Base Bracket Design

DRAFT ANALYSIS ON BASE BRACKET

Objective:

The main aim of this report is to explain how the tooling axis was created for the given class A surface of a base bracket and the steps involved in draft analysis with respect to the created tooling axis. And the creation of class B & C surface from the class A, to create solid part out of those surfaces.

Description:

Class A surface:

The class A surface of a base bracket is given to do the draft analysis.

Isometric view of the given class A surface of base bracket.

Test-1:

In this test the surface continuity of the given class A surface is examined to avoid gaps. If any gaps or discontinuity is present in the class A surface, we cannot thicken or use closed surface command to create a solid part out of it.

Joining:

By applying joining command to the class A surface, we can test the continuity of the class A surface of the given base bracket by examining its edges.

Boundary:

By applying boundary command to the class A surface of the base bracket, we can create a boundary line of the open edges. With help of this boundary line the continuity is tested visually.

Boundary of class A surface shown in the above picture.

If any gaps or discontinuity in the class A surface is found we have to correct it for further process.

We can use either joining or boundary for this test.

Test-2:

In this test, the tooling axis is created along the x, y and z directions, to choose the best tooling axis out of it. To reduce the tooling cost.

Dummy axis:

Dummy axis is a line created at the centre of the given class A surface for our reference.

Class A surface with dummy tooling axis is shown in the above picture.

Intersect:

The class A surface is intersected along the yz plane to create intersecting lines. This intersecting line is used to create lines which are considered as difficult or complex to manufacture according to the tooling axis.

Intersected along yz plane.

Tooling axis:

Tooling axis is used to define the direction of core and cavity movement of a moulding machine according to the component to be moulded.

Isometric view of class A surface.

Class A surface along X axis, in this direction the large hole on top of the class A can only achieved with help of the side core this can increase the cost and the small hole cannot be achieved in this direction.

Class A surface along Y axis, in this direction also the large hole on top of the class A can only achieved with help of the side core this can increase the cost and the small hole cannot be achieved in this direction.

Class A surface along Z axis, in this direction the holes on top of the class A can easily achieved with core and cavity itself.

In this case, the tooling axis is created along the z direction. Because it is the only possibility where there is no need of extra side core. Also, it is cost efficient considered with other tooling axis.

• By using the bisecting line command, a bisecting line is created with reference to those lines created previously and to the point. This bisecting line is considered as tooling axis.

Bisecting line with reference to the point and lines created is shown.

Final tooling axis is shown.

• This tooling axis decides the movement direction of core and cavity to manufacture the base bracket.

Draft analysis:

The draft analysis command enables you to detect if the part you drafted will be easily removed. This type of analysis is performed based on color ranges identifying zones on the analysed element where the deviation from the draft direction at any point, corresponds to specified values.

Draft analysis is carried out to check the drafts in the class A surface of base bracket is feasible. The nominal draft for plastic components is 3º and 0.5º is the minimum draft value.

• After the creation of tooling axis, the feature draft analysis command is applied to do the analysis.
• By using the direction tool, the compass to define the new current draft direction is placed along the tooling axis. Then the draft direction is locked.
• In the display tool, the color scale is opened to give the limits for the draft analysis and then the surface is selected to test the draft for the given limits. If the color of the surface is changed to green, then the draft of the component is able to be manufactured.
• If the color of the surface is changed to red, then the class A surface is failed in draft analysis test and it is difficult to manufacture the component in cost effective manner.
• In this case, the class A surface of base bracket is passed in the draft analysis and the part body of it can be created for further process.

Draft analysis of the class A surface with nominal draft is shown in the picture.

Draft analysis of the class A of Base Bracket is shown.

The same procedure is followed to conduct draft analysis on the solid part also,

Draft analysis of the part with nominal draft is shown.

Draft analysis of base bracket is shown.

B Surface:

B surface are said to be the engineering surface which has all the ribs and fixing elements in it. This B surface is created with reference to the given class A surface.

• After completing the draft analysis, if the class A surface is passed then the class B surface creation starts.
• Extract the necessary surface from the class A and untrim those surfaces to extrapolate it.
• After the extrapolation, trim command is applied to remove the unwanted surfaces.
• Then this surface is offset to the required thickness value and then the fillets were applied.
• This offset surface is said to be class B surface.

B surface shown in the above picture.

C Surface:

C surface are said to be the connecting surface of class A surface with the B surface.

• Boundary command is applied to the open edges of the class A surface to create a boundary line.
• This boundary line is used to create the sweep along the draft direction with enough value to overlap the B surface.
• It is said to be class C surface.

C surface shown in the above picture.

Closed surface:

Closed surface is the final surface used to create the solid part by applying the closed surface command in the part workbench.

• After the creation of class A,B & C surfaces they are joined and trimmed to form the closed surface.

Closed surface is shown.

Sectioned view of closed surface.

Solid part:

Solid part is created by applying the closed surface command in the part workbench to the closed surface which is created with the help of class A, B & C surface.

Isometric view of solid part.

Conclusion:

The creation of tooling axis and the steps involved in draft analysis of base bracket is explained in detail with respect to the reference images regarding to the given class A surface of base bracket. And, the steps involved in class B & C surface and solid part creations are also explained in detail with reference images.