Spindle Physics, or, why some spindles are fast, some spin forever, and most are somewhere in between...
I often talk to people about "spindle physics" in my booth, because their favorite question is, "which spindle spins the best?" And of course, the answer is, "that depends..."
There are physical attributes of spindles that assist in spinning certain types of fiber and certain types of yarn.
Spindle weight in drop spindles assists in spinning to a particular range of yarn thickness (wraps per inch, in technical terms). For finer singles, look for lighter spindles -- typically 1/2 ounce or less (15 grams) for laceweight and finer singles; about 1 ounce (28 grams) for fingering; and up to 2 ounces for worsted weight yarns and thicker. But note -- as you fill the spindle, you change how much it weighs! Fine spinning tends to get interrupted once the spindle has about 1/3 of its original weight again in fiber on it. Chunkier spinning is usually aided by the additional weight, so it can take more. I've seen spindles with upwards of 4-6 ounces of fiber on them! Sheesh! (Yes, that's alot -- me, I'm lucky to get 1 ounce on, as with my wrists, that's all I can take in extra weight.
But notice I said drop spindles -- top whorls and bottom whorls. Support spindles are mostly driven by the other attribute of spindle physics, the impact of the mass distribution on the rotational behavior of the spindle.
No, Dorothy, I don't have a degree in physics. Nor do I want one. I took that class twice in college, and have no desire to repeat it. I've no idea if it's centrifugal or centripital force, just that if I flick the spindle, it will keep going for a while.
What do I mean by mass distribution, or the shape of the spindle? (1) Weight out at the rim of the whorl == longer spin. (2) Weight in at the shaft == faster spin. Yes, you can have both of these. A wider diameter whorl with rim weighting should spin longer than a smaller diameter whorl with the same whorl shape. And a whorl that is tight in to the shaft like the Natalie will be a fast spinner, not a long spinner. Good for silk, which needs alot of twist.
Case studies on spindle shape:
The Forrester Granny Spindle (aka drilled spindles) have actual holes drilled in them half way between the shaft and the outer edge of the whorl, around the whorl. So, they've actually removed mass right where it doesn't help. This maximizes the impact of the weight that exists -- the outer rim of the whorl, and the shaft itself.
Bosworth Spindles have a very deep channel cut in a ring between the shaft and the outer edge of the whorl. They've left wood near the shaft too. This design has been the most successful one I've run across to combine the physics of both fast and long into a single spindle. Some people find it too successful -- they say it spins too quickly for them. But you can counteract that by putting a little less oomph in your twirl.
Bosworths are interesting too in that they come in 4 different profiles -- Featherweight is not as deep of a whorl as the Mini, though they have the same diameter; Midi is a mid-sized spindle, and the Maxi or Large is their largest diameter whorl. This lets you compare length of spin by weight -- you could find a dense wood midi and a light wood large at close to the same weights; you would expect the large to spin longer than the midi -- and it probably would. I sense a future experiment coming on!
Tabachek spindles use a "flywheel" shape -- carved out mid-whorl, bead of whorl-wood at the rim and another bead near the shaft. Generally not as high a whorl shape as the Bosworth, these also have a nice combination of fast and long spin to them. I find them a very successful spindle also, in that Mr. Tabachek will occasionally use an exotic wood on the shaft -- Purpleheart shafts give you even more shaft weight, for a nice, zippy spindle!
Tabacheks also provide a variety of sizes; the mini Tabacheks in exotic woods can have enough heft to them to be very fast spindles -- terrific for high twist, fine spinning. And his latest spindle, the plying spindle, has the double advantage of a super-wide whorl for long spinning and a super-wide whorl for holding a really big cop of yarn!
Kundert spindles have a very nice umbrella shaping, again like the Tabacheks with a bead of whorl-wood at the rim. The shape is such that you must turn the spindle over to see the carved out underside -- from the top, it looks like a smooth umbrella surface. Kunderts often feel like they are getting a "lift" from this shaping. They have a single whorl dimension, about 3 inches, one of the most often recommended sizes for beginning spindlers. This is a really nice whorl size for long spins, and, as with the Tabachek Plying spindles, for holding a large cop of yarn.
The Natalie spindle is very different from all of the above spindles. However, it has predecessors -- the Victorian Silk Spindles written up in Bette Hochberg's book Handspindles, and Hatchtown Farm's Lady Ann spindle. There are And it also has "cousins" -- spindles that apply the same physics with their own shaping, such as the Will Taylor Victorian spindle, the Grafton Fiber FiberShip, and the Doug Peake Wendy. But enough comparisons!
