The new EC-400 HMC is a T-base horizontal machining center with a work cube of 20" × 20" × 20", a dual pallet changer with 400-mm pallets and a built-in rotary indexer. The HMC comes standard with an 8,000-rpm, 40-taper spindle powered by a 20-hp vector dual drive system. Also standard are a side-mount tool changer (24+1 tools), 945-ipm rapids and a high-volume coolant system. To eliminate downtime associated with manual chip removal, the HMC is equipped with a triple-auger chip conveyor system that the company says removes chips from the enclosure quickly and efficiently.
A 12,000-rpm spindle powered by a 30-hp vector dual drive system is available as an option. This spindle provides additional horsepower for heavy cuts, as well as 50 percent more speed for high speed machining operations, the company says. Both spindles feature an inline, direct-drive system that couples the motor directly to the spindle rather than using belts or gears. According to the company, this results in less vibration, less heat and less noise than other drive systems, which is said to provide better surface finishes, thermal stability and quiet operation. On-the-fly wye-delta switching provides low-end torque and a wide constant-horsepower band, without having to stop the spindle to change windings.
The HMC comes standard with a pallet indexer that provides 45-degree incremental indexing for multi-sided tombstones. For accurate positioning of multi-faceted parts, a high-precision face-gear indexer with 1-degree indexing is available as an option. A full fourth-axis rotary table is also available for shops requiring simultaneous four-axis motion, and a fifth axis can be added for complex work.
The servo-driven pallet changer on the HMC swaps pallets in 10 seconds, and each 400-mm pallet has a load capacity of 1,000 lbs. A separate load station allows the operator to safely load/unload parts or change fixtures on one pallet while parts are being machined on the other, keeping spindle run time at a maximum, the company says.
The HMC comes standard with a side-mount tool changer that holds 24 tools plus one in the spindle. A double-arm gripper swaps tools in 2.8 seconds. To reduce cycle times further, a high speed, servo-driven SMTC (also 24+1 tools) is available; the company says it reduces tool-to-tool times to 1.6 seconds. A 40-pocket side-mount is also available if additional tool capacity is needed.
HMC for Large Aerospace Parts
Okuma’s MA-12500HW horizontal machining center is designed to provide a balance of speed and cutting power in difficult materials like cast iron and aluminum alloys.