Dressing
Application
The term "dressing" refers to the sharpening or truing up of a grinding tool inside the machine. During dressing, the dresser machines the grinding wheel. Thus, during dressing, the grinding tool is the workpiece.
Related topics
- Activating dressing mode with FUNCTION DRESS
- Cycles for dressing
- Parameters for dressing tools
- Jig grinding
- Cylindrical grinding
Requirements
- Grinding (#156 / #4-04-1) software option
- Available kinematics description for jig grinding
The machine manufacturer creates the kinematics description.
Description of function
In dressing, the workpiece datum is located on an edge of the grinding wheel. Select the respective edge using Cycle 1030 ACTIVATE WHEEL EDGE.
During dressing, the axes are arranged such that the X coordinates describe positions on the radius of the grinding wheel, and the Z coordinates describe the positions along the axis of the grinding wheel. The dressing programs are thus not contingent on the machine type.
The machine manufacturer defines which machine axes will perform the programmed movements.
The dressing operation removes material from the grinding wheel and may cause wear of the dressing tool. The material removal and wear lead to changed parameters that need to be compensated for after dressing.
The COR_TYPE parameter provides the following compensation options:
- Grinding wheel with compensation, COR_TYPE_GRINDTOOL
Compensation method with material removal at grinding tool
- Dressing tool with wear, COR_TYPE_DRESSTOOL
Compensation method with material removal at dressing tool
Grinding tool table toolgrind.grd (#156 / #4-04-1)
Use the Cycles 1032 GRINDING WHL LENGTH COMPENSATION and 1033 GRINDING WHL RADIUS COMPENSATION to compensate for the grinding wheel or the dresser, regardless of the compensation method.
Cycle 1032 GRINDING WHL LENGTH COMPENSATION (#156 / #4-04-1)
Cycle 1033 GRINDING WHL RADIUS COMPENSATION (#156 / #4-04-1)
Dressing a grinding wheel edge shape
You can define a grinding wheel edge shape for the following types of grinding tools:
- Cylindrical grinding pin
- Straight wheel
Shape of the grinding wheel face
The control provides the following possibilities for dressing the defined grinding wheel edge shape:
- Only the front face or shaft face with Cycle 1011 DRESSING SIDE A/I
- Front face or shaft face and diameter with Cycle 1012 DRESSING D AND A/I
Simplified dressing with a macro
Refer to your machine manual.
The machine manufacturer can integrate a macro in the dressing cycles. The macro handles, for example, selection of the dressing mode FUNCTION DRESS and the grinding wheel edge, and also the TOOL CALL for the dressing tool. In this case, the machine manufacturer determines the dressing sequence.
Compensation methods
Stock removal on the grinding tool
During dressing, a dressing tool is usually used that is harder than the grinding tool. Due to the difference in hardness, the stock removal during dressing mainly takes place at the grinding tool. The programmed dressing amount is actually removed at the grinding tool, since the dressing tool does not noticeably wear. In this case the compensation method Grinding wheel with compensation, COR_TYPE_GRINDTOOL is used in the COR_TYPE parameter of the grinding tool.
Grinding tool table toolgrind.grd (#156 / #4-04-1)
With this compensation method, the parameters of the dressing tool remain constant. The control compensates only for the grinding tool:
- Programmed dressing amount in the basic data of the grinding tool (e.g., R-OVR)
- If applicable, measured deviation between nominal and actual dimension in the compensation data of the grinding tool (e.g., dR-OVR)
Stock removal on dressing tool
In contrast to the standard situation, stock removal does not take place only on the grinding tool in certain grinding and dressing combinations. In this case the dressing tool wears noticeably (for example, with very hard grinding tools in combination with softer dressing tools). To compensate for this noticeable wear on the dressing tool, the control offers the compensation method Dressing tool with wear, COR_TYPE_DRESSTOOL in the COR_TYPE parameter of the dressing tool.
Grinding tool table toolgrind.grd (#156 / #4-04-1)
With this compensation method the parameters of the dressing tool change significantly. The control compensates for both the grinding tool and the dressing tool:
- Dressing amount in the basic data of the grinding tool (e.g., R-OVR)
- Measured wear in the compensation data of the dressing tool (e.g., DXL)
If you use the compensation method Dressing tool with wear, COR_TYPE_DRESSTOOL, the control stores the tool number of the dressing tool used in the T_DRESS parameter of the grinding tool after dressing. During future dressing processes, the control monitors whether the defined dressing tool is used. If you use a different dressing tool, the control interrupts the dressing with an error message.
You must recalibrate the grinding tool after each dressing process so that the control can determine and compensate for the wear.
Notes
- For dressing operations, the machine must be prepared accordingly by the machine manufacturer. The machine manufacturer may provide his own cycles.
- Measure the grinding tool after dressing so that the control enters the correct delta values.
- Not all grinding tools require dressing. Comply with the information provided by your tool manufacturer.
- When using the Dressing tool with wear, COR_TYPE_DRESSTOOL correction method, inclined dressing tools must not be used.
- When dressing a grinding wheel with relief cut, the angle of infeed Q1023 must be equal to or greater than the relief cut. If you program a smaller angle of infeed, the grinding wheel will lose dimensional accuracy.
- Dress the grinding tool either before or after a cylindrical grinding operation.