Week 9 - Attachment Feature Creation - Challenge 1

 ANSWER:

AIM: Create the rib for the Centre console coin holder considering the design rules mentioned

Objective: The creation of rib can be done to the solid model of any component. The ribs are designed on B side surface. That's why ribs are known as B-side features.

Usage of ribs:
Ribs provide a means to economical stiffness and strength in molded parts without increasing overall wall thickness.

They facilitate:
1. Locating and arresting components of an assembly.
2. Providing alignment in mating parts.
3. Acting stops or guides for mechanisms.

Issues that cause while designing proper rib:
Thickness
Height
Location
Quantity
Manufacturability

points to be remember

• due to more thickness of the rib, the sinks are formed

• If the distance between two ribs are less, sink marks are formed

 

• Maximum Rib height can be five times as component thickness

 

Design rules for designing a rib on any component:

 

Steps involved in Rib creation:

• Thickness(t) = 2.5mm
• Rib draft - 0.5 degrees
• Rib filler radius (r) = 0.25 mm
• Rib root thickness should be > 30% of thickness
• Rib thickness(w) = 0.4*2.5 = 1 mm
• Rib depth = 5*2.5 = 12.5 mm (considering minimum value)
• Spacing distance between two ribs can be calculated using the relation Rib depth/Rib thickness ≤ 3
• Equating the Rib depth (w=12.5mm) and considering the ratio value = 3mm and we get  W = 12.5/3 = 4.166 mm
  
  A sketch on the bottom face of the coin holder is drawn for rib creation. Extruding in the direction of the tooling axis

Creation of tooling axis:
Since the model is a coin holder, which is like a bin, we can always take the tooling axis direction w.r.t the bottom surface as shown in the figure.
First, we need to check in all directions for the tooling axis for the core and cavity direction.
The draft angle needs to check for all surfaces so that no interference occurs while ejecting the core and cavity.
First, extract the bottom surface and create a point. With help of a point creates a line in the perpendicular direction of the surface.

Creating a rib by extruding the surface and giving values accordingly. After taking intersection with the body, we get rib root thickness as 2.68 mm as diameter, which can be considerable

The distance between two ribs should be greater than 4.16 mm according to the calculation

iso-metric views:

tree structure:

DRAFT ANALYSIS:

ribs are in a negative direction so it is a blue color

Conclusion:
In this way, ribs are created on bodies with design considerations