C-axis MillTurn Feature Recogintion

MillTurn centers are on the increase, which are turning centers with live milling tool on the tool post with C-axis spindle control. Manufacturing view feature recognition library has added a new functionality to recognize such C-axis features in MillTurn module, apart from recognizing turning and milling features. FR further classifies the feature into C-axis-pockets and C-axis-slots as shown in Fig 1. 

Fig 1. C-axis Pockets and Slots

Bevel Recognition and Unfolding

Bevel cutting in thick plates can be cut in laser/plasma/waterjet/milling machines with tilt head. FR has developed bevel feature recognition in which four types of bevels such as V-Bevel, Y-Bevel, X-Bevel and K-Bevel can be recognized.  

 

Fig 1. Different Types of Bevels

Bevels are not only recognized on just planar surfaces, but can also be recognized on bent surfaces as shown in Fig 2.

Fig 2. Bevels on Bends

Unfold can also be generated as shown in Fig 3 for components with bevel features. 

Fig 3. Bevel Unfolding

Recognition of Hole types and Compound Cutouts

Sheet metal parts generally contain holes and cutouts. Holes can be simple holes, tapered holes, counter-bore holes, counter-drill holes and counter-sunk holes, as shown in Fig 1 from left to right respectively.

Fig 1. Different Hole Types

Similarly, cutouts can also have such cross sections, which are termed as compound cutouts. Sheet metal feature recognition library can recognize all these compound cutouts and can also classify cutout shapes such as obround, rectangular with/without corner fillets and generic shapes.  

Fig 2. Different Compound Cutouts

All these types of holes and cutouts are recognized by sheet metal feature recognition library as shown in Fig 3. Recognition of such features and associated parameters are very useful in automatic tool selection. For downloading evaluation version click here. 

Fig 3. Feature Recognition of Hole Types and Compound Cutouts

Marking and Half-shear Recognition

FR has recently added capability to recognize marking and half-shear features in sheet metal feature recognition library. Markings are generally inscribed on sheet metal parts, which are depressions that do not penetrate the sheet completely but partially as highlighted in green in Fig 1.

Fig 1. Marking features

Marking features with different cross sections as shown in Fig 2 can be handled efficiently. 

Fig 2. Cross section of various marking features

Half-shears are features that can be of any shape that are sheared partially in a sheet. The cross section of a circular half-shear is shown in Fig 3. Geometrically half-shears create a pocket on one side and island on the other side of the sheet. 

Fig 3. Cross-section of a half-shear

Few half-shears that can be recognized by sheet metal feature recognition library are shown below in Fig 4.

Fig 4a. Pocket side of half-shears

Fig 4b. Island side of half-shears

FR can recognize Fasteners

FR sheet metal library can recognize a variety of fasteners in sheet metal models such as

1. Square weld nuts
2. Hexagonal weld nuts
3. T weld nuts
4. Spacers
5. Stud fasteners

Unfolding Shell Models

For designing design sheet metal models, some designers use solid modeling commands rather than sheet metal commands. Such models are made initially using solid modeling commands and then shell command is used to get uniform wall thickness and finally the model is converted into a sheet metal model. Such models when received by manufacturing vendors are often not suitable for unfolding. There are two reasons for this (i) unripped edges and (ii) sharp bends. To handle such cases, Sheet Metal Feature Recognition library (SMFR) provides options like (i) ripping and (ii) insert bends.

Model with an Unripped Edge and Sharp bends

For example consider the model shown in the figure above. Faces A and B are connected together, whereas to unfold the model, both these faces need to be unconnected. The unripped edge shown in the figure needs to be ripped. Sheet Metal Feature Recognition library provides an option to rip such edges in imported solid models. The edges to be ripped and the rip gap are to be provided for ripping. The imported model after ripping is shown below.

Model after Ripping

The model has two sharp bends with inner radius and outer radius as zero. For accurate unfolding and sheet metal bending, inner radius has to be specified. Sheet Metal Feature Recognition library provides an option to automatically convert such sharp bends into cylindrical bends. The sharp bend and the inner radius are to be specified for automatic conversion. SMFR can also detect sharp bends automatically for such conversion. The imported model after conversion of sharp bends into cylindrical bends and flat pattern obtained using SMFR are shown below.

Model after Conversion of Sharp Bends into Cylindrical BendsFlat Pattern

Unfolding imported models with flanges

Unfolding imported sheet metal models in CAD modelers always has limitations. Imported models having flanges as that shown in the figure below are not possible to unfold in most of the CAD modelers.

The latest version of Sheet Metal FR now has the capability to unfold imported models with such flanges. By enabling the patch stamps option, the above imported model can be unfolded with ease as shown below.

Click here for an evaluation