The hazard of running man over-speed condition comes from centrifugal force. A result air of rotary motion, flo centrifugal force is what causes a weight on the end of a string sanders to pull the string air taught when the weight is swung flo in a circle. This same sanders force causes air the mass of the grinding wheel to be pulled outward flo from sanders the center of rotation as the wheel is spinning.

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

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