Attachment Feature Creation (Ribs & Screw Boss)

OBJECTIVE

• To design the DOOR TRIM LOWER Plastic component using the given Class-A surface.
• To create the rib for the Drill Handle considering the design rules mentioned.
• To create the Screw boss for the Drill Handle considering the design rules mentioned.

PROCEDURE

1. Defining a Tooling axis for the Class-A surface

1. Step 1: Check the connectivity of the surface and ensure there is no gap in the class A surface. The boundary command helps by highlighting the boundary of all the edges thus we can visually check for gaps in the class A surface.
2. Step 2: We observe the component from all three principal axes to get an optimum tooling axis direction. In this case, the Y direction is the optimum tooling direction.
3. Step 3: Next we create a point at the center of Gravity of the Drill Handle and create a line along the Y direction. This is the main tooling axis.
4. Step 4: We perform a draft analysis on class A and check the angles of the surface we think will create problems in tooling.

2. Creating Class B surface

1. Step 1: We offset the Class A surface to 3 mm towards the rear of class A.
2. Step 2:We observe a few gaps and discontinuity in the offset surface.
3. Step 3: We use the fill command to repair the patch and join with the surface to get the final B surface.

3. Creating Class C surface

1. Step 1: We use the boundary command to extract the side edge boundaries which won't need a draft to clear the tooling and smoothen the curve. We use sweep with the A surface as the reference surface at an angle of 90 degrees for 4 mm. We extract the edges for a few millimeters to help in trimming.
2. Step 2: We use the boundary command to extract the top edge boundaries which need a draft to clear the tooling and smoothen the curve. We use sweep with the tooling axis as the draft direction and with draft angle as 3 degrees towards the out for 4 mm.
3. Step 3: We trim all four surfaces together to create the final C surface.

4. Creating the hollow surface part

1. Step 1: We use the join operation to join the Class A, and C surfaces and trim them with Class B surface into one body to get the final surface body.

5. Publication of the Tooling axis, Class A, B, and C surfaces

1. Step 1: We select the tooling axis, class A, B, and C surface from the tree and go to Tools->Publication to publish them.

6. Creating the final solid component

1. Step 1: We switch to the part design workbench and use the Closesurface feature to create the solid part out of the hollow surface body.

all views

7. Draft analysis on the final component.

1. Step 1: We open the draft analysis command box, select the compass, drag, align it with the tooling axis, and lock it.
2. Step 2: We analyze the color scale and input 2.9 degrees as the draft value and save the analysis.

8. Creating the Ribs

1. Step 1: We create a line for the ribs and extrude it as per the design rule i.e., <= 15mm(<=5t).
2. Step 2: We create a body and in part workbench, we thicken the surfaces for 1.2 mm (0.4t)
3. Step 3: We draft the ribs for 0.5 degrees along the tooling direction.
4. Step 4: We snip and assemble the ribs with the extract of the inner surface of the handle. We fillet all rib edges for 0.25 mm.

9. Creating the Screw Boss

1. Step 1: We create a positioned sketch for the two screw bosses considering M6 screws i.e., the inner diameter is 5.2 mm and as per the design rule, the outside diameter is of 8.8 mm (OD=ID+(2*0.6t)).
2. Step 2: We pad the sketch for a height <= 15 mm (<= 5t).
3. Step 3: We also draft both the inside and outside surfaces of the bosses and assemble into the main body.
4. Step 4: We fillet all rib edges for a maximum radius of 0.25 mm.

TREE STRUCTURE

DRAFT ANALYSIS

1. For the final plastic component

All views

2. For the B-side features

all views

3. For the Class A Surface

All views