How to control the CNC machine?
CNC milling operation method
Our CNC milling part design guidelines are not too complicated, and if you follow these guidelines, your parts will easily pass inspection. CNC milling is special in that it uses a rotating tool whose sharp edge is able to remove material from the workpiece.
Due to the wide variety of cutting tools available, milling machines can be used for many operations. For example: fly mills, end mills and end mills, they all play different roles, allowing the mechanic to practice a variety of cuts on the workpiece.
about CNC milling design
When we designparts for CNC milling, there are a lot of important factors that decide what is an presentable design and what isn't. These contain the machine setup or workpiece direction, the shape and the length of the cutting tool, and the material of workpiece.
orientation of Workpiece
An important factor for CNC milling design is the setup of machine or the manner in which the workpiece is clamped onto the workbench. since the workpiece has to be fixed onto the worktable, its one side is unable to approach to thelathe, that means machinists must think about which way the workpiece should be oriented.
only parts with features on one side are easy to mill,the reason is that the featureless side can face downwards, making the machine tool reach the featured side. parts with details on all sides need repeated setups: when one side is being milled, the workpiece should be removed from the workholding apparatuses, turned over,and then milled on the other side.
Designers must design parts so that they can be milled with the fewest setups, because every new setup requires time and calibration, it will increase the cost of parts.
Key components of CNC machine tools
chief axis: spins the cutting tool at high speeds.
Cutting Tools: End mills, face mills, drills, etc, based on material and design selection.•
workbench: Fixes the workpiece in place using vises or clamps.
Control Panel: Interface for inputting commands and monitoring operations.
Geometric shape and diameter of cutting tools
Another specialpoint of CNC milling that affects part design is the geometricshape and diameter of the cutting tool. There are two key factors to consider here. first of all, because the cutting tool is continuously rotating, it generates a circular cutThis makes it impossible to perform right angle milling on internal angles.. Why? its own geometry is a mismatch with the surroundings.
The diameter of cutting tools also limits the design of parts .cutting tools cannot cut a cavity that is smaller than itself, Therefore, although larger tools are very suitable for removing large pieces of material, they cannot produce fine details.
Tool length
The ultimate key design constraint for CNC milling is tool depth, which refers to how far the cutting tool can penetrate the workpiece.On paper, as long as the tool is long enough, any hole depth can be milled..However, the longer the tool, the greater the possibility of chatter: unwanted vibrations can reduce the accuracy of milling operations.
Workpiece material
Different metals and plastics have varying degrees of processability that is,The difficulty of cutting them by a CNC milling machine without deformation (or damage to the tool).
In the process of CNC milling design, the machinability of materials should be considered, especially when strict tolerances and fine details are required. for instance, compared to parts made of harder metals such as stainless steel 440, parts made of aluminum 6061 may be able to accommodate deeper holes and achieve stricter dimensional tolerances.
How to deal with some limiting factors of CNC milling parts?
We have studied how to deal with some limiting factors of CNC milling parts.. Now let's take a look at some CNC milling design principles and rules based on these factors.
Part size
An obvious consideration in CNC milling part design is the maximum part size, which depends on the working range of the CNC milling machine used. For reference, Dahong's precision three-axis milling machine has a maximum operating range of 850x 500 x 500 mm.
Align features
Because setting up workpieces multiple times requires time and money, designers should try aligning features such as holes and vertical walls on one surface.This makes mechanics mill all features of a part with just one setup..
However, using a 5-axis machining center can provide flexibility for off-axis features and holes,because cutting tools can approach the workpiece from more angles without the need for new settings.
Radii
Operators need to keep in mind that the round shape of the cutting tool makes it impossible to mill square interior corners without using complex bottom cuts. Instead, the inside Angle will be rounded and the radius will be determined by the diameter of the tool. In other words, using an inside angular radius that is slightly larger than the tool radius will yield better results because it provides clearance for the tool to turn. In addition, specifying the same radius for each inside corner means milling can be done faster.
Cavity depth
To minimize chatter, tool deviation, and other issues as much as possible, Milling parts could only have cavities of limited depth. According to experience, the depth ofcavity should not exceed four times its width.
Wall thickness
When CNC milling thin walls, such as for reinforcing ribs in parts, designers should not specify a metal thickness less than 0.8 millimeters and a plastic thickness of approximately twice that.
In addition, the height of these thin walls should ideally not exceed 10 times the wall thickness, that is, the height of a wall with a thickness of 5mm should not exceed 50mm.
Holes and threads
Designersought to specify holes and threads with diameters that correspond to standard drill bits and threading tools as much as possible..Non standard diameters are possible, but end mills must be used for cutting.
Depth and width of the hole must be considered. in most instances,The depth of the hole should not exceed about 10 times the diameter, although special drill bits can be used to drill deeper holes
The bottom of blind holes (holes that do not fully penetrate the workpiece) will only flatten when cut with an end mill.. provided cut with a drill bit, it would have a conical base.
Lettering
When adding text to the surface of a CNC milled part, engraving is more effective than embossing because less material is removed. Also, round sans-serif fonts are easier to grind than decorative fonts.
Tolerances
when designing parts for CNC milling ,Designers must consider realistic tolerances. The standard tolerance is 0.1 millimeters; More stringent values (as low as about 0.01mm) can be achieved, but additional time and cost are required.
Best Practices for CNC Millingoptimization
Machine Setup
Fix the Workpiece: Use fixtures, pliers, or jigs to prevent movement during the machining process
Tool Selection: Choose appropriate cutting tools (e.g. hard alloy end mills for metals, high-speed steel for plastics)
Calibration: Set the workpiece zero point (G54 offset) and tool length offset.
Machining Operations
Surface Treatment: Create a smooth surface on the workpiece
Groove: Remove material to form cavities.
lineament: Shape the outer edge of the component.
Drilling: Add holes withaccurate depths and diameters.
quality assurance
Use calipers, micrometers, or coordinate measuring machines (CMM) to verify dimensions and the degree of finish of surface.
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At Dahong Precision - we are your partner in the field of Non-standard mechanical parts. Precision, material adaptability, cost efficiency is our aim.
Contact us today to discuss your project and find out how we can help you achieve your goals.
