DODGE CITY, KS—Curtis Machine, a manufacturer of gearboxes for agricultural, printing and food processing machinery, is building a new assembly plant here.

FAIRLESS HILLS, PA—Gamesa Technology Corp. completed and shipped its 1,000th nacelle assembled at its factory here.

PEORIA, IL—Caterpillar Inc. won’t choose its home state of Illinois as the site of its new $150 million assembly plant, citing the state’s “unfriendly” business climate.

BROWNSVILLE, TX—Precision Coils is investing $3.7 million to renovate an old assembly plant here to improve production of its heating and cooling coils.

A Siemens gas turbine is 36 feet long and weighs 280 tons—and yet its parts are machined to tolerances of a few thousandths of an inch. ASSEMBLY magazine's editor-in-chief goes behind the scenes to see how this engineering marvel is made.