Why Use a Safe Driver?
A spindle held between a spur and live center can be a potentially hazardous situation. When using a gouge or a skew, a work piece held using this method can catch, become dislodged, or cause injury to the turner due to the unforgiving nature of the biting teeth of a spur. A Safe Driver can help to avoid these potentially dangerous situations. Using a Safe Driver encourages good tool control when training because a catch or heavy handedness merely safely stops the piece being turned. When turning large and heavy spindle type components, make sure you increase the amount of tension in the spring.
Safe Drivers are mounted in the headstock of machines, with a Live Center in the tailstock. Pressure between the headstock and tailstock allow the wood to turn. Because there are no aggressive teeth on the Safe Driver (as there are on Spur Drivers), if the turner gets a catch while working, the wood merely stops spinning while the Safe Driver keeps turning. Avoiding catches in this way allows a turner to work with much more confidence.
Safe Drivers are also excellent tools when turning spindles that the turner wishes to flip around while working on them (switching the work piece so that the headstock end becomes the tailstock end). The machine does not have to be stopped to perform this operation. Merely loosening the tailstock pressure allows the piece to stop spinning so it can be flipped over. Tightening tailstock pressure will then start the piece spinning again.
Note: The #1 Safe Driver and the #2 Safe Drivers with the 3/8″ or 5/16″ through hole are not spring loaded and do not contain a point.