Common Types and Functions of Tool Setters

Ⅰ. Types of tool setters

1. High Precision Removable Arm （HPRA）

The characteristic of HPRA is that the tool arm and base can be separated. When in use, the tool arm is installed on the base of the tool setter through the plug-in mechanism. When the electrical signal is connected, it is in working condition; after use, the tool arm can be pulled out from the base and placed in a suitable place in order to protect the precise tool arm and probe from dust and collision damage. This kind of tool setter is suitable for small CNC lathes.

2. High Precision Pulldown Arm（HPPA）

The characteristic of HPPA is that the tool arm and the base are connected in rotation, which is  integrated. Swing and pull the tool arm out of the protective cover when in use, and retract the tool arm into the protective cover when not in use, so there is no need to worry about it being damaged during processing. And there is no need to insert and remove the tool arm frequently, avoiding bumps caused by frequent insertion and removal.

3. High Precision Motorised Arm（HPMA）

The characteristic of HPMA is that the tool arm and base realize the swing out and swing back of the tool arm through a torque motor. The difference from HPPA is the addition of a torque motor, which improves the degree of automation. More importantly, the swing out and swing back of the tool arm can be programmed into the processing program through M code. During the processing cycle, the automatic measurement and compensation of the tool wear value and the monitoring of tool damage can be easily realized. And cooperated with automatic loading and unloading mechanism, unmanned processing achieves.

4. High Precision Automatic contact

Once the horizontal and vertical positions of the worktable have been found for installation, automatic tool setting can be effectively achieved by entering the program within the corresponding CNC system. It plays an essential role in the development of carving and glass machines in China.

Ⅱ. Functions of Tool Setters

Do you know what does a tool setter do? Here are functions of tool setters.

1. Measuring and compensating tool deviation in five directions of ±X, ±Z and Y axis

Measuring and compensating the tool deviation in five directions can effectively eliminate the error and low efficiency of manual tool alignment. The machine tool with the tool setter can automatically set the offset value of the tool to the workpiece coordinate system, so as to automatically establish the workpiece coordinate system. In this case, there is no need to use G50 instruction to establish the workpiece coordinate system.

2. Automatic monitoring, alarm and compensation of tool wear or breakage during machining

It is very difficult to complete the compensation of the wear value on the machine tool without the tool setter. It is necessary to stop the machine tool for many times to manually measure the size of the workpiece, and the obtained wear value should be manually modified. After installing the tool setter, this problem is much simpler, especially after installing HPPA or HPMA. The former, as long as the machine tool is stopped after a certain number of workpieces are dried according to the law of tool wear, and the tool setting process is performed again with the tool setter; the latter, as long as the number of machining cycles is set in the program to be executed.

For tool breakage alarm or tool replacement after tool wear reaches a certain degree, a threshold value is set according to the allowable wear of the tool. Once the error monitored by the tool setter exceeds the threshold value, that is, the tool is considered to be damaged or exceeds the allowable wear value, the machine tool automatically alarms and stops, and then forces the tool replacement.

3. Compensation of tool deviation variation caused by thermal deformation of machine tools

During the working cycle of the machine tool, various heat generated leads to the deformation of the machine tool, especially the thermal elongation of the screw, which changes the position of the tool tip. The result is that the dimensional accuracy of the workpiece will be affected. The above problems can be solved by installing the tool setter on the machine tool. All this is to regard the change of the tool tip position caused by thermal deformation as the wear value of the tool, which can be solved by measuring the tool deviation with the tool setter.