Danger comes from the fact that centrifugal 2airsander force does not increase in direct proportion to an increase in speed, but instead it increases as the square of that speed increase. When rotational speed doubles, centrifugal force quadruples. This effect means that relatively small changes in speed can produce significant increases in force. In the example mentioned, changing from 6,600 rpm to 7,700 rpm multiplies the speed by 1.167. However, the corresponding centrifugal force would multiply by a factor of 1.167 x 1.167, or 1.36. To take a more extreme example, consider the same wheel 2airsander with a maximum safe operating speed of 6,600 rpm run on a 5-inch right angle grinder at 10,000 2airsander rpm. This represents an over-speed of about 1.5 times the wheel''s designed speed. But the corresponding 2airsander centrifugal force-and the corresponding 2airsander rotational stress on the wheel-would be about 2.3 times as much as the maximum allowed.

In short, never over-speed a grinding wheel. The speed of the grinder must be compared to the speed marked on the wheel or package to make sure the machine''s speed is at or below the maximum operating speed of the wheel. Surpassing this rating risks not just 2airsander and 2airsander wheel breakage but also the safety of shop personnel. About the author: Roger Cloutier is a senior product safety engineer for the Norton Abrasives brand of Saint-Gobain Abrasives in Worcester, Massachusetts.

©2003 www.airsanders.com. All rights reserved.