The test piece should be located in the middle of the X stroke and along the Y and Z axes in the appropriate position for the test piece and fixture positioning and tool length. When there are special requirements for the positioning position of the specimen, it should be specified in the agreement between the manufacturer and the user.
2. Fixing of specimen:
The test piece should be easily installed on a dedicated fixture to achieve maximum stability of the tool and fixture. The mounting surface of the fixture and specimen should be straight.
The parallelism between the mounting surface of the specimen and the clamping surface of the fixture should be tested. A suitable clamping method should be used so that the tool can be penetrated through and machined the full length of the center hole. Countersunk screws are recommended to fix the specimen to avoid tool and screw interference, or other equivalent methods can be used. The total height of the specimen depends on the fixation method chosen.
1. Positioning of vertical machining center specimen:
The test piece should be located in the middle of the X stroke and along the Y and Z axes in the appropriate position for the test piece and fixture positioning and tool length. When there are special requirements for the positioning position of the specimen, it should be specified in the agreement between the manufacturer and the user.
2. Fixing of specimen:
The test piece should be easily installed on a dedicated fixture to achieve maximum stability of the tool and fixture. The mounting surface of the fixture and specimen should be straight.
The parallelism between the mounting surface of the specimen and the clamping surface of the fixture should be tested. A suitable clamping method should be used so that the tool can be penetrated through and machined the full length of the center hole. Countersunk screws are recommended to fix the specimen to avoid tool and screw interference, or other equivalent methods can be used. The total height of the specimen depends on the fixation method chosen.
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3. Material, tool and cutting parameters of the specimen:
The materials, cutting tools and cutting parameters of the test pieces are selected according to the agreement between the manufacturer and the user, and should be recorded. The recommended cutting parameters are as follows:
1) Cutting speed: cast iron is about 50m/min; Aluminum parts are about 300m/min.
2) Feed rate: about (0.05~0.10) mm/ tooth.
3) Cutting depth: the radial cutting depth of all milling operations should be 0.2mm.
4. Size of the specimen:
If the specimen is cut several times, the outline size is reduced, and the aperture is increased, when used for acceptance inspection, it is recommended to choose the final contour machining specimen size consistent with that specified in this standard, so as to truthfully reflect the cutting accuracy of the machining center. The test pieces can be used repeatedly in cutting tests and their specifications should be kept within 10% of the characteristic dimensions given in this standard. When the specimen is used again, a thin layer cutting should be performed to clean all surfaces before a new fine cutting test is carried out.
When the dynamic tracking error is too large and the alarm, you can check: servo motor speed is too high; Whether the position detection element is good; Position feedback cable connector is in good contact; Whether the corresponding analog output latch and gain potentiometer are good; Whether the corresponding servo drive device is normal.
If the machining accuracy is not good due to overshoot when the machine tool is moving, the acceleration and deceleration time may be too short, and the speed change time can be appropriately extended; It may also be that the connection between the servo motor and the lead screw is loose or too rigid, which can appropriately reduce the gain of the position ring, which may be the roundness of the two-axis linkage, and this deformation may be caused by the mechanical adjustment. The positioning accuracy of the shaft is not good, or the lead screw gap compensation is improper, which will lead to roundness error when it crosses the quadrant.