List the variety of charkhas used now days
Answers
Double Drive:The drive band passes round the wheel and spinning head twice. The bobbin and the whorl are each independently turned. Since the bobbin pulley is smaller than the flyer pulley, the flyer turns faster, both twisting the yarn and winding the yarn on the bobbin. The amount of twist in the yarn depends on the difference between the ratios of the pulley and flyer as well as the extent the bobbin is allowed to slip by the drive band. A slack drive band prevents the yarn winding on the bobbin.
Single Drive, flyer lead; (Scotch Tension)
A single drive band controls and turns the flyer either through a separate whorl at the bobbin end of the flyer, or a whorl built onto the orifice end of the flyer. The bobbin is dragged round by the yarn and held back by the friction from the brake band. The tension on the brake band is adjustable to vary the ease with which the bobbin slips and twist builds up in the yarn. Relaxing the pull on the yarn allows it to build up on the bobbin.
These generally show very high ratios of 40:1 in the Great Wheel, and up to 250:1 with a Miner's head to multiply the action. The Charka, developed to spin Indian cotton which has a short fibre length, can provide a drive ratio of over 150:1, giving strong yarns and a rapid rate of production.
Single drive, Irish Tension mechanismThis configuration is the opposite of the scotch tension, with the drive band turning the bobbin. The yarn linking it to the bobbin drags the flyer round. The flyer is held back by an adjustable brake band allowing the yarn to wind on the bobbin; by restraining the wind on, the spinner builds up the twist.