Week 9 - Attachment Feature Creation (Ribs & Screw Boss) - Challenge 1

AIM:

To create a solid body from given class A surface of given door trim component and then to create attachment feature ribs and screw boss.

CREATING TOOLING AXIS:

The direction in which the mould open and closes is called the tooling axis direction.
Check the connectivity of the surface and ensure there will be no gap between the surfaces and then define the tooling axis.

It is nothing but the direction in which the mold opens and closes the draft angle needed to be provided by considering this tooling axis.

We can create a tooling axis by using the bisecting method.

CREATING B SURFACE:

Extract the surfaces from the class A using multiple extract and untrim them. Use Extrapolate to make sure that all the untrims are properly intersected to trim and offset the surfaces to 2.5 mm to create the thickness. Trim the extra surfaces using trim command, insert them into new geometrical set and name it with respective part names. Apply fillets to the model after creating the entire surface. If the edges are outside the fillet value will be added to the thickness of the component and if the edges are inside, the fillet value will be subtracted from the thickness of the component, for instance the thickness of the component Is 2.5mm the fillet value is 15mm so the outside portion value should be 17.5mm and inner eges should be filleted 12.5mm to get uniform thickness. Perform trims one at a time so that it will be clear to understand.

CREATING C SURFACE:

C surface is created between the class A and class B surface to close the open boundary. It is created from the boundary lines of class A surface and by extracting the supporting surfaces then sweep the boundary lines with reference to the extracted surfaces.In order to get the C surface first we have to create a boundary lines of class A surface or by using multiple extrapolated command and check for the continuity of it.

Create a sweep with reference to the curve and the reference surface with a 90 degree angle and give the inside direction Check for the continuity of the surfaces if there is any gap go for extrapolated and trim all together now we will get the class C surface.

Then join the class A surface and C surfaces together by join command then check it for connectivity of the surfaces if it is ok then finally trimmed it with B surface we will get the final component again check whether the final body is closed by using boundary command.

Closed solid body is created by using the close surface on part workbench by selecting the final Trimmed component and do the draft analysis for the same.

CREATING THE RIB:

Ribs are thin wall protrusions that extend perpendicularly 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 1 mm

The draft is applied to the sides of the ribs. As per the design rule, the ideal draft angle is 0.5 deg, then fillet is applied to the faces of the rib. As per the design rule, the fillet can be 0.25 mm.

CREATING THE SCREW BOSS:

Screw Boss features are commonly found in injection molding designs. They are used to aid in the assembly of molded parts by providing a channel for a screw. Their primary use is to strengthen holes or slots in the surface present in the part model.

For thickness, the design rule is as follows,

Thickness,w=0.6*T

=0.6*2.5

=1.5 mm

Therefore, the thickness of the boss can be 1.5 mm per side.

The draft is given to the boss. As per the design rule, the draft given for screw boss is 0.5 deg, then fillet is applied to the faces of the rib. As per the design rule, the fillet can be 0.25 mm.

DRAFT ANALYSIS: