Speedy alignment

When loading a toolholder into a machine tool spindle with an automatic toolchanger, misalignment of the ATC gripper to the spindle can damage the spindle taper. In addition, a misaligned, clamped toolholder increases cutting tool runout.

Machine tool builders align the spindle to the gripper using a plug gage that fits though holes in the V-groove, or ATC, plug and the taper plug. But they have difficulties when the plugs are out of alignment because they don’t know which direction to move the gage to correct the misalignment, according to Jack Burley, vice president of sales and engineering for BIG Kaiser Precision Tooling Inc. “There’s a lot of trial and error,” he said.

Courtesy of BIG Kaiser Precision Tooling

The ATC alignment tool from BIG Kaiser aligns a machine tool’s spindle and the ATC gripper.

To translate the direction in which the ATC arm is off and make adjustments without guessing the direction, BIG Daishowa Seiki Co. Ltd., Osaka, Japan, developed an ATC alignment tool, which BIG Kaiser supplies, to directly make adjustments according to a 10µm/div. dial indicator reading. In other words, the alignment tool’s dial indicator instructs a user which direction to rotate the 20mm shaft (AL plug) in order to align the taper plug (AL shank) and the ATC plug (AL flange).

The alignment tool has a stylus that determines the high and low values when the AL plug is slowly rotated.

To use the tool, the AL shank is first loaded in the machine and the AL flange is mounted on the ATC arm. The user then inserts the AL plug in the AL flange, rotates the plug and reads the highest and lowest values on the dial indicator. The plug is rotated in the eccentric direction, and half the gap between the high and low readings is the eccentric amount. Such eccentricities would be otherwise imperceptible, the company reports.

Lastly, the user adjusts the position of the ATC arm so the front end of the AL plug can be fully inserted into the AL flange. Alignment takes about 10 to 15 minutes, Burley noted.

In addition to selling the tool to machine builders, BIG Kaiser is targeting machine dealers who might have to tweak an ATC arm that went out of alignment during transportation and end users who perform their own machine maintenance. “If you have a lot of machines and it’s common to see a misalignment, then the tool makes sense,” Burley said, noting that a machine might require adjustment every 3 to 5 years.

The ATC alignment tool costs about $2,000 and can also align the ATC gripper to magazine tool pockets.

For more information, contact BIG Kaiser Precision Tooling Inc., Hoffman Estates, Ill., at (847) 228-7660 or www.bigkaiser.com. CTE