Week 9 - Attachment Feature Creation - Challenge 2

AIM:

To create the Screw Bosses for the Centre console coin holder considering the design rules by using Catia V5.

OBJECTIVE:

• Create a tooling axis following the OEM standard
• Making the Rib According design rules
• Part Thickness: 40% NOMINAL VALUE and Draft angle: 0.5 Deg
• Performing the draft analysis to the component

Design Rules for Screw Boss Creation:

• Draft- 0.5 degrees on the walls of the boss
• Thickness is typically 40% of the nominal wall at the base
• Height to diameter ratio= 3:1
• Radius= 0.25mm maximum radii
• Boss gussets must meet rib guidelines

METHODOLOGY:

Creating the Tooling Axis

The tooling direction is used to find the direction in which the part is removed from the core and cavity. The draft angle should be positive to the tooling axis to manufacture the component easily. The step-by-step procedure of creating the tooling axis is given below.

Step: 1

• Creating the point on surfaces respectively also extracts the surface of the component.

Step: 2

• Now creating the intersection to the Z-Y and Z-X direction of the surface as shown below.

Step: 3

• It is symmetry and normal surface, hence we can directly by zero distance value-based to normal to the surface.
• Finally, we get our main tooling axis for the door armrest component.

Creating the Screw Boss on the Coin holder:

Step: 1

• Creating the sketch by extracting the class A surface, by each surface separately, point and axis system created simultaneously on the surface. Using positioned sketch making as shown below.

Step: 2

• The sketch extruded to the surface for minimal distance from the extract of the coin holder as shown below.

Step: 3

• The rib has been created by the same procedure by the sketch and extruding for supporting the screw boss and it is drafted for 0.5 deg.

Step: 4

• It is assembled to the main body and it is filleted for radius 0.25 of smooth edges as shown below.

Step: 5

• Analyzing the Rib root thickness for the coin holder rib by creating an intersection for the model as shown below.

Performing Draft Analysis:

The Draft Analysis command enables you to detect if the part you drafted will be easily removed. This type of analysis is performed based on color ranges identifying zones on the analyzed component where the deviation from the draft direction at any point, corresponds to specified values. This rule of thumb applies to parts with mold depths of up to 2 inches. At this size, a draft as low as 1½ degrees will allow for an easy, non-damaging release from the mold when the expected shrinkage of the thermoplastic material occurs.

It’s also important to remember that draft angles are just one component of an effectively designed injection molded piece. Design for manufacture is one of the easiest ways to improve the quality and efficiency of your injection molding process, and it never hurts to stay up to speed on all injection molding best practices.

Draft Analysis for Screw Boss formation:

Step: 1

• First, we have to set the compass on the main tooling axis to get the direction of the core and part moves along as shown below.

Step: 2

• Once the compass is locked in the axis, directly click on the surface it will appear quality of the draft surface whether it is pass or failed. Here the draft angle is given as 0.5 degrees. Hence we achieved green color on the top surface. Hence it accepts the draft angle for the surface, so we build good quality components.

Step: 3

• Now we check the color variant scale to ensure the maximum and minimum area draft angle is achieved by displaying green, red, and blue colors respectively. If the surface appears red in color while analyzing it is not accepted.

Step: 4

• We can check the angle of the draft given to the surface by using draft tool analysis just point the over the surface where we have checked the angle of the given draft to the component as shown below.

Sliding Tooling Axis:

To analyze the dog house, the slider core tooling axis is needed it done creating a point line definition to the z-axis as shown below.

Creating the Dog Boss on the Coin holder:

Step: 1

• Creating the sketch by extracting the class A surface, by each surface separately, point and axis system created simultaneously on the surface. Using positioned sketch making as shown below.

Step: 2

• The sketch extruded by using sweep option for tooling axis direction from the extract of coin holder or 1.5 deg angle as shown below, the extracted surface from Class A has been offset to make the top surface of dog house by trimming it.

Step: 3

• The swept surface is converted into solid by thicking the surface for 2mm and it is extrapolated.
• To create the draft, first, we have to extract the inner wall surface and it is offset to 2.5mm to make the trim as shown below. The draft angle is 0.5 mm for the dog house.

Step: 4

• The undercut has been made by extrapolated surface and it is offset to the minimal value and it is trimmed to get a perfect undercut.

Step: 5

• It is assembled to the main body and it is filleted for radius 0.25 of smooth edges as shown below.

Performing Draft Analysis:

The Draft Analysis command enables you to detect if the part you drafted will be easily removed. This type of analysis is performed based on col ranges identifying zones on the analyzed component where the deviation from the draft direction at any point, corresponds to specified values. This rule of thumb applies to parts with mold depths of up to 2 inches. At this size, a draft as low as 1½ degrees will allow for an easy, non-damaging release from the mold when the expected shrinkage of the thermoplastic material occurs.

It’s also important to remember that draft angles are just one component of an effectively designed injection molded piece. Design for manufacture is one of the easiest ways to improve the quality and efficiency of your injection molding process, and it never hurts to stay up to speed on all injection molding best practices.

Draft Analysis for Dog House formation:

Step: 1

• First, we have to set the compass on the main tooling axis to get the direction of the core and part moves along as shown below.

Step: 2

• Once the compass is locked in the axis, directly click on the surface it will appear quality of the draft surface whether it is pass or failed. Here the draft angle is given as 0.5 degrees. Hence we achieved green color on the top surface. Hence it accepts the draft angle for the surface, so we build good quality components.

Step: 3

• Now we check the color variant scale to ensure the maximum and minimum area draft angle is achieved by displaying green, red, and blue colors respectively. If the surface appears red in color while analyzing it is not accepted.

Step: 4

• We can check the angle of the draft given to the surface by using draft tool analysis just point the over the surface where we have checked the angle of the given draft to the component as shown below.

ISOMETRIC VIEW

FRONT VIEW

SIDE VIEW

TOP VIEW

Conclusion:

The creation of the Dog House on the coin holder has been successful done by the guidance of design rules. It has been converted from the surface into a solid body. The tooling axis has been created according to the OEM standard. Drafting Analysis has been performed and results have been updated in step-by-step methodology.