The Natalie is all about keeping mass near the shaft for a fast spin. Also it uses dense woods such as Ebony and Purpleheart, to ensure the spindle has enough mass to keep spinning. The lighter a Natalie is, the shorter its spin time. At a bit over an ounce to 1.4 ounces, it spins reasonably long -- sitting, I can often "spin it to the ground", though standing it usually finishes spinning before I reach the floor. Natalies spin very fast, though, while they are spinning. This helps for spinning fine singles, as it gets twist into the yarn very quickly to ensure it will hold together. The finer your singles, the more twist they need to be held together. The weight of the Natalie, however, means it is best suited to long-staple fibers such as silk, or to any fibers that have plenty of silk blended in. I've spun lovely cashmere/silk blends on Natalies with great enjoyment, down to "frog hair" dimensions; but they are not cotton spindles, as the short staple length combined with the weight of the Natalie will cause a fair amount of droping for all but the most persistent spindlers.
In almost all the Ahka spindles I have seen, they maximize mass close to the shaft. Since this is a support spindle, this will ensure a fast spin for the duration of its spin. As the description on Ahka spindling teaches, generally the Ahka technique doesn't lead to a long spin, so the fast-spin design of the spindle maximizes its spin-formance.
Generalizing Navajo Spindles, these seem to typically have a flat whorl shape, not maximizing rim or shaft weight. To be honest, I haven't studied or considered alternate Navajo spindle whorl configurations -- if you have, let me know your findings! I'd love to play more in this area too.
Russian Spindles are support spindles that maximize shaft weight -- they are all shaft, with a bulbous middle. These are used for spinning fine yarns from typically short fibers, as support spindles. Their support nature means they won't be pulling on the fibers as a drop spindle would; this allows very short fibers to be spun more easily. Their shaft-weight means they put twist into your fiber quickly, helping the short, fine fibers hang together as you spins them into yarn.
I've left out a ton of spindle makers, bottom whorl spindles entirely (but see below for a snippet on them), and a few spindle types -- but you're on information overload already, right? so I'll generously leave the possibilities for readers to comment.
Spindle shape, weight, and mass distribution are all part of the picture. But wait, there's more! Another controlling factor on spindle speed is how much speed you (the spinner) can impart to the spindle to set it spinning.
Here's the secret: snap the spindle at the skinniest point on the shaft, as far from the whorl/fattest point of the spindle as possible.
Why the skinniest point? Because you get more momentum from snapping at the skinniest appropriate space. I'm not going to overload you (or me!) with the physics, but the same force applied to a smaller diameter sets the spindle going at a faster pace. Or, if you want to keep things sedate at the start, snap at the widest point on the inch or so near the end of the shaft.
Why the farthest from the whorl? To give a more balanced spin. If you flick the spindle near the whorl, it is likely to wobble or at best gyroscope as it twirls. Imparting the spin further from it leads to a smoother spin.
With top whorl spindles primarily, but also bottom whorl spindles, you can roll the spindle on your thigh with the flat of your hand to get it going at speeds far higher than a finger-flick can impart. Yes, if you barber-pole the yarn up the shaft of a bottom whorl, this also works with them! huzzah!
Also, the next time you are plying, try this method: roll the spindle between your two palms and then set it free -- it will almost fly out of your hand, taking the yarn to be plied and twisting like mad. Be ready to draft more plying yarn out! This will go quickly, and it will be time to wind-on before you know it. Abby F. has a great YouTube video of this:
Finally, your spindle needs to be balanced. There's a great tutorial on checking and fixing spindle hooks at Hatchtown Farms. Basically, you need the yarn coming up from the spindle to be in a direct line through the center of the spindle when the spindle hangs from it. Adjusting the hook to make it so ensures a wobble-less spin. Bottom whorl spindles often have indentations below the tip; these hold the half-hitch to keep the yarn on the spindle, and reduce the wobble.
A little wobble does slow the spindle a bit, so carefully winding on to build an even cop as you spin also helps. The shape doesn't matter too much, a pyramid building up from the whorl or a football shape both tend to be stable on the shaft of the spindle. And on a Turkish spindle, you wind around the arms themselves, building a sphere of yarn.
I've touched on spindle physics briefly in this blog entry on spinning silk on spindles and you can see other spindle discussions in my Spindles Category.
And many thanks to Sarah for commenting on a previous post about spindles and sparking this post. This is something I've talked to alot of people about -- at spinning retreats, spin-ins, wool shows, and in many on-line forums; so it's great to sit down and think it all through for the blog.
<shameless plug>Yes, I sell all of the spindles pictured here, at The Bellwether and I'm also the author of Spindling: The Basics, the source of a lot more spindle information! Print out this blog entry and stuff it inside your copy as soon as it arrives (Grin!)</plug>
Do you have a favorite spindle? Why is it your favorite? Comment, email, or link-back a favorite spindle posting on your blog.
Wednesday, March 28, 2007
Spindle Physics, or, why some spindles are fast, some spin forever, and most are somewhere in between...