yarn I threw out was the acrylic.

The commercial yarns average ratio was 0.55 and the handspun .59.  The higher the ratio, the closer the actual WPI is to A.  This means my handspun is thinner for the same grist as the commercial.  Something I already knew, but now I had a measure of how much thinner.

I am not trying to recreate commercial yarn, because often it is underspun and has its issues, like pilling and other stuff.  But I am trying to better manage both grist and diameter to get a yarn to meet a specific need.  The problem is that I, like most spinners, use twist to get the diameter I want rather using grist and spinning a diameter appropriate to it.  The analogy here might be using a corset to get a small waist, rather than diet and exercise.

Using 0.55 as a reasonable WPI/A ratio, I came up with a guiding table – mind you, this is for me.  Your ratio might be different.

I am now trying to use all this info and see if I can create a yarn with some specific characteristics.  I am aiming for 4 m/g (1986 YPP) and I want the WPI to be around 20 to 21 WPI (my WPI is a bit higher than what the Yarn Council deems as fingering weight, because of how I measure.) This is to be a 2 ply and therefore my singles need to be 1.5 times as fine as the 2 ply, or 30 to 32 WPI.
I took a few grams of the fiber (a dyed, very neppy Targhee) and spun what looked like the right diameter.  I then took a plyback sample.  

 From the get go, I realized I needed a bit more twist to keep this stuff from falling apart.  Then I measured the grist.  First one was too light (5.2m/g), the second one was a bit too heavy, 3.65m/g. On my third try it was just right:  4m/g.  I pulled off some of the singles immediately prior to this sample and wound them stretched onto a card.  This is what the right size should look like while drafting. I measured them to be about 35 WPI.  I also attached the plyback to this card and made some notes.  I will now spin using the card as my guide, but measuring the WPI along the way as well as doing a grist measurement every now and then.  I don’t want to do too many grist samples, as the samples will not become part of the yarn (aka, destructive sample).  

I created a little WPI tool for singles that seems to work well.  Rather than winding to a known width and counting wraps, I created bars that 5 wraps (10 for really thin yarns) should cover at specific WPI.  It is quick and easy to use on the fly and doesn’t require one to pull out a long length of singles.  I have compared the results I get with this to regular wrapping and it is usually right on.
The amount of twist I am putting into the singles is enough to create a pleasing looking plyback that is close to the WPI I want. I will adjust the final diameter using the ply twist, bearing in mind that this yarn will likely bloom a bit.

Tool to determine WPI of singles, based on 5 wraps, except 14WPI, based on 3.
 The backside has even finer WPI.

Will I always try to achieve that .55 ratio?  No.  I can see wanting a higher ratio for something like sock yarn - higher grist and tighter twist to create firm, dense, wear resistant yarns.  I might shoot for a lower ratio for something airy that has a long enough staple to support less twist.  But now I have the measurement tools and knowledge in place to start understanding and learning how to make specific yarns.  (I hope!)

Sunday, August 27, 2017

More on Sampling for Grist

After fooling around with trying to spin a specific number of makes in a 1 gram sample, I found I really couldn’t get the grist I wanted consistently.

So I went back to weighing.  Since I don’t have a McMorran balance, which is expensive and single purpose, my first approach was to make a balance to measure relative weight.  I took a short section of dowel rod into the end of which I stuck a sturdy pin. The dowel rod rests on the top of a vase, placed near the edge of a level table, so that the yarn samples hang freely. Then I bent a piece of stainless steel wire.  The center was bent up and this rests on the needle in the dowel rod. It took a bit of messing to get this wire to hang level, but it is important that it does. See the pictures.

Basic parts for the yarn balance - the dowel rests on a vase, glass or mug set at the edge of a level table.  The wire rests on the needle in the dowel.

To use it, I hang on one side a length of yarn that is at the grist I want (in this case a sport weight measuring about 3.36 meters/gram) and on the other side I hang a sample fresh off the wheel that is self plied. I make sure the samples are at least 18 or more inches long. I cut the commercial sample a bit longer so I can snip off bits of it until I achieve balance.  Then I compare their lengths, holding both equally taut.  Actual length doesn’t matter.  If the commercial is longer than my spun yarn then my grist is too dense, if it is short, my grist is too loose and if they are the same length, then the grists are equal.  The balance is easy to make and costs very little.  It is, however, fiddly to use.  It is also subject to my ability to discern level and other factors.  It's better than nothing and a good way to at least get a sense of what one is trying to achieve.

Comparison yarn on the left and my yarn on the right.  Comparison yarn is gets snipped off until the balance is level - in this case, I'm not quite there yet.  Then the lengths are compared.

