This page is adapted from a post I made on Ravelry ‘s Ashford Espinners group, and although I realise that a lot of people just want to spin and create the yarn ‘as it comes’, others may wish to have more control over the outcome. You might for example want a high twist yarn for sock-knitting, or a soft spun yarn for baby clothes. 

When I first got my Ashford E-spinner I just learned how to use it, and wrote a post about that here on my website. 

However, I started to want to design the yarn I was spinning, as I have been able to do on my wheels, on which I can create predictable and replicable yarn for larger projects.  I have written about taking control of your yarn outcomes on a manual wheel here, but it’s different to the Espinner, because you don’t treadle to turn the wheel, so treadles can’t come into the formula. Instead it is revolutions per minute of the flyer as delivered by the motor. This is controlled by a speed dial. 

I have read Mabel Ross’ excellent, if rather dry ‘Handspinner’s Handbook’ and ‘The essentials of Handspinning’ and learned from this, and other sources how to design yarns to my own specification. From working on the wheel I know that although one uses the number of treadles as a guide to the twist it is actually the revolutions of the bobbin per treadle that creates the twist in the yarn.This is then combined with the amount of fibre into which one allows the twist to travel – therefore if the bobbin spins at eight revolutions per treadle and one inch of fibre is allowed through on each treadle there will be roughly eight twists per inch (TPI) in the singles. I say ‘roughly’ because the tension of the brake band will have some effect on TPI.

On the Espinner it is still the same; the revolutions of the bobbin creates the twist., but you need to know the revolutions of the bobbin over a set period of time because you don’t have the treadling as a factor. Instead you need to know the revolutions of the bobbin in a set period of time, in this case one minute. To measure this I bought a little electronic tachometer to find out, and record, the revolutions per minute at progressively increasing settings on the speed dial. Before running the test I studied my speed dial and compared it to a clock face, and in this context it turns from 9 o’clock to about 5 o’clock. I then divided this working area of the dial into evenly spaced sections numbered 1-10. I drew 10 diagrams of the speed dial with the indicator at the approximate corresponding position to where I took the measurements and added in the revs per minute figures at the appropriate dial positions.

Ashford claim the Espinner runs from 0 to 1800 rpm but mine tops out at 1568 rpm. Broadly speaking, at 9 o’clock it runs at 40 rpm, 12 o’clock at 400 rpm and at 3 o’clock its gets to 1140rpm. It reaches its fastest of 1568rpm at 5 o’clock. The increments in between bridge these speeds. This is just an illustration based on my machine, I guess they are all likely to be slightly different. 

Next I timed myself drafting to see how many drafts I made on average per minute , (let’s say 20 for example). I recorded the average length of fibre in each draft which was approximately one inch, but this will vary with the fibre’s staple length and your drafting style, so must be added as appropriate to the calculation.

With the above information I am able to roughly predict my twist. 

Draft = 20 drafts per min

Length = 1 inch per draft. So 20 inches of fibre are drafted per minute.

If I want 8 TPI, I have to multiply 20 (the length) x 8 (the TPI) = 160.

So I need the Espinner bobbin to revolve at 160 revs per minute. This is just past 10 o’clock on my speed dial.

In this example, I can make simple adjustments as follows:

If I want 4TP

I can increase the length of my draft to 2 inches. Which divides the 8 revolutions by 2 = 4.

Or

I can reduce the speed to 80rpm. The calculation for this would be – multiply 20 (the length)  x 4 (the TPI)  = 80.

If I want 6 TPI

I can draft 1.5 inches of fibre. Divide 8 revolutions by 1.5 = 6.

Or 

I can reduce the speed to 120rpm. Multiply 20 (the length) x 6 (the TPI) = 120.

Of course there will always be some flexibility in these figures, just as there is on a wheel, but I found it a good starting point.

Bear in mind that this is for singles only. If you plan to ply the singles together remember that you will have to work backwards from your desired final TPI of the plied yarn to work out what your singles TPI should be for a balanced yarn. This is the same balancing act as on a wheel, it is only how to achieve the desired twist on the Espinner that is different.

Happy, and more controlled spinning!