Week 9 - Attachment Feature Creation - Challenge 2

Aim:

Create the Screw boss and Dog House for the Centre console coin holder considering the design rules.

Introduction:

Screw Boss:

Screw bosses are used for the purpose of registration of mating parts or for attaching fasteners such as screws or accepting threaded inserts

Dog House:

Dog house is an engineering feature used in plastic trim design. Dog houses are used as supporting feature. Sometimes other engineering features like snaps; locators etc. are mounded on them to increase their strength.

Design Rules for the dog house:

• Thickness - Doghouse wall thickness at the intersection of the part wall (C) should be 40% or less than the main wall stock (T)
• Height – Height of (B) should be between 3.0 – 6.0 mm

Methodology:

Create Screw Boss:

• Extract the Bottom surface of the coin holder
• Create a sketch with extract as the sketch position and vertex of main tooling axis as the origin.
• Draw two concentric circles and constrain them which act as the profile for extruding the boss.

• In part design workbench, Pad the sketch for 12mm and 1 mm for the other limits.

• Draft the face of pad for 0.5mm and extracted bottom surface as neutral element and main tooling axis as pulling direction.
• Create a sketch with extract as the sketch position and vertex of main tooling axis as the origin.
• Draw two lines which are 20mm long and perpendicular to each other and their midpoints coincide at the center point of the circles created in previous sketch.

• Pad the sketch for 10mm and 1mm for other limits, make sure to check the thick feature while padding and 1 mm for thin pad with neutral fiber.

• Draft all face of pad for 0.5⁰ and extracted bottom surface as neutral element and main tooling axis as pulling direction.
• Union trim the Screw boss and its gusset select the faces to remove and the assemble the screw boss to coin holder.
• Create the fillet for 0.5mm on all faces.

Create Dog House:

• Create a plane with ZX plane and a point.
• Create a sketch using the above plane and draw a profile for the dog house.

• Sweep the profile for 21mm and 1.5mm long with main tooling axis as draft direction at an angle of 1.5⁰

• Extract and untrim the bottom of class A surface.
• Offset the extracted class for 2.5mm.
• Again, Offset the surface for 20mm and trim the offset with sweep.

• In part design workbench, use thick surface command for the trimmed surface.

• Draft the inner faces of the solid for 0.5⁰ using side core as pulling direction.
• Create fillets on the outer face for 3mm and 1mm for inner faces.

• In generative shape design, Extract the inner faces with tangent continuity.
• Offset the extract for 1mm outwards and also offset the class A surface extract for 4mm.

• Trim the above two offset surfaces.

• Split the surface with body.

• Draft the face obtained for 0.5⁰ using side core as pulling direction.
• Fillet the edges for 0.5mm.
• Assemble the dog house body to the coin holder.

Create Side Core Axis:

• To create a side core axis, create a line in Z direction by using the previously created point which is used to create main tooling axis.
• Side core axis will be created perpendicular to the main tooling axis.

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, creating the Screw bosses and Dog House for the Centre console coin holder considering the design rules are done successfully.