Week 9 - Attachment Feature Creation - Challenge 1

Aim:

Design the rib for coin holder following the design rules and carry out rib root thickness analysis.

Introduction:

Rib:

Ribs provide a means to economically augment stiffness and strength in molded parts without increasing overall wall thickness.

Other uses for ribs include:

• Locating and captivating components of an assembly;
• Providing alignment in mating parts; and
• Acting as stops or guides for mechanisms.

Design Rules for the Rib:

• Thickness – 40% of the wall thickness – 0.4xT
• Height – 5x Wall thickness
• Minimum thickness at top – 0.75mm
• Maximum fillet radii – 0.25mm
• Spacing – 3:1 Steel height/max. width ratio
• Minimum draft angle – 0.5⁰

Methodology:

Creating Rib Surface:

• Extract the Bottom surface of the coin holder

• Create a sketch with extract as the sketch position and a point as the origin.
• Draw lines which act as the profile for extruding the rib with minimum 6mm offset difference between them.

• Extrude the lines separately with tooling axis direction.
• Set extrusion limit as per the design rules, in this case dimension are 12.5mm and 1mm in other direction.

Creating Solid Rib:

• In part design work bench, thicken the surfaces with thick surface command.
• Draft all sides of the rib for 0.5⁰ angle in tooling axis direction.
• Fillet all edges of the rib for 0.25mm.
• And use Boolean command, assemble to join ribs with solid coin holder.

Rib Root Thickness Analysis:

• Create a plane with xy plane and vertex at tooling axis as reference.
• Intersect the coin holder with the plane.
• Measure the height, draft, thickness, thickness at top, spacing between ribs.
• Draw a tritangent circle with extracted fillets and inner face as reference.
• Measure the diameter of the circle.

Draft Analysis:

• Do draft analysis for final component with tooling axis following the general draft analysis procedure.
• To find Draft analysis option, Go to Insert > Analysis > Feature Draft Analysis.

Tree Structure:

Different Views of the Component:

Isometric View:

Front View:

Side View:

Top View:

Conclusion:

Thus, designing the rib for coin holder following the design rules and carrying out rib root thickness analysis are done.