How to Skillfully Utilize 3D CAD to Carry a Variety of Ideas for Machining Functions

2023-12-13 11:50:12

Modeling differences between machined parts and resin molded parts

In 3D CAD modeling, parts can be made in a variety of ways, and changing the modeling method depending on whether the part is made by machining or resin molding minimizes the risk of design rework or making it difficult for the manufacturing department to work.

However, since the basis of the design is to design the shape of the part that meets the required specifications, the priority of processing should be second.

The modeling of mechanical parts is basically carried out in the cutting direction

First of all, it will start from the modeling of the shape part, and take into account the machining allowance and make it slightly larger. Then use the cutting function to cut the model while completing the shape of the part. If the material machining process is properly modeled, the design can be carried out while taking into account the machinability.

In machined parts, when performing additive modeling such as bosses, the volume removed by processing will increase, and the material cost and processing cost will increase.

The modeling of resin molded parts is basically carried out in the adding direction and the cutting direction

Compared with machined parts, resin molded parts can achieve more functions by making the shape of the parts more complex. Therefore, modeling in 3D CAD can also use a combination of stretching and cutting functions. In addition, it is also possible to utilize functions dedicated to resin molding, such as a shell command and a mold lifting inclination.

Modeling with machining in mind

1. The initial characteristic shape should be made of standard length materials as much as possible, or standard plates should be used. By designating a region in which design is allowed, it is possible to design at a cost and reduce wasteful use of large materials.

2. The cutting shape should use a quadrilateral parallel to the XY direction. By preventing oblique cutting and curve cutting, machining efficiency can be improved. And no need to use CNC machine tools.

3. The depth of the groove shape should be as shallow as possible, and the internal corners should be chamfered, and the chamfering radius should match the specified diameter of the end mill. Since the groove shape is machined by an end mill with a milling machine, if the depth is reduced, the machining time can be shortened. If the inner corner of the groove is a sharp corner, machining cannot be performed using an end mill, and the cost using electrical discharge machining or the like increases. By using the machining verification function of 3D CAD, it is also possible to check the shape of the groove that is not suitable for machining.

4. The cut shape is made downward in the Z direction. In actual machining, cutting is also performed by moving the tool up and down in the Z direction. By performing production using such a modeling method, it is possible to automatically ensure workability. In addition, it is possible to reduce the man-hour for remounting the rotary working material on the jig.

5. The hole shape uses a dedicated drilling function. 3D CAD has a function dedicated to holes, using standard values to manage the diameter like a drill. In addition, only the nominal diameter of the screw needs to be specified, and the hole can be drilled with the appropriate pre-drilled hole diameter. As a result, modeling errors caused by the wrong special drill diameter holes not available in the factory can be avoided.

3D CAD features suitable for machining

Since 3D CAD was developed as a design tool, the modeling was able to reproduce the actual machining. Since commands corresponding to the surface processing, the hole processing, the chamfering processing, and the like are provided, it is possible to implement the design in consideration of the machining described above.