Bridge Mills Machine Massive Parts
IMTS 2018: Available from Absolute Machine Tools, the Johnford DMC LH series of double-column, moving-table bridge mills are designed for the largest machined parts.
Beginning with a large Meehanite iron casting, every element of Johnford’s DMC LH series of double-column moving table bridge mills is designed for large-part machining. Available from Absolute Machine Tools, the machines offer X-axis travels ranging from 122" to 244" (3100 to 6100 mm) in 39.4" (1 meter) increments. The Y axis measures 110" (2800 mm), and the Z-axis travel is 32". Z-axis travels measuring 42" and 60" are also available.
A long base casting supports the table over the full X-axis travel, enabling machining of very large loads. The Y and Z axes hold fixed loads, while the X axis carries dynamic loads. This facilitates tight machining and tight tolerances during high-speed machining operations. Without table overhang, X-axis pitch and yaw are eliminated. The spindle centerline-to-column distance is minimized, contributing to rigidity. The machine’s ribbed cast iron construction improves tool life and part surface finish. The combination of surround-table guarding with twin screw-type conveyors and a caterpillar conveyor contributes to chip removal and reduces the need for manual cleaning. Finite element analysis is used to design each bridge mill, simulating the effects of real-world conditions, including vibration, heat, fluid flow and other physical impacts.
The DMC-3100LH, 4100LH, 5100LH, and 6100LH all feature rigid boxways in Y and Z and Schneeberger roller ways in X to increase carrying capacity. Two-speed, gearbox-driven, 35-horsepower spindles provide heaving cutting power and torque. Spindles with 50 horsepower are available. A 40-tool automatic toolchanger (with 60, 80 and 120 options available) facilitates rapid tool changing.
Old-world craftsmanship combines with precision machining on a vertical machining center and Swiss-type lathe to produce some of the only U.S.-made mechanical wristwatch movements.
... not to mention grinding with air. Thanks to high speed spindles powered by shop air, this job shop expands the work its VMCs can do.
At IMTS 2014, you’ll see that a familiar U.S. machine tool brand is back.