Abstract: When a rotary table rotates, a main control section of a multi-tasking machine detects vibration of the rotary table on which a workpiece is mounted based on fluctuation of a position droop computed by a servo system. The main control section computes the arrangement position (the eccentricity amount and the eccentricity angle) of the workpiece with respect to the rotary table based on, for example, the detected vibration, the weight of the workpiece, and the rotation speed of the rotary table. The main control section computes the attachment position of a balancer with respect to the rotary table based on the computed arrangement position of the workpiece. Therefore, a suitable attachment position of a vibration suppressing balancer with respect to the rotary table is easily obtained.

Abstract: When a command radius r of a circular interpolation control exceeds a threshold value, a computer computes a speed limit for the circular speed at which the acceleration becomes constant. When the command radius r of the circular interpolation control is less than or equal to the threshold value, the computer 100 computes another speed limit for the circular speed at which r?3 or r?4 becomes constant, where ? is the angular frequency. The computer performs the circular interpolation control by safeguarding the circular speed from exceeding one of the speed limits in accordance with the command radius r of the circular interpolation control.

Abstract: When a rotary table rotates, a main control section of a multi-tasking machine detects vibration of the rotary table on which a workpiece is mounted based on fluctuation of a position droop computed by a servo system. The main control section computes the arrangement position (the eccentricity amount and the eccentricity angle) of the workpiece with respect to the rotary table based on, for example, the detected vibration, the weight of the workpiece, and the rotation speed of the rotary table. The main control section computes the attachment position of a balancer with respect to the rotary table based on the computed arrangement position of the workpiece. Therefore, a suitable attachment position of a vibration suppressing balancer with respect to the rotary table is easily obtained.

Abstract: When a command radius r of a circular interpolation control exceeds a threshold value, a computer computes a speed limit for the circular speed at which the acceleration becomes constant. When the command radius r of the circular interpolation control is less than or equal to the threshold value, the computer 100 computes another speed limit for the circular speed at which r?3 or r?4 becomes constant, where ? is the angular frequency. The computer performs the circular interpolation control by safeguarding the circular speed from exceeding one of the speed limits in accordance with the command radius r of the circular interpolation control.

Abstract: The surface of an aluminum alloy high-temperature processed article containing Mg is heated at a high temperature of 200° C. or above, thereafter the surface is etched with an aqueous solution containing a chelating agent, and then at least one surface treatment selected from hydration oxidation treatment, coating type chromating, coating, anodizing, and alternating current electrolysis in an aqueous alkali solution is further carried out. This method can provide a surface-treated aluminum alloy high-temperature processed article having superior anticorrosion and adhesion of coatings and a good surface appearance, and is effective as a pretreatment for further surface treatment.

Abstract: An aluminum material is surface-treated with an aqueous solution containing 0.005 mol/lit. or more of a chelating agent and 5 g/lit. or more of an organic amine and having 100 ppm or less of phosphoric acid radical ion concentration and 500 ppm or less of sulfuric acid radical ion concentration, until its surface has a color tone (S) of:S=(X.sup.2 +(3.388Z-3Y.sup.2).sup.1/2.gtoreq.70wherein X, Y and Z represent the tristimulus values of color.The aluminum material can be surface-treated while setting the treating conditions on the basis of a specific color tone detectable by colorimetry, without relying on experience and intuition. The surface-treated aluminum material can have a good anticorrosion, have good color change preventive properties, a good adhesion of coatings and a beautiful surface appearance.