Bridge Mill Series Increases Stability

The Johnford DMC series of double-column, moving-table bridge mills, available from Absolute Machine Tools, are built on a one-piece Meehanite cast iron bridge/column assembly. The machines are available in both moving table and sliding column (fixed-table) versions, ranging from 36" × 36" × 30" of travel to 60 × 20 ft. Configurations include multi-axis and five-face solutions; small-, medium- and large-frame constructions; and custom-made, unlimited-size, sliding double-column options.

The series has a long-base casting with complete support of the table over a 51" Y-axis travel, enabling the machining of large loads. The Y and Z axes hold fixed loads at all times while the X-axis carries the only dynamic load, enabling tight tolerances during high-speed machining operations. According to the company, X-axis pitch and yaw are eliminated because there is no table overhang. The spindle centerline-to-column distance is minimized, offering further rigidity. The machine’s ribbed cast iron construction is said to provide long tool life and quality surface finish.  The combination of twin screw-type conveyors and a caterpillar conveyor promotes complete chip removal with reduced manual cleaning.