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

Objective: The main objective of this challenge is to create the B-side features RIBs and Screw Bosses for a given drill handle.

Overview: Creating the class B and class C surfaces to the door handle, and creating the B side features (RIBs and Screw Bosses) by considering all the design parameters.
Design parameters to create RIB for a plastic component:

Tooling Axis:

To create the tooling axis, I extracted the surface of class A with no propagation and I created the point at the centre of the extracted surface and created a line at that point in the Y direction. After creating the Tooling axis, I performed a draft analysis for class A to check the draft angle for it.

Draft analysis for class A surface:

• To perform the draft analysis in class A, I selected the featured draft analysis tool in the Generative shape design workbench.
• Initially, I click on the 'use of the compass to define the new current draft direction' command to align the compass to the tooling axis.
• Once the compass is aligned the compass to the tooling axis, we need to select the surface to perform draft analysis.
• Class A surface will be highlighted (in green colour) according to the colour bar angle and colours we defined in it.

Here I gave green colour for > 0.45 deg, red colour for < 0deg and cyan colour for less than 0.45deg and greater than 0deg.
If I gave a 3deg draft angle some faces are not getting cleared, so I have gradually reduced the draft angle to up to every face gets cleared.

The draft angle is 3deg:

Class B surface Creation:

• To create the class B surface for the door handle, I offset the class A surface to 3mm inside.
• Once the class A surface is offset created, according to the thickness, we can observe some patches on the offset surface due to the fillets on the class A surface.
• Now, we need to close those patches. I used multi-section solid command to close the patches.

Class A offset:

Offset patch:

I observed only one patch on the offset, I used a multi-section solid command to close the patch to create the proper 'Class B surface'.

extrapole the entire boundaries with 2mm

Class B Surface:

Class C Surface creation:

• I used the sweep command in the geometric shape design workbench to create the class C surface
• create the boundaries for the from the class A surface
• sweep the boundaries with 90 deg
• some of the sweep faces with 3 deg
• trim all sweep to create C surface

final trim

join class A +C

join AC+B

Creating Solid body:

• To create the solid body I used the closed surface command in the part workbench.
• Click on the closed surface command in the part workbench and give the closed surface as an input to create the solid part body.

Solid Body:

RIB Design:

• To create the ribs on the solid part body, we need to follow the above-mentioned design guidelines.
• Initially, I create a line sketch for the rib and I extruded it in the tooling axis direction and I thicken the extruded surface to 1mm toward the inside,
  after thickening the extruded surface I gave 0.5deg of draft angle to the rib, and I union trim the rib with the part body to remove the extra surface of the rib, by union trimming the rib with the part body the rib gets added to the main part body without the unwanted extra part.
• After adding the rib to the part body, I gave the fillet to the rib with a radius of 0.25mm (as per the design parameters 0.25mm is the maximum fillet radius). In the same way, I created the rib-2.

Sketch Used For Rib Creation

Sketch Used For Screw Boss Creation

draft analysis

geometrical tree structure

CONCLUSION:

• The Tooling axis and the SolidCAT part with B Side Features is created from the given Class A Surface and Draft Analysis is Performed.