One of my favorite tools is my weigh scale that measures to the nearest 0.1 grams.  It’s great for all sorts of things – like measuring out the fiber for each single, determining final skein weight, measuring out larger quantities of dye, etc., etc.  It is, however, not fine enough for grist sampling.  Imagine my delight to find that scales measuring in milligrams (0.001 grams) are available and about half the price of a McMorran balance.  For 20$ I bought a 50 gram scale.  It’s about the size of a simple calculator.  I will be able to more precisely measure smaller quantities of dye and chemicals as well as do quick grist measurements.  

Now came the other issue – how do I measure length?  I collected a bunch of commercial yarns from my stash in various weights and from various manufacturers.  I looked at the ball band to determine what the grist is supposed to be.  For example, a Nature Spun sport weight is supposed to measure 168 meters in a 50 gram skein – or 3.36 m/gram.  I cut a length of it and weighed it.  I divided the weight by the m/g to find out how long the sample should be.  Then I measured.  In most cases the length was somewhere between fully stretched and relaxed.  This actually makes sense, since most yarn measuring devices measure length while the yarn is under some tension.

That led me to another question – how is the WPI measured on these commercial yarns?  I prefer to use a control card rather than wrapping, although I sometimes do that, too.  In all cases again, I had to hold the yarn fairly tightly to get the WPI on the control card that yarn should have with respect to grist and Yarn Council norms.  Not at all like what most people describe for measuring WPI.  I now understand what Alden Amos was driving at when he advocated measuring WPI packed to refusal. 
I ended up making a padded box for the scale, which is big enough to include a centimeter tape, the calibration weight and a calculator.  It’s portable and quick and I am hopefully further along in being able to control the grist of my yarns, besides the diameter.  

My milligrams scale, calculator, centimeter tape and calibration weight.  All fit into the box that I padded with closed cell foam.

I’ll let you know how it goes.

Thursday, August 10, 2017

Getting the Gist of Grist

I have been spinning not quite 4 years.  I have spun miles of yarn and enjoyed every inch of it.  I have knit with it and woven some and am pleased how forgiving the yarn seems to be.  All my hiking socks are knit from handspun.  They fit well, breathe well, I get far fewer blisters and they last.

BUT there is one thing that eludes me.  In all my reading and video watching, the following statements are made: handspun is more dense than commercial and if you want to make a specific yarn you have to pay attention to grist.  These statements are contradictory AND no one really seems to address how to really control grist.

Grist is basically yarn density and is usually described in terms of length per weight, such as Yards Per Pound (YPP) or Meters per Kilogram.  Since I have knit decades more than I have spun, I prefer to express grist as meters per gram, because I can then relate that more easily to skeins, which usually come in 25, 50 or 100 gram weights.  (M/Gr = YPP/496.5)

So after I have spun, plied and washed a skein, I measure the length in meters and divide by its weight in grams.  Unfortunately, although it looks and measures perhaps as a fingering weight (16-18 wpi), the grist more often tells me that it’s more a sport or even a DK weight.  Fingering weight usually is somewhere between 3.5-4.5 m/gr, sport weight is more like 3-3.5 m/gr, DK ranges from 2.5 – 3 m/gr and worsted weight is 1.5 to 2.5 m/ gram.  These are approximate and don’t totally jive with the Yarn Council numbers, but they work for me.  The problem comes when knitting with yarn.  The gauge and resulting fabric behaves more according to grist than according to yarn diameter.  Makes sense – you can only compact fiber down so far.  So basically the novice spinner substitutes twist to achieve diameter rather than concentrating on grist.  I have come to the conclusion, if you spin to grist, the diameter takes care of itself.

So how do you achieve desired grist?  The McMorran balance often is mentioned, but that is only a spot sample.  I have done something similar – created a little balance from wire, put a length of a sample yarn of desired grist on one side and the same length of my project yarn on the other.  If they balance, their grists are the same.  But that’s only a spot sample.  Not really useful over the course of a project.

So here what I have been doing.  I haven’t done this enough to know if this consistently works, but it should. First I decide what grist the final yarn is to have.  For example, I want a sport weight of 3m/gr.  It’s to be a 2 ply, so 3*2 means the singles grist should be 6m/gr.  Since I prefer a backward draw – whether short for worsted draft or long for woolen – I can measure a comfortable make – like 45cm (about 18 inches).  If 1 gram of fiber is to measure 6 meters, then 600cm/45 cm per make = 13 to 14 makes. I am aware that final length won’t be what the stretched length while spinning is – I figure at least 10% length reduction.  So I shoot for a slightly higher number of makes to take that into account – 15 makes would probably be better.  If you use a forward draw for worsted, you'd have to measure about how much you draw out each time and go from there.

  I play with this until I understand what this grist looks and feels like.  I repeat this every so often to make sure I am staying more or less at this grist.  I then worry about twist and do ply backs to see if I like what I see.  I adjust pedaling rate and/or whorls if I don’t.  I do not worry about diameter – I figure the grist will take care of that.  

The question is, if this is a reasonable approach or not – feedback most welcome!

Tuesday, June 20, 2017

Row Counter

It has been a very long time that I wrote anything here.  Not that I haven't had anything to write about - I have been doing so many different things - but I am lazy.  This entry is motivated from some questions some folks had about the row counter I use when knitting.

Liz Upitis in her book about Latvian mittens talks about using a loop of yarn that is tied into subloops.  Each time you knit a round, you slip your needle into the next loop down.  Say you need to cross a cable every 8 rows.  You create an 8 loop counter.  After going through all 8 loops, you do the cable cross and start over.  Recently I saw a blog post that shows doing the same thing with locking stitch markers.

As a forester I often had to lay out boundary and cruising plot lines using a handcompass and pacing.  To keep track of my paces I used either a clicker (much like the clickers knitters use) or pacing beads. Pacing beads consist of two cords linked together on a loop or carabiner.  One cord carries 9 or 10 beads and the other usually about 5 beads.  You slide one of ten beads to the end of the cord each time you have paced a certain distance (every 20 meters, every 50 meters - whatever).  After counting ten of these, you slide one of the five bead set to the end of these cords.  Then you start over with the 10 count.  That way you can count at least 50 - technically 60 - such distances.

The Upitis method got me to thinking that I could make a mini pacing bead set and accomplish the same thing. Additionally you could use them to count 2 different things - like decreasing every 3 round while cabling every 8 rounds, etc.

I use a split ring that works with the needle size.  Cotton crochet thread doubled works well with the small beads - they slide only when you want them to.  Split rings also work well as stitch makers.  They are thinner than standard stitch markers and don't mess with your gauge as I have found the fat plastic ones do.

Anyway, try it and let me know if you like it!

Sunday, January 3, 2016

Darning by Knitting

I changed the name of my blog, because I think it better reflects where I have been going these past few years: from almost exclusively quilting to all sorts of fiber fun.  I still quilt, but knitting, spinning and weaving take bigger chunks of my creative time.  I still climb, but much more modestly, and so I felt Quilting Climber was inaccurate and maybe pretentious.  I hoped to blog more because of the name change, but I obviously haven’t been.  However, this topic came up in a forum on Ravelry and rather than clutter up a thread, I thought I’d post this technique here.

This isn’t necessarily new but certainly doesn’t show up in any of my resources.  I first started doing this, because a young friend of mine ripped the heck out of a sweater.  He guides hunting trips in Montana, when he isn’t a backcountry wilderness ranger.  He got jumped by a grizzly while gutting an elk and ripped one of his sweater sleeves in several places during his hasty exit through the brush.  It’s a his favorite sweater and after some thinking, I decided it would be best to flat out knit the patches and graft them into the knitting as I went.  The results were excellent and I have used it on some other items, including socks with good results.  It’s fast, easy and I think better than anything else I have tried.

Before I explain this technique, I want to share my thoughts on darning socks.  Socks tend to get holes where you also tend to get blisters. The rubbing action that wears out socks also is hard on your skin.  A patch will only aggravate that area, possibly causing worse blisters.  And there’s nothing so miserable than having to work all day (I was a field forester) or hike out of the backcountry with blistered feet.  I relegate mended socks to knocking around town or to in the house status where I am not likely to walk enough to get blisters.  In the field, I wear good, perfect socks to protect my feet.

Here are the steps to a knitted patch:
You will need:

  • At least 2 dp’s – preferably slightly smaller than what was used to create the item.  This makes picking up the stitches easier and the patch denser and durable.
  • Yarn identical to the item, or of a thickness equal or possibly thinner than the item.  You don’t want the patch to be too bulky.  I try to save a small ball of all items I have knitted for this purpose.  Not that I can find it when needed…  You might add a strand of wooley nylon or the like if this is a high wear area.
  • A tapestry needle for grafting and weaving in the ends.
 The procedure:
  • About 2 rows below the lowest extent of the hole, pick up the right hand leg of each knit stitch, starting 2 columns left and ending 2 columns right of the hole’s width.
Picking up initial stitches.
  •  Knit that needle and turn the work, and knit back, using the stitches that match the item.
  • Pick up a stitch in the column above with your right needle.  Knit the first stitch from the left needle and pass the picked up stitch over it.  Finish that row.  And turn your work.
  • Repeat the step above each way until the knitted patch extends two rows above the highest point of the hole.  End with a RIGHT SIDE row.
  • Cut the yarn, leaving a tail 3 times the work width plus a bit.
  • With the free DP, pick up the stitches 2 rows above the hole and of equal number as in the patch.
  • Holding this needle in front and the patch behind, graft the patch to the picked up stitches.
Getting ready to graft.  See that the edges barely show the passed over picked up stitch.
  •  Bring the starting and ending yarn ends to the wrong side and weave in.
Finished patch.  The orange is a patch done by Swiss darning and it looks awful.

The cool part, besides looking nice, is that you can maintain the stitch pattern or even the stranding pattern in the patch as should have been in the item there, creating a very seamless repair.