Week 9 - Project - A pillar Design with Master Section
A PILLAR DESIGN WITH MASTER SECTION
- Picture of the sketches with Sketch solving status’s geometry tab
- Picture of the Detailed tree structure
- Draft
In engineering, the draft 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)
- Drafts (or taper) in a mold, facilitate part removal from the mold. The amount of draft angle depends on the depth of the part in the mold, and its required end-use function.
- The draft is in the offset angle in a direction parallel to the mold opening and closing.
- It is best to allow for as much draft as possible for easy release from the mold. The minimum taper angle is 0.5 to 1 degree but 3 degrees is a widely accepted norm.
- The mold parting line can be relocated to split the draft in order to minimize it. If no draft is acceptable due to design considerations, then a side action may be required at a greater expense in tooling.
- Draft Analysis
Displays a color gradient on the faces of selected bodies to help evaluate the manufacturability of your design. Select the bodies to evaluate and the axis to define the direction. Use the options to refine the gradient display. In Catia, we use the feature draft analysis tool for this.
- Tooling Axis for A-Pillar Class A
Tooling Axis is the direction in which the mold or core and cavity open is the tooling axis
Bisector Method: It is a common method used to create a tooling axis for Class-A surface, firstly select the direction in which tooling is difficult there may be one or two directions on a single surface. Then, create an intersecting curve with respect to the surface by taking a plane as a reference and draw lines that coincide with the intersection curve where the draft occurs, then bisect these lines to get the tooling axis. Use this method in another direction if needed. Finally, bisect those axes to get the tooling axis for the surface.
In this case, we use the master section for creating the tooling axis as shown in the figure.
- Class A
- Class B
- Class C
- Draft Analysis of Class-A Surface
Draft analysis with respect to the tooling axis for class-A is showing most of the regions satisfy the minimum 3-degree draft condition, but some portion under 3 degrees and negative draft, is the Class-A defect from the styling team.
- Side Core Tooling Axis
Dog house
Dog house is an engineering feature used in the plastic trim design. Dog houses are used as supporting features. Sometimes other engineering features like snaps, locators, etc. are mounded on them to increase their strength. Dog houses are subjected to draft analysis to prevent breakage of the component during ejection from the mold cavity. Dog house and other engineering components are built on B-surface. The figure shows the side core tooling axis for the Dog house.
- Draft Analysis of Dog House (Side Core Axis)
The inner draft for the dog house and rib is 0.5 degrees and this draft analysis wrt the side core axis shows that the draft is more than 0.49 degrees, we give 0.49 degrees because there might be some portion that slightly varies from the 0.5 degrees.
- Draft Analysis of Dog House (Tooling Axis)
The outer draft for the dog house is 1.5 degrees and this draft analysis shows the draft for the dog house is more than 1.49 degrees, we give 1.49 degrees because there might be some portion that slightly varies from the 1.5 degrees.
- Draft Analysis of Final Plastic Component
Draft analysis for the final component shows that most of the regions are more than 2.9 degrees draft and some are less than 2.9 degrees and certain regions are negative also. The minimum draft is 3 degrees actually but at Class-C surface there are some points that are varying values between 2.9 and 3 degrees that why we take 2.9 degrees for draft analysis.
- Picture of the 3D CAD
1. Isometric View
2. Front View
3. Side View
4. Top View
