Challenge

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

AAkshay Wagh31 Dec 2022

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

Objective :

Create the rib for the Drill Handle considering the design rules mentioned in the video.

Create the Screw boss for the Drill Handle considering the design rules mentioned in the video.

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.

Description :

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,selected the featured draft analysis tool in the Generative shape design workbench. Initially, 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 green colour for > 0.9 deg, red colour for < 0deg

in Draft angle parameter table Gave Value a 0.9deg draft angle to clear every face.

Class A surface Provided:

Class B surface Creation:

To create the class B surface for the door handle, I offset the class A surface to 2.5mm 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'.

Class B Surface:

Class C Surface creation:

I used the sweep command in the geometric shape design workbench to create the class C surface.
Initially, I extracted the edges of the class A surface with tangent continuity by using the multiple extract command. After extracting the class A surface edges correctly, I sweeped the extracted edges with 93deg toward the class B surface. After sweeping the extracted class A surface edges, I extrapolated the edges of the sweep for 2mm to intersect the sweep edges with each other. Now I trimmed the extrapolated surfaces together to create a complete sweep surface towards the class B surface. I joined both the trimmed sweep surface and class A surface together, to get the class A+C surfaces as a single surface. Now, to create a solid body for the door handle we need a closed surface. I trim the class B surface with joined class A+C surface to make the closed surface of a door handle.

Class C surface:

Class A+C surface join:

Closed body:

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, 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.

RIB sketch:

Rib Solid

RIB Root Thickness:

Rib Root Thickness is calculated As By Creating Plane Perpendicular to surface of solid and then using intersection command and selecting components then multi output will get then draw circle by tangent and calculated radius

SCREW BOSS Design:

To create the screw boss, I created the circular sketch in the sketcher workbench and I padded the sketch to 12.5mm. Now, I drafted the inside and outside surfaces with 0.5deg in the tooling axis direction. After creating the screw boss, I gave 0.25mm of the fillet to all sides. Now, I translated the screw boss toward the right side for 35mm. To keep the screw boss stiff and rigid, I created 4 supporting ribs for each screw boss.

Screw Boss sketch:

Screw Boss-1&2

Draft Analysis for the Solid Body:

To perform the draft analysis for the solid part body (which has ribs and screw bosses on it),used the featured draft analysis tool in the generative shape design workbench. Initially,aligned the compass to the tooling axis and selected the solid part body, 0.9deg draft angle, in the colour bar 0.9deg draft angle provided The areas which highlighted in Green the below image are cleared in the 0.9deg draft angle

The areas which highlighted in Green the above-given image are cleared in the 0.9deg draft angle

Ensure Proper Tree Structure Geometrical sets should have a proper name based on the sketches present inside of it A,B,C,A+C,A+B+C Final trim, Closed Body,Solid Body ,Rib Design, Screw Boss Design,All Geomertrical Sets with Part body All ScreenShots