CNC machining, tool setting is a critical step to ensure machining accuracy and efficiency. The following are seven common methods of tool setting, these methods are essential skills for CNC machinists:
1. test cut tool setting method
Features: simple and convenient, but will leave cutting marks on the surface of the workpiece, tool setting accuracy is low.
Steps:
Workpiece clamped on the worktable, leaving the position of the tool setting.
Start the spindle rotation, move the table and spindle quickly to make the tool close to the workpiece.
Use the fine-tuning operation to bring the tool into contact with the workpiece and record the coordinate values in the machine’s coordinate system.
Back off the tool and approach the other side of the workpiece in the same way and record the coordinate values.
Calculate the coordinates of the origin of the workpiece coordinate system in the machine coordinate system.
For z-direction tool setting, make the end face of the tool touch the upper surface of the workpiece in the same way and record the z value.
The measured x,y,z values are entered into the machine tool coordinate system memory address, and run to make it effective.
2. Plug rule, standard mandrel, block gauge tool setting method
Characteristics: the spindle does not rotate, will not leave traces on the surface of the workpiece, but the accuracy of tool setting is not high.
Steps: similar to the test cut tool setting method, but add a plug ruler, standard mandrel or block gauge between the tool and the workpiece, subject to the plug ruler can not be freely pumped, the thickness of the plug ruler is subtracted from the calculation of coordinates.
3. Edge Finder, Eccentric Bar and Shaft Setter Tools for Tool Setting Method
Characteristics: the most commonly used method, high efficiency, high precision tool setting.
Steps: The procedure is similar to the test cut method, replace the tool with an edge finder or an eccentric bar. Be careful when using the edge finder, so that its steel ball part and the workpiece slight contact.
4. Transfer (indirect) tool setting method
Characteristics: Suitable for multi-tool machining, especially when the zero point is machined off or not allowed to damage the machined surface.
Steps:
Make a test cut or plug rule tool setting for the first tool, and record the machine coordinates of the workpiece origin.
Using a tool setter, contact the tip of the first tool with the tool setter, record the number and zero the relative axes.
Do the same for the second tool and record the values corresponding to the relative coordinates of the axes.
Add the coordinate data of the first tool to the relative coordinate value of the second tool to get the zero coordinate of the second tool and enter it into the machine tool.
5. Top tool setting method
Characteristics: Applicable to x,y direction tool setting, especially when the workpiece has a drawing line center point.
Steps:
Clamp the workpiece on the table and replace the top center.
Move the center of the workpiece close to the center of the drawing line, use the fine-tuning operation to align the center of the tip of the center point, and record the coordinate value in the machine coordinate system.
Remove the top, install the milling cutter, and use other methods to get the z-axis coordinate value.
6. Percentage table (or micrometer) tool setting method
Characteristics: Generally used for round workpiece tool setting, especially when the precision requirements are high.
Steps:
Install the percentage meter on the toolholder or spindle sleeve, move the table so that the spindle centerline moved to the center of the workpiece.
Adjust the meter contact to contact the circumference of the workpiece, slowly rotate the spindle by hand, and observe the pointer offset.
Move the table several times, until the spindle is basically in the same position when turning the meter pointer, at this time that the spindle center is the origin of the workpiece.
Remove the percentage table, install the milling cutter, with other tool setting methods to get the z-axis coordinates.
7. Automatic tool setting method
Characteristics: realized by the tool tip detection system, high degree of automation, high precision tool setting.
Steps:
The tool tip approaches the contact sensor at a set speed.
When the tip of the tool comes into contact with the sensor and sends out a signal, the CNC system immediately notes down the coordinate value of the instant.
The system automatically corrects the tool compensation value and completes the tool setting.
Each of these seven tool setting methods has its own characteristics and is suitable for different machining scenarios and workpiece requirements. CNC machinists should choose the most appropriate tool setting method according to the actual situation to ensure machining accuracy and efficiency.
