This function unfolds flanges on a part so the user can create an addendum with an unfolded part trim line.

Figure 6.1.9  Unfold flange

There are two methods to unfold flange, as illustrated in Figure 6.1.9.

l   Geometric Unfold

This function unfolds the selected flange surface to the plane where base surface locates. Once the function is selected, eta/DYNAFORM opens the Select Surface dialog box to select flange surfaces to be unfolded. Refer to Figure 6.1.10 for typical surfaces with the defined flange highlighted.

Figure 6.1.10  Select flange surface

After selecting surfaces, the program will automatically determine and highlight the unfold line and the boundary line. As shown in Figure 6.1.11, the bold line is the unfold line, and the other is the boundary line of the base surface.  eta/DYNAFORM displays a Select Option dialog box as illustrated in Figure 6.1.12. The user has to select an option to continue operation.

Figure 6.1.11  Unfold line and boundary line

Figure 6.1.12  Select option

If the unfold line and boundary line are correct, select Accept to continue. The program will unfold the selected surfaces along the unfold line and continue to the next step.

If the unfold line is not correct, select Retry.  eta/DYNAFORM will use a different method to find the desired unfold line and boundary line.

If Adjust Gap Tolerance is selected, the dialog box illustrated in Figure 6.1.13 is displayed to allow the user to change the gap tolerance between surfaces.

Figure 6.1.13  Gap tolerance

The default gap tolerance is 2.5mm. If there are small surfaces in the part, a smaller gap tolerance should be used. If Select Base Surfaces is selected, eta/DYNAFORM allows the user to select a surface as the base surface. A base surface is a surface that connects the flange surfaces along the unfold line.

The Input Bent Angle dialog box as illustrated in Figure 6.1.14 is displayed.  The bent angle is the angle between the unfolded surface and the base surface.  The default angle (0 deg) indicates that unfolded surfaces are tangent to the base surfaces at the unfold line.

Figure 6.1.14  Input bent angle dialog box

Select OK to accept the defined bent angle. The unfolded surfaces are shown in Figure 6.1.15 in yellow.

Figure 6.1.15  Unfolded flange

The unfolded surfaces are automatically stored in a new part named UNFOLDED.

Select an option from the Control Keys dialog box as illustrated in Figure 6.1.16.

Figure 6.1.16  Control keys dialog box

Smooth Edge

This function allows the user to smooth the edge of unfolded surfaces. eta/DYNAFORM will prompt the user to select the starting and ending points on the edge of the unfolded flange. The smoothed edge will be highlighted as shown inFigure 6.1.17. The Control Keys dialog box as illustrated in Figure 6.1.18 is displayed. The user has to select the next step from the options provided in the dialog box.

Figure 6.1.17  Smooth edge

Figure 6.1.18  Control keys dialog box

Finish Smooth – Complete the smooth edge operation.

Smooth Again – Perform the smooth edge operation again.

Undo – Undo the last smooth operation.

Delete Original Flange

The original flange surfaces will be removed from the database.

Unfold Another Flange

Continue to unfold another flange by repeating the steps previously mentioned.

l    Box Unfold

This function will unfold the selected radius surface to the plane where the base surface connected with one side of the radius surface locates. The feature of the surface, which connected with the other side of the radius surface, remain unchanged. The dialog box is illustrated in Figure 6.1.19.

Figure 6.1.19  Box Unfold

Gap Tol.

This indicates the maximum gap allowed between the adjacent surfaces. If the gap between the adjacent surfaces is greater than the gap tolerance, these two adjacent surfaces are discontinuous.

Select Base Surface

Select a surface connected with the radius surface as the base surface. The radius surface is unfolded towards the plane where base surface locates. The base surface must be a flat plane. The program will prompt the user to reselect if one surface is selected.

Select Radius Surfaces

Select the radius surface connected with the base surface.

Delete Radius Surfaces

This button is enabled after the radius surface is unfolded, as illustrated in Figure 6.1.20. The unfolded radius surface is automatically included in the new part named UNFOLDED. The original radius surface is not deleted and is still included in the original part. Click this button to delete the original radius surface.

Figure 6.1.20  Delete radius surface

Apply

Click Apply button to unfold the radius surface and the surface connected with radius surface to the base surface.

Undo

Cancel the last operation.

Close

Close the Unfold Flange dialog box to exit this function.

The procedure of Box Unfold is as follows:

1. Select base surface, as illustrated in Figure 6.1.21.

Figure 6.1.21  Select base surface

2. Select radius surface, as illustrated in Figure 6.1.22.

Figure 6.1.22  Select radius surface

3. Click Apply to unfold, as illustrated in Figure 6.1.23. The unfolded radius surface is automatically included in the new part named UNFOLDED.

Figure 6.1.23  Unfolding result

Note: If the intersection line of radius surface and base surface is curve, the radius surface cannot be unfolded. The intersection line connecting the other side of radius surface and the surface must be a straight line, otherwise the radius surface still cannot be unfolded.