Danger comes from the fact that centrifugal 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 dremeldrillpress 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 dremeldrillpress example, consider the same wheel with a maximum safe operating speed of 6,600 rpm run on a 5-inch right angle grinder at 10,000 rpm. This represents an over-speed of about 1.5 times the wheel''s designed speed. But the corresponding centrifugal force-and the corresponding rotational stress on the wheel-would be about 2.3 times as much as the maximum allowed.

For dremeldrillpress utilization and geographic location, ODS-Petrodata''s November Offshore Rig Locator shows 264 jackups working, out of a total worldwide fleet of 388 rigs, for 68% utilization, down from 82% one year ago. This is principally due to sharp cuts in the U.S. Gulf of Mexico, where only 72 of 150 available units were working due to lower oil/gas prices. The second most active area was the Persian Gulf, with 46 of its 56 rigs working. The North Sea/NW Europe had all but one of its 34 jackups working. Asia accounted for 60 rigs--in India, 16 of 20 units were working; SE Asia had 19 of its 22 rigs active; and the Far East saw 11 of its 18 jackups working. West Africa was working 19 of its 23 rigs. Other active areas included: the Mediterranean/Black Sea, 10 of 12; Red Sea/Gulf of Suez, 11 of 11; and South/Central America, 18 of 25.

As the stay-at-home dremeldrillpress mom, I am drawn rapidly into Riley''s new interest. And after a brief initial hesitation, I plunge willingly and headlong into the world of the construction site. Riley''s excitement is infectious, and I find myself making detours so we can watch a forklift or excavator at work. In the dremeldrillpress car, he practically levitates out of his seat with joy when we pass a backhoe. "Mo''! Mo''!" he shouts. I try to explain that I can''t conjure earthmovers at will. But I suspect he thinks I''m being stingy. We buy a toy dump truck at a yard sale, and a relative in Illinois sends a nifty scale model of a John Deere tractor wheel loader.

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