Week 8 - Challenge 4 - Bumper

Question:-

Create the Bumper Plastic component through the given Class-A surface. To begin with, the tooling axis for the given Class-A Surface should be created meeting the requirements of the draft angle and at the end perform the Draft analysis on the model.

Take the Thickness of the component to be 3 mm

Answer:-

1. Tree Structure

• Ensure Proper Tree Structure
• Geometrical sets should have a proper name based on the sketches present inside of it
• All the sketches should be created under the Geometrical set
• Use the Close Surface feature to make a solid body from the surface.
• Publications: Use the publication option and publish the below
  • Tooling Axis
  • Class A, B, and C surface

1.Tree structure:-

2.Tooling Axis:-

Steps:-

1. create a point on the bottom surface
2. make a intersecting line and find the bisect line through that YZ axis
3. And it will be zero degree to the surface due to plane surface present on both sides
4. it will be the tooling axis

3. Draft Anlysis (before) :-

• The draft angle is the amount of taper for molded or cast parts perpendicular to the parting line.
• It can be measured in degrees or mm/mm (in/in).
• As plastic cools, it shrinks and therefore shrinks onto molding surfaces.
• Because of this and a few other reasons, we draft (angle) the walls of the plastic part, so as the part is removed it breaks free from the molding surfaces easier and without dragging.
• A functional part for injection molding has to have drafts facing both cavity and core sides to reduce the risk of damage to the parts and ensure ejection.
• What’s also important is to overcome the vacuum forces by letting air in between the metal and the plastic for the part to release properly.
• Adding an adequate draft angle ensures that warpage upon ejection is prevented while maintaining a decent cosmetic finish.

• Draft angles are generally a requirement of injection molding design (though there are a select few soft materials, like nylon, that can get away with draft angles of zero).
• Draft should be a part of design for manufacture, and Plastic Product Designer should be aware of its need at the outset of the design process. This allows considerations for design requirements to be taken into account

• Nominal Values for Draft angle:

  1. 3 Degrees is nominal Draft.
  2. 5 Degrees can also be manufactured. But it will increase the manufacturing cost.
  3. 7 Degrees for textured surface.

  Importance of DRAFT in Injection Molding:

  • Reduces the chance of damage to the part due to friction during release
  • Reduces wear and tear and chances of damage to the mold
  • Ensures a uniform, smooth, unscratched finish when required
  • Ensures the integrity and uniformity of other surface finishes and textures
  • Reduces overall cooling time by lessening or eliminating the need for unconventional ejection setups
  • Most, if not all, of these benefits offer either direct or indirect overall production cost reductions.

  Steps followed for Draft Analysis:

  1. The part created has to be changed to Material mode in display frame.
  2. Compass is enabled. Align compass along with tooling direction.
  3. Lock command is then applied to fix compass along with tooling axis
  4. Color codes are classified and Draft angle is applied.
  5. Running point analysis is used to display permissible draft angle

4. Class A surface (Given):-

5. Class B Surface :-

6. Class C Surface :-

7.Final trim - surface of Coin holder

8. Part body - closed surface:-

9.Draft analysis (final):-

Result:-

• Screenshots of the Draft analysis report for both the given Class-A surface and the final plastic component
• Screenshots of the solid model with the proper color code of the draft angle in various orientations (Isometric, Front, Side, and Top View)
• the given subbmission rules are shown
• thickness of Swith bazel is maintain at 3 mm