Wednesday, September 21, 2011

DRS Revisited

I have been plying yarn for my Shetland gansey.  Some of the singles were spun last winter before I built the Hot Rod and some after. 

Running the singles through my fingers, I am impressed by the consistent fineness of the singles spun using the Ashford high speed whorl and bobbins with whorls that provide the proper DRS (differential rotation speed) for the grist of yarn being spun.  While the Hot Rod certainly allows me to spin faster, singles spun on it tend to drift in thickness.  For example, singles that I intend to be ~9,000 ypp end up with portions being closer to 7,000 ypp or 11,000 ypp.  I think this is because with the small whorls, a small change in anything changes the DRS.  While the standard Ashford high speed whorl is twice as large, so the same change in that system makes only half as much change in its DRS. 

Anyway, I am going to move toward larger whorls so that I have better control of my  DRS.  I have not decided if I am going to do that by putting an accelerator wheel on the Traddy or if I will buy a 30 inch wheel.  

Most of last week, I had the Ashford Lace Flier (ST) on the wheel.  First and foremost, I do not think that there is any question that a good bumpless driveband (per Amos) delivers more power than the Ashford Turbo driveband (clear stretchy plastic).  2)  Fluorocarbon leader material (fishing line) makes very good brake band material for spinning very fine yarns. 

As long as we are talking about spinning fine, see the Bothwell Spining results at   The winners are spinning singles up in the range of 100,000 ypp or 176 hanks/ lb. The winner, Jan Zandbelt, currently uses a Louet Julia, but in 2007, he used a Majacraft Suzie with 1 gram of brake tension and custom made ultra-light weight spinning bobbins.  Of course, that contradicts my thoughts about DD being better for spinning fine.  Or, does it?

I do not spin that fine.  I do not try to spin that fine.  I do not need singles finer than about 27,000 ypp.  I aim to spin my finest singles at ~90% of  their spinning count.  Thus, Polwarth has a spinning count of ~ 62, so I would aim to spin it at ~ 31,000 ypp.  Zandbelt spins it at 88,400 ypp.

Does that invalidate everything that I say?  I want yarns that knit up into fabrics that I like, and I want to produce those yarns with a minimum of effort. Zandbelt wants thin yarn for contests. He says that "Patience"  is important.  We have different goals.   

However, I am arrogant enough to think that if I wanted to spin Polwarth  into a yarn that was too fragile for any practical use, I could.   I would approach the problem by making up a DD spinning bobbin with a DRS of 1.01 and a bobbin core diameter of 0.625".  I think that for that low a DRS, I would use the regular Ashford DD flier whorl, which gives me a bobbin whorl diameter of 1.73". We are talking a bobbin speed of 1,200 RPM.  My bobbin has not gone that slow in ages.  It would take all weekend to spin 10 grams. "Patience" is right. 


Debbie said...

I have been reading your blog for some time and referring others to it. I have also purchased a knitting sheathe and needles from you but have not tested them out yet. You mention knitting a garment to a particular ease as that will allow a gansey to vent and not cause the wearer to overheat - but I don't recall you mentioning what would constitute adequate ease. I have looked at historical gansey pictures and they were quite close-fitting. There is a lot of spinning and knitting time dedicated to one of these garments. I hate having to unravel when they don't fit right. Any thoughts?? My husband is a house framer and works outside all winter. He wears handknit wool sweaters and accessories and tends to be the only one who is warm on his crew when it is really cold. I admit that I prefer that he only wear his handspun handknit sweaters when he wears his coveralls over them to save them from the chalk dust/nails/other accidents. But I know that he could be more comfortable if his woolens performed better.

Aaron said...

That is a really good question.

It depends on the density and thickness of the fabric, how cold it is, how windy it is (wind does go through knit fabrics), how hard he is working, & the size and shape of the neck.

I discovered venting in s sweater that is quite close fitting by modern standards. On the other hand, it is so tightly knit that I can lay it on the floor, pour a bottle of water on it and the floor will stay dry.

It takes a really tight fabric to vent properly. Unless you are using the knitting sheath, you are not likely to knit that tight.

If there is enough ease that he can get his hand under the sweater to scratch, there is enough ease to vent. If it is skin tight, and his ears bleed when he pulls it over his head, then it is not going to vent and he will sweat in the pub.

DebbieD said...

Aahh! But the knitting sheathe is the plan. And some combed handspun cotswald, I think. I have a picture in my head of the sweater I want to make - I have been working on getting the fleece ready to comb. I was hoping to get some of the sweater schematics figured out in my head while I comb. Then maybe the knitting won't be as arduous (as in knit, rip out, knit some more, rip out some more - which are my perfectionist tendencies sticking out more than anything). I am hoping that if I get more donw on paper first, there will be less unravelling. Thanx for the info.

Aaron said...

I love the book, Knitting in the Old Way by P. A. Gibson-Roberts & D. Robson.

It helped me make sense, and learn to knit it once.

I also believe in J. Fee's/B. Brown-Reinsel concept of knitting a little one. Knitting a teddy bear sized sweater allows you to practice the stitches and work out all the details, before you go for the big one where a slip-up would land you in a big nasty frog pond.