Challenge

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

DDiwakar Rajan9 Mar 2023

ATTACHMENT FEATURE CREATION (RIBS & SCREW BOSS)

AIM:

To Create the tooling axis for the given Class-A Surface meeting the requirements of the draft angle. To Attach B side Features in the component. To perform the Draft analysis on the model.

TOOLING AXIS:

Intersect the yz plane with respect to the class A surface.
Hide the class A surface and create point to point lines on the suspected drafts.
Create bisecting line with the two lines and point to create a tooling axis.
Bisecting lines were used to get the exact medium from the two sides so that maximum positive draft angle can be achieved.
The tooling axis is created for the component by bisecting two axis from x and y planes

CLASS B SURFACE:

For creating the class-B surface the required surface except the offset surface have been extracted and then untrimmed all the surface. Then all the surfaces have been extrapolated to get intersections between them. The thickness of the Door handle is 2.5mm the B-Surface was offset to 2.5 mm and the required trim operations must be carried out.

CLASS C SURFACE:

C surface has been 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.

FINAL CLOSED SURFACE:

RIB CREATION:

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

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 XY plane and the Coin holder component. 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.

SCREW BOSS CREATION:

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.

Design rules consider while creating a screw boss: