Winders often use airshafts to drive the core. Airshafts include a central air-filled bladder which pushes lugs out radially in order to provide traction to the inside of the core. When the roll is complete, the airshaft bladder can be deflated so that it can be easily removed from the core.
One problem with airshafts is that the lugs can deform the core from its cylindrical shape. This may contribute to wrinkling at the start of a new roll. The bladder should be filled to the minimum pressure that will provide adequate traction for the running tension. The maximum traction will be required at large roll diameter.
Airshafts are hollow and the lugs take away strength. A common problem is the airshaft may sag under its own weight or when loaded with a large diameter roll. This may result in whipping or a resonance while running, perhaps at the highest RPM with core diameter or at a specific larger roll diameter. It may be necessary to use heavier steel airshafts as opposed to aluminum. In some circumstances, a larger diameter airshaft and core may be required.
Bladder lifetime is often an issue. Higher tension, small core diameter, larger roll diameter all contribute to larger forces acting to wear on the bladder. It may be necessary to replace with heavy-duty bladders.