Computer numerical control or CNC is a type of machine that uses computer technology to create parts. CNC machining is a modern approach to handmade machine parts. The design of the parts done by computer. Entering specific information into the computer software provides the information necessary to manufacture parts, and the computer controls the automation of the manufacture of parts to specific dimensions. This allows accurate identification of parts.
Even complicated parts or small parts are making to the same specifications every time. This type of machining allows for more consistent parts and faster exit times. The computer can also dictate the best way to produce the parts, leaving as little waste as possible. A business of any size can save time and money by using this type of machining.
We all know that dynamic machining technology uses to improve the efficiency of CNC machining in CNC roughing. So in CNC finishing, which is more time-consuming, is there any way to improve machining efficiency?
The purpose of CNC finishing is to ensure the final dimensional accuracy and surface quality of the workpiece. To improve the finishing efficiency, it is necessary to consider the two aspects of surface quality and finishing time.
Let’s first analyze the surface quality during finishing, which largely depends on the height of the residual ridge left after machining.
1. what is the height of the residual ridge?
The height of the residual ridge refers to the maximum height of the convex part of the residual material after the tool has passed through two adjacent tool paths during machining.
2. how to reduce the height of the rest ridge?
One possible method is to reduce the step size and decrease the distance between adjacent tool paths. However, this means increasing the number and density of tool paths per unit area and increasing the finishing time. Therefore, in CNC finishing of 3D surfaces, everyone will feel that there is a dilemma between “surface quality” and “machining time.”
Better surface quality = longer machining time.
Another viable method is to use a larger tool. This is because the larger the tool radius, the larger the arc at the contact point when it comes into contact with the material. For the same tool path density, the land height achieved is smaller.
3. use a tool with a large radius or a tool with a small radius?
Using a large radius tool can reduce the height of the residual ridge and achieve better surface quality. But a new problem arises: Many workpieces finish with narrow gaps. And these cannot finish with large radius tools.
Large radius tool CNC finishing:
Lower residual ridge height; Shorter cycle time.
No small gap area can be machined; Easy to interfere with, complicated to program.
Small radius tool CNC finishing:
Easy to program
To achieve better surface quality, you need to reduce the step distance and increase the tool path density; Longer machining time.
4. is there a better way
Is there a way to integrate the advantages of the two and avoid their disadvantages?
The answer is yes.
A careful analysis of the process of creating the residual ridge height shows that the residual ridge height is actually related to the arc radius of the contact point between the tool and the material, and has little to do with the tool radius itself. If you only increase the arc radius of the effective machining portion of the tool, while leaving the size of the radius of the tool body unchanged, you may be able to achieve the dual goals of improving surface quality and reducing finishing time simultaneously.
In fact, some tool manufacturers have begun research in this area and have introduced a variety of large arc radius tools suitable for different machining scenarios.
5. can we start machining with the tool?
As mentioned above, by changing the shape of the tool, increasing the arc radius of the contact point between the tool and the material during machining, and reducing the height of the residual ridge left by the CNC finishing process, the number and density of toolpaths required in the finishing area can be greatly reduced. Machining time is greatly reduced and production efficiency is improved.
But again, there is a new problem: the shape of the effective machining radius in this type of large arc cutter is complex, and the tool path must be compensated based on the complex shape of the tool so that the large arc of the tool fits accurately into the machining position and the finishing surface quality requirements are met. How should such a toolpath be programmed?
This requires CAM software to assist with programming. Mastercam’s Accelerated Finishing TM superstring finishing technology is a programming solution for efficient finishing with circular arc tools. It can dynamically compensate for tool contact points in the machining process, based on the shape of the tool and through special tool path algorithms for large circular arc tools of various shapes, and can take full advantage of the shape of the circular arc tool to perform high-precision and high-efficiency finishing.