Week 9 - Attachment Feature Creation (Ribs & Screw Boss) - Challenge 1
DOOR HANDLE
TOOLING AXIS
By overlooking the component we can make a assumption that the most easiest way for the cavity and core to open. Selection of the direction of tooling axis depends on the ease at which components can be easily ejected.
By analyzing the component the most easily ejectable direction is somewhere close to the Z direction, (might be inclined to it) so we have made a sketch on the YZ plane of Axis System to create a bisecting line considering the 2 faces which might be difficult to be tooled.
DRAFT ANALYSIS
It is a method used in designing to check whether the component created in CAD is manufacturable based on the draft conditioned applied. The main reason behind the draft analysis is the part manufactured should be easily removed from the mold. It also gives an idea of the draft angle from the tooling direction. Here we are giving a tooling direction in order to eject the component easily from the tool. The ideal draft angle given in automotive industries for plastic components is 0 to 3 degree's.
Some of the components where draft analysis is done are hood, Fenders, roof, side doors, etc.
The draft analysis is an important tool as it helps the user to analyze the draft analysis in CATIA uses the color codes for the identification of the draft. Each color has its own meaning for the minimum draft negative draft and under draft.
The draft analysis toolbar provides two models for analysis of the draft, first is the quick analysis which basically has three colors for analyzing Green, Red, and Blue on the other hand other option is the full analysis mode which enables a few more details into the draft and is used in the complex components like the instrument panel, etc. In the above challenge, we have used the quick analysis made for analyzing the draft here. Now, bring the compass and align it with the tooling Axis and click the lock button in the dialogue box.
B SURFACE
In this particular Class A the thickness isn't given so we can assume the thickness to be 2.5mm and simply offset the Class A surface to 2.5mm To create the Class B surface as we can see that after offsetting the surface there's no missing patches so now we can just move on and extrapolate the Class B surface a little so when we trim the Class B surface with Class A + C there's no issue in Trim command.
CLASS C SURFACE
Extrat the boundary from Class A surface using boundary command, now we can easily perform the sweep command with the boundary.
Use sweep command > choose profile type line > subtype as with draft direction > choose guide curve and draft direction > draft angle as 87 degree > preview.
After getting the sweep use the join command to join Class A surface with Class C surface.
After that use the trim Command to trim the Class B surface with Class A + C to get a close surface.
CREATING THE RIB
Ribs are thin wall stick out that extended extended particularly from a wall or plane. They are usually found in clusters offering support to a plane that would have otherwise been too thick, but can also be stand - alone support for a single wall. They are commonly used to provide additional support and strength to a part. Thickness and location are essential to RIB design.
First, the base surface where the RIB has to be created is extracted using the Extract command. A positioned sketch is created and the profile for the RIB is drawn.
Next, the profile is extruded, to find the height, h=Wall thickness*5
= 2.5 * 5
= 12.5 mm
Therefore, the height is 12.5 mm
The extruded surface is thickened,
Thickness, w= 0.4*t
= 0.4*2.5
= 1mm
Therefore, the thickness of the RIB is 1mm
The draft is applied to the sides of the ribs. As per the design rule, the ideal draft angle is 0.5 deg.
The fillet is applied to the faces of the RIB. As per the design rule, the fillet can be 0.25mm.
Now, we have to check for the RIB root thickness.
To check for the RIB root thickness, We have to take an Intersection with the YZ palne. Once we get to the intersection we have to create a tri - tangent circle at the RIB area and measure it. The value must be within 30% greater of the wall thickness.
B SIDE FEATURES CREATION
RIB CREATION
Design Principle for Rib Creation
3D MODEL
Isometric View
Side View
Top View
