Thursday, 20 May 2010

I'm back, and armed with yarn length measurements.

I'm back from spending a very instructive and very nice (though also quite exhausting) time in a textile laboratory, measuring the lengths of all the thread samples. For this, I had the use of a thing called "Weife" - a special, very accurate reel with thread guides and a counter, turned with the help of a hand crank. Two full lab days were needed to measure all the thread samples, and I can probably still do the sequence of motions in my sleep: Open small bag, take out thread sample and label, smooth out label, replace empty drinking straw on the "spool-holder" with the sample on its straw, turn crank until counter stands at next full 10 metres, note down the number it stands at (I filled one whole page on a notepad with number after number), search for the spinner questionnaire of that session, double-check that it is the right questionnaire.
Fix end of thread to the reel, start turning the reel (all the while taking care that no snag on the sample spool changes the tension too much or leads to thread breakage). Once the red starter thread turns up, stop cranking on. Temporarily fix the red thread end somewhere to maintain tension and keep everything in place. Read the amount of full metres, then measure the rest down to the last centimetre. Write down amount in metres on both label and spinner questionnaire. Secure the skein with the red starter thread, take down from reel, fold together securely and put back into small plastic ziplock bag together with its label. Place spinner questionnaire on the "done" stack, place finished sample into large ziplock bag. Repeat until all samples of spinner are done, then put stack of questionnaires into large bag too, close bag, put into box, take out next spinner's bag. Start early in the morning and repeat until lab closes.

While this might sound very, very tedious, I actually did still enjoy myself. It would probably have been the most mind-numbing thing ever if that had not been "my" spinning experiment - but as it is, I had a lot of things to discover and marvel about. One of my pastimes was finding out again who had which spinner ID letter - some I did remember at once, and some I needed to read one or two questionnaires. And then, of course, the data! The metres spun! The different thicknesses (though I did not see much of these turning the reel, that blurs up everything). And, most interesting to me, the fact that a spinner complaining about bad, slow spinning in the questionnaire does not at all mean that the thread had to be bad or short - quite on the contrary: Complaints usually meant nothing in regard to thread length. My guess is that a "badly running" spindle will automatically require more concentration and thus a higher output compared to an undemanding one.

Some tidbits of the data: least amount spun was 2,90 metres, maximum length spun was 72,69 metres. Overall, the least amounts were spun on the 15/5 (the spindle from Hell with almost no moment of inertia) and on 52/41 (the thick cylinder whorl with a very high weight compared to its moment of inertia). However, this does not mean that these spindles were not also used productively by some spinners - 60,00 metres and 66,98 metres were also done on those two (by th same spinner, by the way).

Spinner output is influenced by the spindles used, but not in a similar pattern over all spinners, and with the more experienced spinners, there is not as much variation as you might expect given the very, very weird "spindles" used in the experiment. And thread thickness ranges are another very interesting thing: Some spinners seem to have a "thin range" and a "thick range" with a distinct gap between those two.

These are just the very first results, and I hope to get some (or even much) more out of that. There are lots of possibilities now to look at all the variables - which means doing all sorts of different sortings and of course different graphs to see if something can be seen.

It's all very, very very very interesting. I'll be off to play with yummy data some more now...


A Life Long Scholar said...

You recorded the numbers on paper? Doesn't that increase the likelyhood of data-entry errors later, when they are typed into a spreadsheet for data analysis?

Harma said...

The longest length on the spindle from hell must have been from Kerstin. She was "on the jazz" with that spindle the second batch. Proved that that one only works for spinning very thin yarns.

a stitch in time said...

Yes, I recorded on paper. While that might increase the likelyhood of entry errors, it also means that there is a hardcopy version of this crucial data should bad things happen to the data spreadsheet. And since two hard-disk drives died the bad death during my phd time, I have become a tiny bit paranoid about data safety on computers.
And I actually have a lot more trust in my ability to correctly type a short string of numbers than in my ability to _not_ shoot the one and only copy of freshly-entered data from the disk. And there was not enough room on my table to place both the laptop and the paperwork.

Harma, I am totally awed by your memory! Yes, the long batch on SpfHell is Kerstin's, and from the second batch. But she was not the only one to do well on the Spindle from Hell - O managed 56,46 m, and M 53,04 metres (all in the second batch), just to list the three winners of that part of the not-a-competition. Kerstin's very long thin batch is also by far the thinnest thread spun during the experiment, with only about 45 tex (calculated over the whole length of thread and with not very accurate scales, so not totally accurate).

Harma said...

I was spinning next to Kerstin and it was so exiting to see the difference in what she did with the two batches. The first portion she spun over two portions of wool in a very thick yarn, as annoyed with the spindle as we all were. The next morning something clicked and she started spinning very thin and that way the yarn didn't fight the spindle that much, so it stayed turning a lot longer.

Later, back home I thought about this a lot and started experimenting with a spindle someone gave me, with almost the same spinning qualities. Spinning as thin as possible worked on that spindle too. I'll bring that spindle to the next Forum.

a stitch in time said...

Yes, I remember Kerstin's "Flucht nach vorne" (forward escape) and her explanation that she hopes it would spin better with lots of wool on it. And it is interesting that that did not work so well as making very fine thread... and also interesting that you had success on your spindle with very fine stuff (and I'm looking forward to see it).

However, that would mean that a thin thread does not necessarily go together with a light spindle, but rather with a low moment of inertia... makes sense, somehow.

Harma said...

Low moment of inertia goes together with thin thread, but I'm not sure that it's reversable.