Week 10 - Challenge 2- Attachment Feature Creation (Dog House)

Door Trim (Dog House Attachment)

Aim -

• Createthe Door trim component of 2.5mm thickness and give it the Dog House attachments, considering the design rules and requirements.
• Perform Draft analysis on the Class A surface, final part and the Dog House attachments.

Reference Image -

Design Of Door Trim -

1. Check the Class A surface for discontinuities. Create a suitable tooling axis with a flat surface as reference.

2. Offset the Class A surface by 2.5mm inwards to get the offset surface which is the reference for the Class B surface.
3. Check for discontinuities on the Offset Surface. Repair the erroneous surfaces found, by using extract/multiple extract, untrim, extrapolate, join and trim commands in the Generative shape design workbench.
4. The final surface after this process will be the Class B Surface.

5. Create the Class C surface with the sweep operator.
   - Use the draft axis as the reference for the swept surfaces parallel to the draft axis.
   - Use the Class A surface as the reference for the swept surfaces perpendicular to the draft axis.
   - Break the complex boundaries into smaller, more manageable boundaries and create swept surfaces.
   - Use Multi-section command to generate required surfaces that connect the swept surfaces at complex curved parts.
   - Join all the surfaces, extrapolate the edges of perpendicular surfaces and trim them together to for the Class C.

6. Join the Class A and Class C surfaces.

7. Make sure the Class A&C join intersects perfectly with the Class B Surface, if not Extrapolate the Class B just enough so that it intersects with Class A&C join.
8. Trim the Class A&C join with the Class B surface to get the Hollow Closed Surface.

9. Use the ClosedSurface Command in Part workbench to create the solid Door Trim Part.

Design Of Dog House Attachment -

• Dog houses are designed to avoid sink-markscreated on the Class A surface by screw bosses.
• It alsosolves the length issues when giving screw bosses which is need to be assembled to other components that’s not reachable by normal Screw Bosses.
• It is also useful when perpendicular screw bosses are required on the part to the tooling direction.

Design Requirements :

1. ‘C’thickness should be 40% of the main wall thickness ‘T’.
2. Minimum width of the Dog House at it’s top should be at least12 mm.
3. Height‘B’ should be between 3-6 mm.
4. Minimum draft for the Dog House should be5deg to Side-coreTooling Axis.

Procedure :

1. Create the Side-core Tooling Axis.
   - Create a line using sketch command or normal to the point method, perpendicular to the Main Tooling Axis and passing perpendicular through the open face of the Dog House.

2. Create the profile using iso-constrained, positioned sketch and the given image as reference for the Dog House on a plane normal to the Main Tooling Axis.

3. Sweep the profile with reference to the Main Tooling Axis as draft direction, with 1.5deg draft.
4. Close the open top portion of the Swept surface.
   - Use a surface extruded from a line created on a plane offset to the height of the Dog House from it’s base.
   - Use Multi-section command to create the top face and join it with the swept surface.
5. Create a new Body and Thicken the surface by 2mm.
6. Provide the Draft to the insides of the Dog House with respect to the Side-core Tooling Axis.
7. Provide 0.5deg fillets to the inside edges of the Dog House and 2.5deg fillets for the outside edges.
8. - Extract and offset the base surface on which the Dog House will be fixed by 4mm.
   - Extract the inside surfaces of the Dog House and Offset it by 1mm.
   - Trim the Base offset and inside wall offset to form a profile for the base of the Dog House.
   - Split the Dog House with this surface to form the shape of the base walls.

9. Union trim/Assemble the Dog House onto the Door Trim Surface.
10. Repeat the steps/ Copy-paste the Dog House, for the required regions and location.

Final Door Trim Part -

Isometric View :

Front View :

Side View :

Top View :

Tree Structure -

Draft Analysis -

Class A Surface :

Door Trim Solid Part :

Dog House with Side Core Access :

Final Door Trim Component :

Result And Conclusion -

• The Door Trim component is designed and the Dog House attachments are fixed according to the requirements.
• Draft Analysis is done on the Class A Surface, the Solid Surface developed from the hollow closed surface, The Dog House attachment and the final Door handle part. The results all pass the inspection.