## Monday, August 19, 2013

### Math for Spinners, or, Maxxing out the Traddy

Spinning fine takes time. No joking. How much time?

I've run through some numbers, and for you math geeks here they are:

My goal is sock yarn: 400m 4-ply for a 100g hank. This means 1600m of singles (at least!) out of that 100g roving, which works out to a grist of about 8000 ypp (16 m/g in metric).

I have the following:
• maximum flyer whorl ratio 10:1 (I have a 1980's Traddy)
• treadle speed 2/sec (this is about the maximum that is comfortable for me to maintain for any length of time), which, on the above ratio, means 20 rotations of the flyer per second. In other words, it's buzzing at 1200 RPM. Note that this is treadling very fast. A more comfortable rate is 90 treades/minute (1.5 treadles/sec). Slow treadling is 1 per second. I'm such a geek that I've actually used a metronome to establish treadling rates!
• Drafting speed 2" or 5cm per second - this means inserted twist at ~10 twists per inch ("TPI") (actually probably a little less), which seems to be good for the type of yarn I'm getting so far (may have to go a little higher as a I get thinner). I find the drafting actually quite slow.
...so, to spin 1600m of singles will take me (at 5 cm/sec) about 9 hours. And, of course, more time still because it doesn't include the plying. Uh-oh.

So, you can appreciate why I am looking into getting additional equipment to boost the speed!

How about a lace flyer? This is a thin (more aerodynamic) flyer with a tiny whorl on it, that has a ratio of up to 40:1, according to the Ashford website. If I maintain the same treadling speed, this will cause the flyer to buzz around at 4800 RPM, so to maintain the same TPI I will have to draft 4x as fast (20 cm/second - not sure I can handle that worsted!), which will reduce my spinning time to a much more palatable 2-3 hours.