CNC Machining Programming: Best Practices and Standards for Mold Industry
The CNC programming department at the mold factory establishes clear processing technologies and standards, ensuring standardized operations throughout the production process to enhance work efficiency and minimize errors.
1. Front mold core
1. Hot nozzle position
- The dimensions with assembly requirements must be accurate according to the number.
- Plane: The processing program is based on the dimension number, and the CNC operator calibrates the table and measures the number according to the drawing’s size tolerance.
- Side: The processing program initiates compensation, leaving a 0.02 mm margin on one side for trial fitting. The operator uses a pin gauge to ensure a tight fit, while the tolerance allows for a variation of 0.015 to 0.005 mm on that single side. All other dimensions are derived from the numbers specified in the 3D drawing.
2. Insert buckle position
The insert buckle position must be processed following the specified procedure, ensuring the dimensions are accurate. The depth (Z value) of the insert buckle position should match the size specifications precisely. The operator will use a calibration table to measure the depth, which must have a tolerance of 0.01 mm.
3. Glue position size
The finishing process for all glue positions requires leaving 0.02mm on one side (except in special cases) and 0.15mm on one side for EDM pattern processing with spark pattern requirements.
4. Insertion and collision position
Typically, the front mold core is precise in size, while the rear mold core has a margin.
5. Edge lock
The bottom depth (Z value) of the edge lock is set to the standard size. The side processing program for the edge lock requires a compensation of 0.02 mm on one side for trial fitting. The operator will make adjustments based on the dimensions provided in the drawing, ensuring that the tolerance on a single side is maintained within the range of 0.005 to 0.015 mm.
2. Back mold core
1. Slider slot
The depth (Z value) of the slider slot should be determined based on the dimensions specified in the drawing. The operator uses a calibration table to measure this depth according to the drawing’s tolerances. Both sides of the slider slot must be machined to match the drawing size. During the programming process, a single compensation side should be opened with a margin of 0.02 mm for trial fitting. The operator then uses a block gauge to ensure a tight fit, with a tolerance maintained within the range of 0.015 mm to 0.005 mm on one side.
2. Insert buckle position
The position of the insert buckle must be determined based on the dimensions provided in the drawing. Additionally, the depth (Z value) at the bottom should be set according to these measurements. The operator will use a calibration table to measure the dimensions, ensuring that the tolerance for the depth is maintained at 0.01 mm.
3. Mold frame hole position (hidden CORE position)
The programmer needs to set a compensation of 0.02mm on one side when creating a light knife program. The compensation operator measures according to the dimensions specified in the drawing. The single-side gong is designed to be 0.005 to 0.01mm larger, which facilitates easier assembly.
4. Glue position size
All glue positions are finely processed with a margin of 0.02mm (except for special requirements).
5. Insertion and collision position
Under normal circumstances, the rear mold should have an additional margin for +0.02~0mm. The position of the rear mold core, which corresponds to the row position, should be determined based on the size number. Additionally, the row position that matches the rear mold core must also include this extra margin.
3. Mold core convex core
1. During rough machining, a 0.5mm margin should be left on one side. When processing the mold frame inserts at the bottom with rough machining on convex cores, ensure that there is a 10mm margin at the bottom straight position. This allows the operator to check for any looseness during the rough machining process. For special-shaped convex cores that require quenching, also leave a 10mm margin at the bottom straight position to facilitate centering of the surface during fine machining after the quenching process.
2. All glue positions should be left with 0.02mm during finishing (except for special requirements), and +0.02~0mm should be left at the positions where the insertion and collision occur.
3. When finishing the convex CORE shape, the programmer should open the compensation and leave a 0.02mm margin on one side when making the light knife program. The operator should measure the tolerance on one side according to the drawing size and 0~–0.005mm for easy assembly.
4. For information regarding the centering issue of mold inserts (convex CORE) with irregular shapes, please refer to the following section.
4. Slides and inserts
1. When receiving the workpiece, the programmer should measure its dimensions to prevent issues related to centering and unilateral collisions. It is important for the programmer to consult with the operations team about the shape of the workpiece and to select a safe clamping and collision method accordingly. For more information, please refer to the following section.
2. The slide and the front and rear mold cores have matching positions. The slide needs to leave an extra 0.02mm margin for FIT.
3. All glue positions should leave 0.02mm on one side (except for special requirements).
5. Slanted top
Discuss with the operation team based on the shape of the workpiece, adopt a safe clamping method, the number of touches method, and leave 0.02mm on one side of all glue positions (except for special requirements).
6. Mold base processing
1. Mold base
- The chamfer on the mold base drawing must match the reference on the mold base. To prevent misunderstanding during processing, ensure the reference edge is oriented towards you when programming.
- The processing position of all templates establishes coordinates with the center of the guide post hole near the reference angle as the origin.
- Definition of Z Value Collision Number: All templates are processed in both forward and reverse directions. The collision number at the bottom of the mold base serves as the reference zero position. For workpieces with special requirements, the programmer must clearly communicate these requirements to the relevant personnel and explicitly indicate the mold’s zero position based on the program sheet.
