Maintenence
mood: 
anxious
anxiousNow this may not seem like too much fun for many ~ but the engineering in creating a spinning wheel facinates me and this is a chance to take them all apart and wonder at the workings!
THis article may explain it better! Don't fall asleep now!
Ask different spinners and you will get different opinions on which is best, so let's start with the difference. A single drive wheel has the drive band going once around the wheel and the flyer and has a separate brake on the bobbin or flyer. This is also known as the Scotch tension braking system. A double drive wheel uses a drive band that is longer, as it goes around the wheel, to the bobbin, back around the wheel again then around a whorl on the flyer. Some wheels come one way, others the other way, sometimes you can get both (kind of...). Sometimes you get to choose (Ashford Traveller and Traditional). So what is the big deal?
Most beginners will find the Scotch tension system easier to understand and master. Both the brake and the drive band can be adjusted separately so control of twist and take-up are easier. The double drive system provides a firmer, more consistent yarn and with normally higher ratio options. If the wheel you like is a double drive wheel, see if it comes with a Scotch tension single drive option; this gives you freedom to use both.
The Technical Information - Single vs. Double drive
Single drive wheels have the drive band going around the wheel one time. The drive band will then go around the drive pulley on the flyer (some manufacturers have the band drive the bobbin, not the flyer; Ashford, Lendrum, Majacraft and Kromski Prelude drive the flyer, Louet drives the bobbin). The rotation of the wheel causes the flyer to rotate and depending on the difference between the diameter of the wheel and the diameter of the flyer pulleys, you develop a ratio between the two. A brake band (sometimes called Scotch tension) with a spring attached, is placed over a pulley built into the bobbin (this brake is on the flyer for Louet wheels) and the tension is adjusted. This information applies to nearly all single drive spinning wheels built today, regardless of brand.
Double drive wheels also use one drive band but it goes around the wheel twice (you make a double loop of the drive band to do this). At the flyer, the two loops of the drive band do two different things: one of the loops will go around the whorl (the whorl will have one or two grooves of different diameters - your ratios are established here with the whorl. Whorls are located at the rear of the flyer and are removable so you can change the ratio of the drive; the whorl must be removed to change the bobbin); the other loop will go around a pulley located at the end of the bobbin. This information applies to nearly all double drive spinning wheels built today, regardless of brand.
How they work
Spinning takes place in the following manner: the main wheel drives (rotates) the flyer/bobbin by means of the drive band. Tension on the drive band is adjustable and you set it to make sure there is no slip at the flyer/bobbin. You treadle, the wheel turns, the flyer and bobbin rotates) and twist is imparted to the fibers in your hand. In order for the yarn to get on the bobbin automatically, there must be, from time to time, a change in the speed of the bobbin. It must: slow down (be braked) on single drive wheels; speed up on double drive wheels - so the flyer can facilitate wrapping the yarn around the bobbin. This is where the two methods diverge.
A single drive wheel has a separate dedicated band, a brake band (Scotch tension), around the bobbin or flyer . In order to facilitate the accumulation of yarn on the bobbin, the bobbin or flyer is "braked," or retarded, when: 1 - you have the proper tension on the brake band; 2 - you allow the twisted yarn in your hand to be pulled into the orifice of the flyer (the "take up"). On a single drive wheel, you have a way to adjust tension on the drive band (not really needed if using an elastic band) and a separate adjustment for the brake band/take-up control; adding tension to the brake increases the pulling force of the yarn from your hand. Ideally your want a gentle pull that quickly gets the yarn on the bobbin.
On a double drive wheel, there is no separate brake band but rather one of the loops of the drive band will cause the bobbin to rotate while also slipping during spinning while the other loop drives the flyer. The shape of the whorl grooves (V-shaped) results in positive drive of the flyer all the time while a different shape of the groove on the bobbin pulley (U-shaped) allows "slippage" of the bobbin while you add twist to your fiber. While spinning, the bobbin slips on the drive band to allow the bobbin to rotate in sync with the flyer. When you allow the yarn to be pulled into the orifice you are letting the bobbin gain speed (less sliipping) in relationship to the flyer arms causing yarn to be wrapped on the bobbin. This all works if: 1- your tension is set correctly; 2 - you allow the twisted yarn in your hand to be pulled into the orifice of the flyer. The tension adjustment affects both the drive of the flyer and the slipping of the bobbin, so one adjustment must result in good performance of drive and take-up. This is not difficult to do. Also note that for a double drive flyer to effect take-up the pulley on the bobbin must be smaller than the whorl. Never match a small whorl with a bobbin pulley that is larger.
A - Wheel
B - Drive Band
C - Flyer assembly
D - Maiden
E - Bearings
F - Tension Screw
G - Treadle
H - Footman
I - Treadle connection
J - Treadle bar
K - Table
L - Distaff
In addition to all this fun and science ~ I get to rub down rare woods and watch the grain glow as the years pass. And drool as I wait for 12th night!!!
