In a lathe machine, what function does the feedwheel serve?

The feedwheel in a lathe machine plays a crucial role in controlling the feed of the cutting tool. This means that it determines how much the cutting tool advances into the workpiece with each rotation of the spindle. By adjusting the feedwheel, the operator can set the rate at which the tool moves in relation to the workpiece, which subsequently influences the depth of cut, surface finish, and overall machining efficiency. The accurate control of this feed rate is essential for achieving the desired dimensions and quality on the machined part.

In contrast, the other options pertain to different functions within the lathe. The spindle's speed is managed by a separate mechanism designed to adjust the rate at which it rotates; it does not rely on the feedwheel. Providing power to the cutting tool involves the lathe's motor and drive system, not the feedwheel, which primarily focuses on movement rather than power delivery. Similarly, disengaging the power supply is a safety feature that operates independently from the feedwheel and is involved in shutting down operations rather than controlling tool movement during machining.