Week 8 - Challenge 4 - Bumper

Week 8 - Challenge 4 – Bumper

OBJECTIVES:

• To create the class B and class C surfaces from the given class A surface
• To form a solid geometry by combining all the surfaces
• To perform draft analysis on the class A surface and the solid part model

PRE-DESIGN CHECKS:

Before starting the creation of the class B surface we must ensure that the given class A surface is properly closed and the surface continuity is proper. This can be done either with the help of the join operation or by using the boundary feature.

TOOLING AXIS:

• The next step is to create the tooling axis for the part which will determine the direction in which the core and cavity of the mould will move.
• Designer must ensure that all holes and slots are covered in the main tooling and thus side core must be avoided whenever possible
• After analysing visually for the best possible tooling axis, an axis system is created on the centre of one of the surfaces of the bumper.
• First a dummy tooling axis is drawn along the X direction with the axis system and the centre point as reference
• Next the main tooling axis is drawn in the YZ plane using the bisecting line method

DRAFT ANALYSIS:

• Draft analysis is done on the class a surface after the tooling axis has been obtained
• The part must have a minimum draft angle of 3 degrees on all the tapered faces
• Using the feature draft analysis tool and the compass the part surface is validated for the minimum draft criteria

CLASS B SURFACE                                                                                                                           

• After all the validation has been done, the class B surface is created by offsetting the class B surface to a distance of 3mm
• After offsetting many openings in the surfaces are found which are closed with the help of sweep, multi sections-surface and fill command.
• The class B surface is then extrapolated in parts to trim it along with the class C surface

 

CLASS C SURFACE

• The class C surface which connects the class A and class B surface is created by sweeping the boundary of the class A and using the class A as a reference.
• The sweep is divided into several parts in order to avoid complexity
• Surfaces which are parallel to the tooling direction are swept with the tooling axis as reference and with a draft angle of 3degrees

PART:

The final trim is created by joining the Class A and C surface and finally trimming it with the Class B surface. The combination of class A, B and C surface is then converted into a solid with the aid of fill command in the part workbench

    

  

DRAFT ANALYSIS ON PART:

• Draft analysis is done on the final part with the tooling axis as reference
• Green surface indicates the areas where the draft is more than 3 degrees.
• Red surface indicates the area having negative draft.