Week 10 - Challenge 1- Attachment Feature Creation (Ribs & Screw Boss)

OBJECTIVE: To create the rib and screw boss for the door handle considering the design rules for the rib creation and screw boss creation and then perform the draft analysis for class A rib,screw boss and final component.

Given: Class A srface.

Software Used:Catia v5

Steps involved while creating Switch Bezel component.

1. Creation of tooling direction.
2. Create class B surface.
3. Create class C surface.
4. Joined A and C surface.
5. Final join all surfaces(A+B+C).
6. Create solid component
7. creation of Ribs
8. Creation of screw boss

1.Creation of tooling direction.

• The direction in which the mould open and close is called tooling direction.
• For tooling axis first we have checked all three axis.
• Then create a boundary of base surface.
• Now create two line on side of curve..
• Then create a bisecting line using Line1 and Line2 and check draft analysis.
• Hence, that line is our tooling axis

2.Create class B surface.

• For creation of B surface we offset class A surface inward by 3 mm which is the thickness of component.
• There are some patches found after offseting.
• we have repaired patches through join ,extrude ,sweep ,multiple extract ,trim,multisection surface command according to need.

Create class C surface.

• Create the boundary of class a surface and by using sweep command create surface.
• Then join all the surfaces.
• Ensure that there is no any gap between the surfaces.

Joined A and C surface.

• Now join A and C surface together.

Final join all surfaces(A+B+C).

• Now trim the A+C surface with B surface.

Create solid component

• Now create a solid component using close surface command.

creation of Ribs

• For creation of proper rib there is some specific rule which should follow suring designing and creating the Rib.

1. Component thickness(T)is taken as 3mm.
2. Rib draft angle =0.5 degree.
3. Rib fillet radius(r) can be = 0.5 >=r<=0.25.
4. Rib thickness =0.4T;
5. Rib tip thickness should be equal to 0.75 or more.distance between two rib should be minimum 3T.

General Guidelines for Bosses:

• Draft - 0.5 degrees on the walls of boss
• Thickness - Typically 40%* of the nominal wall at the base.
• Height to Diameter Ratio - 3:1
• Radii - 0.25mm maximum radii.

Draft Analysis:

1. First the class – A surface is checked before creating the Class –B&C surface and finally the solid body must be analysed. Both can be done by following the below procedures.
2. By changing the view mode to custom view parameters – Material mode then the feature draft analysis is enabled.
3. Then the compass was activated and placed with the tooling axis by dragging the red pointer and then locked it.
4. Then, by selecting the quick analysis mode, the nominal value will be 3 degrees and checked for the component's draft angle and at angle 0.5 degree the ribs and screw boss will check.
5. The green colour area shows that it satisfies the 3-degree draft angle.

Draft Analysis of A surface:

Draft Analysis of solid component ,Ribs and screw boss: