The adjustable speed bench grinder's speed can be controlled through a variety of mechanisms, including: Many grinders feature a dial or knob that allows the operator to manually set the desired speed. This is a straightforward method that provides immediate feedback and control. Some advanced models incorporate digital control panels that offer precise speed settings. These panels often include digital displays that show the current speed, providing a high degree of accuracy. In more sophisticated setups, VFDs are used to regulate the motor's speed. These systems offer a wide range of speed adjustments and can be programmed for specific tasks. The speed at which the adjustable speed bench grinder operates has a direct influence on the grinding process. Here are some of the effects that different speeds can have: Higher speeds generally thereby a faster material removal rate, which can be beneficial for rough grinding or when working with softer materials. https://www.tzqhjindustry.com/product/concrete-vibrator/High-Speed-Electric-Bench-Grinder-Power-Tool-for-Efficient-Grinding.html