CAM-TOOL is a CAD/CAM integrated multifunctional system for mold with the concept of ‘As it is, just as it is. Flexible Mold/Die Manufacturing’.
In this article, we would like to introduce an example of improving work efficiency at the mold manufacturing site by using "surface calculation", which is the unique calculation logic of CAM-TOOL.
CAM-TOOL is equipped with two types of calculation logic: the commonly used "polygon calculation method" and the originally developed "surface calculation method" specialized for ‘high quality’, ‘high precision’, and ‘high hardness’ machining
CAM-TOOL's "Surface calculation" achieves optimal milling and high-precision by using a unique algorithm that brings the tool into contact with the curved surface shape without converting the received data (IGES, etc.) into approximate polygons.
The machining sample below is a surface quality comparison sample that shows the difference.
The one on the left, toolpaths were created using surface calculation to achieve a shape tolerance of 0.5μ, and for the one on the right, toolpaths were created in separate areas to achieve polygon tolerances of 0.5μ, 1μ, 10μ, and 30μ, and machining was performed under the same conditions for the tool, machining conditions, and cutting direction.
Improving the surface quality not only reduces the polishing work time, but also improves the tool life by eliminating the intermittent load on the tool in the next process by making the finishing allowance uniform in the intermediate finishing stage.
This is a sample of electrode machining for THAI METALEX 2020 done with Sodick TS50L.
The pin diameter is 0.5 mm, the height is 10 mm, and the vertical wall is 0°, which is considered very difficult to machine. The pins converted to polygons are represented by triangles and machined with undercut shapes, resulting in bent or broken pins.
The same can be said for the deep rib shape, which is close to the vertical wall in mold machining, causing the following problems.
・ Cracks and breaks in long neck tools
・ Dimensional defects
・ Poor surface quality (= shape is finished in undercut) → Poor mold release of molded products
In "surface calculation", it is possible to create high-precision toolpaths with the shape as it is, and various problems can be solved.
We have created a new sample to see how the difference in surface quality affects the polishing work.
The material is a common for Injection mold STAVAX (52HRC).
The workpiece is divided into 4 areas. Surface A to D (hereinafter A to D), with 2 groups, and the processing time and the number of compounds to achieve a hand-finished mirror surface were compared.
C and B started with #600 and finished with #6000 for a mirror finish.
A was started with #3000, but there was no change after 30 minutes, so changed to #1200. It took a total of 300 minutes to get a mirror surface. D was machined by "Surface calculation" and it was very easy to get a mirror surface with # 3000 and # 6000 process. Total is only 152 minutes.
As an impression, even though it is 1μ tolerance, there were fine polygon patterns on the entire surface, and #3000 was not enough to level out, and number had to be dropped by 2 classes to do rough polishing. But the one machined by "surface calculation" had no polygons at all, and the leveling work was minimal, thus starting with #3000 was sufficient. This also has the advantage of creating a mirror surface without destroying the shape.
As described above, we were able to prove a significant reduction in the post-processing steps, which tends to depend on know-how, simply by improving the data accuracy of CAM.