Week 10 - Challenge 3 - Door Trim Lower with Engineering Features

Door Trim Lower (Heat Stakes & Locators)

Aim -

• Createthe Door trim lower component of 2.5mm thickness and give it the Heat Stakes and Locators at required locations, considering the design rules.
• Perform Draft analysis on the Class A surface, final part and the Dog House attachments.

Reference Image -

Design Of Door Trim Lower -

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.
   - Break the complex boundaries into smaller, more manageable boundaries and create swept surfaces.
   - 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.
   - Or use the Surface as reference and provide the angle & direction to the created surface.

6. Join the Class A and Class C surfaces.

7. Make sure the Class A&C join intersects completely with the Class B Surface, if not Extrapolate the Class B 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 Closed-Surface Command in Part workbench to create the solid Door Trim Part.

Design Of 4-Way Locators -

Locators are used to arrest/restrict the motion of component (by restricting it’s degrees of freedom). The design requirements for a Locator is similar to a Rib :

- O.5 deg draft for all faces.
- 0.3 deg edge fillets.
- Thickness of surface is 0.6 times the thickness of component and the top face must have at least 0.75mm width.

- Height can be adjusted taking into consideration the minimum requirements.

• Positioned iso-constrained sketches are to be created at a plane on the surface at which the locator is to be positioned.

• Design the profile and then extrude the profile and thicken it as a separate Body in using part workbench.
• Provide draft for all required faces.
• Chamfer the sharp edges to form an entry point for the locator into the counterpart surface.
• Create points on surfaces at positions where Locators are to be fixed.

• Use Copy> Paste-Special Part with link> Translate commands in part work bench to position all Locators.
• Assemble all Locators into one Locator PartBody.
• Union Trim the Locator part body onto the Door Trim Lower component and choose the faces to keep.

Design Of Heat Stakes -

Heat staking also known as thermoplastic staking is the process of joining two dissimilar plastic materials together. In heat staking, local heating is used to raise the temperature of plastic components and allow it to be welded together. The components that is heated and pierces the part is called Heat Stakes. The design requirements for Heat Stakes are :

- 1.5deg draft on the face.
- 0.5deg edge fillets.

- Height should be less than the height of Locators.

• The positioning points for the Heat stakes are already provided

• Create an iso-constrained sketch at one of the points given positioned on a plane on the Class B Surface.

• Design the profile and then extrude the profile and thicken it as a separate Body in using part workbench.
• Provide draft for the required face.
• Use Copy> Paste-Special Part with link> Translate commands in part workbench to position all Locators onto the given points.
• Assemble all Locators into one Heat Stake PartBody.
• Union Trim the Locator part body onto the Door Trim Lower component and choose the faces to keep.

Tree Structure -

Final Door Trim Lower with Engineering Features -

Isometric View :

Front View :

Side View :

Top View :

Draft Analysis -

Class A Surface :

Hollow Closed Surface :

Locators :

Heat Stakes:

Door Trim Lowe Part-body :

Result And Conclusion -

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