This chart is for a drill press with a three pulley and two belt configuration.
In the table below the spindle pulley is labeled from top to bottom with the letters D, C, B, and A. Both the idler pulley and motor pulley are labeled from top to bottom with the numbers 4, 3, 2, and 1. For example, 140-RPM would have the configuration of A to 1 for the front belt. The belt would be in the lowest groove on the spindle pulley to the lowest groove on the idler pulley. The rear belt configuration is then 4 to 4 with the belt on the top grooves of the idler and motor pulleys. This chart is from Grisly but most drill presses are the same
RPM S=Spindle Pulley I=Idler Pulley M= Motor Pulley