Week 9 - Attachment Feature Creation - Challenge 1

Aim :

To create the rib for the Centre console coin holder considering the design rules.

Introduction:

Plastic parts design is a very complex process and it requires the involvement of many factors like functional requirements, process constraints, material selection and assembly or structural issues. Wall thickness, Draft, and Textures, Ribs & Bosses, Holes/Depressions, etc. are some of the important elements to be considered in the design of plastic parts. Adhering to these basic design guidelines for injection molded parts can improve the moldability of the designs and the life of the mold, increase the operational life of the part and reduce manufacturing cost.

Ribs :

Ribs are a feature in plastic injection molded parts. They are thin extensions that run perpendicular to a wall or plane. They are commonly used to provide additional support and strength to a part.

Thickness and location are essential to rib design. Here are some helpful design guidelines:

• They should be designed with a thickness that is ½ the wall thickness to avoid a thick section at the wall base
• To minimize sink marks, design ribs that are approximately 60% of the joining wall thickness for minimum risk
• Best practices include spacing at a distance of at least twice the wall thickness
• Glossy materials require a thinner rib (40% of wall thickness)

Procedure:

since we have already designed the coin holder and we have to create the ribs on it so first extract the bottom surface of the coin holder

now we have to draw sketch on it.

now the sketch is drawn now we have to extrude it with respect to the tooling direction

The rib surface profile is then thickened 0.4 times the thickness of the component and the drafted with 0.5deg draft angle

the tooling axis is used as the pulling direction for the draft.The top tip of the rib must have a minimum thickness of 0.75mm and the designed rib has satisfied the criteria.

another rib is created by drawing another sketch is considering the minimum width between two ribs and all the operations are followed as in the first rib.

draft analysis:

• Green color indicates that the model passed in the draft analysis a
• Red color indicates that the model darft angle is 0 deg.
• Blue color defines the negative draft angle or less than zero draft angle.