Challenge

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

SSeenivasa Perumal6 Jun 2023

Tooling axis:

To create the tool axis, I extracted the class A surface without spreading and created a point in the center of the extracted surface and created a line in the Y direction at that point. After creating the tool axis, I performed a chamfer analysis for class A to check the chamfer angle for it.

Draft Analysis for Class A Surface:

To perform a bevel analysis in class A, I selected the recommended bevel analysis tool on the generative shape design workspace. First, I click on the "use compass to define new current bevel direction" command to align the compass to the tool axis.

Once the compass is aligned with the compass in the tool axis, we need to select the surface to perform the chamfer analysis. The Class A surface will be highlighted (in green) according to the angle of the color bar and the colors we defined in it.

Here I have given green color for > 0.9 deg, red color for < 0 deg and cyan color for less than 0.9 deg and greater than 0 deg.

If I set the bevel angle to 3°, some surfaces would not be cleaned, so I gradually decreased the bevel angle until all surfaces would be cleaned.

The angle of immersion is 3 degrees:

To clear the faces which are not cleared with a 3deg draft angle, I gave a 0.9deg draft angle to clear every face.

The draft angle is 0.9deg:

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 creation:

Creating a class C surface:

I used the drag command in the geometry design workspace to create a class C surface.

I initially extracted the edges of the class A surface with tangent continuity using the multiple extract command. After properly extracting the edges of the Class A surface, I swept the extracted edges 93 degrees towards the Class B surface. After retracting the edges of the extracted Class A surface, I extrapolated the edges of the stroke to 2 mm so that the stroke edges intersect each other. Now I clipped the extrapolated surfaces together to create a complete sweep surface towards the class B surface. I joined the clipped drag surface and the class A surface together to get the class A+C surfaces as one surface. Now, to create a solid body for the door handle, we need a closed surface. I trim the surface of class B with the combined surface of class A+C so that the closed surface of the door handle is created.

Class C surface:

Class A+C surface join:

Closed body:

RIB design:

To create the fins on the body of the solid part, we need to follow the design guidelines above. First I create a line sketch for the rib and extrude it in the direction of the tool axis and thicken the extruded surface to 1mm inwards,

after reinforcing the extruded surface, i gave the rib a 0.5 degree bevel angle and joined the rib to the body of the part to remove the extra surface of the rib, by joining the trim of the rib to the body of the part, the rib will be added to the main body without the unwanted extra part. After adding the rib to the body of the part, I gave a rounding to the rib with a radius of 0.25 mm (according to the design parameters, the maximum rounding radius is 0.25 mm). I created rib-2 in the same way.

RIB sketch:

RIB_1

RIB-2:

RIB Root Thickness:

To check the rib root thickness, I created a plane which is perpendicular to the base surface (if the plane is parallel to the base surface the intersection will be taken, but we can't see any rib intersection on it, so that is why the plane is created perpendicular to the base surface). After taking the intersection for the body and plane, we need to create a tri-tangental circle at the bottom of the rib. To create the circle, we need to extract the faces of the intersection (if we directly select the faces without extracting the required faces the input may take the entire intersection surface as an input) which we need to give as input for the tri-tangental circle. The tri-tangental circle is shown below, with the measurement of it.

SCREW BOSS Design:

To create the bolt head, I created a circular sketch in the sketchbook workbench and padded the sketch to 12.5mm. I have now drawn the inner and outer surfaces with 0.5 degrees in the direction of the tool axis. After creating the screw head, I put a 0.25mm round on all sides. I have now moved the bolt attachment towards the right side by 35mm. To keep the bolt attachment stiff and rigid, I created 4 support ribs for each bolt boss.

Sketch of the Boss screw:

Screw Boss-1:

Screw Boss-2:

Screw Boss supporting Ribs sketch:

Screw Boss supporting Ribs:

Draft Analysis for the Solid Body:

To perform the draft analysis for the solid part body (which has ribs and screw bosses on it), I used the featured draft analysis tool in the generative shape design workbench. Initially, I aligned the compass to the tooling axis and I selected the solid part body, I gave a 0.9deg draft angle in the colour bar. If I gave a 3deg draft angle in the colour bar some faces are not clearing properly, due to the class A surface draft angle and curvatures on the bottom area the solid body has shown in red and cyan colours even though we gave 0.9 deg in the draft angle in the colour bar we can't decrease the draft angle to less than 05deg because the draft angle for the plastic component is 0.5deg to 3deg).

The draft angle is 3deg:

In the above-given images, the faces which are highlighted in cyan colour are not cleared properly with 3deg of draft angle.

The draft angle is 0.9deg:

In the above-given images, all the faces are cleared properly except in the bottom area, this is due to the curvature at the bottom area on the class A surface. The curvature area is given below.

The areas which I highlighted in the above-given image are not cleared in the 0.9deg draft angle also due to the curvature on the class A surface.
The below-given image visualizes the curvatures on the class A surface

Class A curvature:

Solid part body curvature:

Draft analysis check for Screw Bosses:

I inversed the draft direction and reduced the draft angle to less than 0.5deg (because the screw boss and rib draft angle is 0.5deg maximum) to check whether both the sides of the screw boss and ribs surfaces are drafted properly or not.

In the above-given image, the draft direction is inversed and the draft angle is set to 0.48 deg to check the draft angle for screw boss and rib surfaces.

Different view:
Isometric view:

Front view:

Bottom view:

Left view:

Right view:

Top view:

Bottom view:

CONCLUSION:

Given Diagram Drawn Successfully and Verified the profile as per given instruction.

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

Ship work like this
in your own course.

Talk to a career counsellor

Ship work like thisin your own course.

Talk to a career counsellor

Ship work like this
in your own course.