Bridge Mill Series Eliminates X-Axis Pitch/Yaw

The Johnford DMC-series double-column, moving-table bridge mill, available from Absolute Machine Tools, uses a one-piece Meehanite cast iron bridge/column assembly designed to take up less floor space than comparable C-frame VMCs. The series offers both moving-table and sliding-column (fixed-table) versions ranging from 36" × 36" × 30" to 60 × 20 ft. of travel.

These bridge mills have a long base casting with complete support of the table over the full 51" of Y-axis travel, accommodating large loads. The Y and Z axes hold fixed loads at all times while the X axis carries the only dynamic load, allowing for tight machining and tight tolerances during high-speed machining operations. The lack of table overhang eliminates X-axis pitch and yaw, and the minimized spindle centerline-to-column distance offers further rigidity. The machine’s heavily ribbed, cast iron construction also provides long tool life and part surface finish.

The combination of twin screw-type conveyors and a caterpillar conveyor ensures complete chip removal with little manual cleaning.

The large DMC 4000 series multi-axis machines can handle 44,000 lbs of table load with an X-axis travel of 118" to 236"; Y-axis travel of 110.2" to 189"; Z-axis travel of 31.5" to 42"; and W-axis travel of 39.4" to 78.7" on a fixed-column moving table. A variety of other machines are available in the DMC line as well.