HMCs are built for rigidity and accuracy

Helping to reduce non-cut time, the DHM 630 delivers a rapid traverse rate of 945 ipm in the X, Y and Z axes.

Doosan Infracore's DHM series of horizontal machining centers combines high-torque spindles, axis drives, rigid castings and solid boxways to deliver deeper cuts at faster speeds without jeopardizing precision or surface finish.

Known as the Diamond Series, these HMCs come in three models (DHM 500, DHM 630 and DHM 800) to handle an array of products.

The machines come standard with two rotary pallets and an automatic pallet changer. The pallet is positioned by four tapered cones and a large diameter curvic coupling for position accuracy. In addition, a standard 60-tool capacity automatic, bi-directional tool changer with optional capacity for 90,120, 180, and 240 tools accepts 50 taper tools to a maximum weight of 55 lbs. The ATC is separated from the machine body, and fully protected from chips and coolant. A foot switch releases the tool, making manual loading of the bidirectional magazine quick and easy. Furthermore, tools in the magazine can be changed safely during operation.

Fine-grained meehanite castings provide excellent dampening characteristics and the bed and box-type column are ribbed to withstand extreme cutting forces. In addition, each axis is driven by a high-precision ballscrew centered between the guideways. The ballscrews are supported at each end with angular thrust bearings. Ac cording to the company, this double pretension design deliv ers ±0.00008-in. repeatability. There is also a 50mm diameter ballscrew which connects direct ly to the Fanuc AC servo drive motor. With no gears or belts, backlash and servo lag is elimi nated. A standard rigid tapping function allows synchronized, high-speed tapping with a stan dard collet chuck. This elimi nates the need for special tap holders.

Options include a 0.001° NC rotary table, auto tool length measuring system, glass scales and test bar, to name a few.

The DHM 500 travels 31.5 in. in the X-axis and 25.6 in. in both the Y and Z-axes. Table load capacity amounts to 1,764 lbs. and the pallet size is 19.7 in. x 19.7 in. With table movement of 39.4 in. x 31.5 in. x 33.5 in. in the X, Y and Z-axes, respectively, the DHM 630 handles a table load capacity of 2,640 lbs. on a 24.8 in. x 24.8 in. pallet. The DHM 800 delivers X, Y, Z movement of 49.2 in. x 39.4 in. x 39.4 in., respectively, and is designed to accommodate a table load capacity of 3,520 lbs. with a pallet size of 31.5 in. x 31.5 in. All three machines maintain a positioning accuracy of ±0.0002 in./full stroke.