2. Plate A
- Finishing the mold frame is an important step in the process. When the program processes the bottom of the mold frame, the size must be determined according to the specified dimensions in the drawing. The CNC operator uses a calibration table to measure the dimensions, ensuring they are within the drawing’s tolerances. The tolerance level is denoted as +0.01~+0.02mm.
For the edge finishing of the frame, the program requires a single-sided compensation of 0.02 mm. The operator utilizes a block gauge to ensure that the size matches the drawing specifications. It is essential that the tolerance is maintained within a range of 0.02 mm to 0.01 mm on a single side.
- The edge locking position is determined based on the drawing size. The side block gauge should fit tightly. The tolerance is guaranteed to be within +0.015~-0.01mm on one side.
- The depth of the insert groove depends on its size, and the side must be tested using a block gauge. The tolerance is guaranteed to be within +0.015~+0.01mm on one side.
3. B plate
(1) The finishing of the mold frame involves the precise processing of the frame’s bottom to ensure it meets the required dimensions. The CNC operator will utilize a calibration table to measure the dimensions according to the specified drawing tolerances. The tolerance is +0.01mm.
For the finishing of the frame edges, the program must implement a compensation on one side to maintain a margin of 0.02 mm. The operator should use a block gauge to ensure that the size aligns with the drawing specifications. The tolerance for this process is guaranteed to be within 0.02 mm to 0.01 mm on one side.
(2) The depth (Z value) of the mold frame row slot bottom must be processed according to the specified drawing size. The operator will use a calibration table to measure the depth in accordance with the drawing’s tolerance, which is noted as +0.01~+0.02mm. Additionally, the side program needs to implement a single-side compensation, allowing for a 0.02 mm margin for trial matching. The operator should utilize a block gauge to ensure the tolerance is met. The tolerance on a single side should be guaranteed to remain within +0.015~+0.01mm.
4. Ejector panel
- When machining the depth of the ejector countersunk head, it should be set to 0.02 mm. The operator will use a micrometer to measure this depth, and the acceptable tolerance is between 0.01 mm and 0.02 mm. Additionally, the sides of the ejector countersunk head need to be machined to the specified size.
- During the auto machining of the inclined ejector base, the bottom of the ejector panel is used as the reference point for determining the assembly size. The operator employs a comparator to measure the dimensions accurately, ensuring that the side machining sizes are correctly achieved.
- Other positions are machined to the standard size according to the size of the 3D drawing.
5. Ejector base plate
- For the size position with assembly requirements for the insert, the operator must use a block gauge to ensure a tight fit. The other positions should be processed according to the dimensions specified in the 3D drawing to achieve accurate sizing.
- C Plate: Process the dimensions accurately according to the 3D drawing. Select the processing surface and direction based on the positive direction indicated by the A code of the gong machine assembly.
- Nameplate: The characters must be engraved according to the specifications outlined in the 3D drawing.
-Upper Fixed Plate: The size of the nozzle position has specific assembly requirements. The bottom of the upper fixed plate must be processed to the exact size. The operator should use a calibration table to measure the dimensions, and side processing must include compensation. The program should leave a tolerance of 0.02 mm on one side. The operator needs to use a needle gauge to ensure a tight fit on a single side, maintaining the measurement within +0.015~+0.01mm; other dimensions should be processed according to the 3D drawing.
-Lower Fixed Plate: For the insert assembly requirements, the bottom of the lower fixed plate needs to be processed to the exact size. The sides should fit tightly using a block gauge, and other dimensions should be processed according to the 3D drawing.
7. Programming
- Definition of Steel Material Processing Coordinates:
The rectangular datum faces the operator, while the square datum aligns with the lower right corner. Typically, all steel material programming uses the X and Y center as the origin (0, 0) and sets the Z value as 0 to establish processing coordinates. (Refer to the CNC processing coordinate definitions and clamping direction standard figures 1, 2, and 3 for clarification.)
- Leave 0.5mm on one side of the rough processing program, and leave a process table on the top of the mold core to facilitate clamping during fine processing.
- Finish the first gongs at the bottom of the mold core to avoid hitting the front of the mold core, PL, glue position, etc.
- Mold core tube position: All front and rear mold core tube position programming is 0.01mm smaller on one side.
- Plane PL processing:
The program processing must be accurate to the size of the drawing, and the operator must use a calibration table to ensure that the measurement tolerance is within +0.01~0mm.
- For arc surface PL processing, the programmer creates a test knife program. The program sheet outlines the connection to the bottom plane (PL). The light knife processing program is precise regarding dimensions. When defining the machining coordinates for the front and rear mold cores, the rectangular reference should face the front, while the square reference should be oriented towards the lower right corner. (the center of the four sides of X and Y is 0, and the bottom of Z is 0), as shown in Figures 1, 2, and 3:
The convex CORE hit counts are shown in Figures 4 and 5:
The number of row seat collisions is shown in Figure 6:
The mold base collision number is shown in Figure 7:
If you want to know more or inquiry, please feel free to contact info@anebon.com
Anebon has numerous great personnel members who are good at advertising, QC, and working with troublesome dilemmas from the creation course of action for China Supplier. LST-106MY High Cost-Effectiveness CNC machining parts, milling aluminum parts and CNC turned components with high-speed machining.