Project

BASE BRACKET

SS Sujith28 Mar 2023

Objective: To Create the Base Bracket Plastic component through the given Class-A surface. To begin with, the tooling axis for the given Class-A Surface should be created meeting the requirements of the draft angle and to perform the Draft analysis on the model.

CLASS-A Surface

Class-A surface means visible surface. It gives the aesthetic of the component which is created by the styling team and gives to the part design engineer to create the part with all engineering aspects.

CLASS-B Surface

Class-B surface means the thickness of a part it is not visible and is inside part. In other words, the Class-B surface is a surface below a certain thickness from the class-A surface. This is the surface that contains engineering aspects of a model.

CLASS-C Surface

The surface that joins class-A and class-B surfaces are class-C surfaces. Class C is often specified for interior surfaces not readily visible, surfaces that will be covered by another part when assembled

Tooling axis: The direction in which the mold or core and cavity opens is the tooling axis

FOR TOOLING AXIS:

CREATE POINT WITH THE HELP OF CIRCLE ELIPSE COMMAND IN POINT OPTION
TAKE A LINE DRAW LINE WITH THAT CIRCLE AND MAKE IT BOLD AND DOTTED..

First ensure the class-A surface is properly joined and has no discontinuity on it. For this we can use boundary command or join command.

Analyze the model manually or visually to see which direction is most suitable for tooling axis.

As in 3D view we can see 2 holes and a flat surface, we can directly take the tooling axis perpendicular to that. But to be sure,let us analaze from all the views. The below images of the front side and top views shows the areas that we have to keep in mind while choosing tooling axis. As from X we cannot see one hole so we cannot take axis along this. In Y we cannot see any holes so here too we cannot take tooling axis. But in Z we can see 2 holes and flat surface so we can take tooling axis.

Intersect the ZX plane of the axis system with the input and we can see that there is no surface that can create problem during tooling in this direction.

Intersect ZY plane and we are unsure of these two surfaces, so we make a line and bisect them both and this will be our tooling axis which, not so surprisingly, is the same as our guessed tooling axis.

YELLOW DOTTED LINE IS TOOLING AXIS

PERFORM THE DRAFT ANALYSIS-1:-

Make sure the view mode of the part is in material shading

Then do to insert the menu and insert the featured draft analysis tool

Pick the compass and align it with the tooling axis by dragging it.

Then lock the draft direction and perform draft analysis by clicking on the component.

The green color shows the positive daft tooling direction and the given surface passes the draft analysis.

Click on the analyses under the running point to check the draft analysis on the individual faces. It shows how much draft on specific points when we move the cursor point.

Representation of Color variations in the draft analysis

GREEN COLOR - Positive Draft (3 degrees)

RED COLOR - 0-degree draft

BLUE COLOR - Negative Draft

Creating the Class-B surface

Procedures followed for creating the Class-B surfaces are

Extract the ribs from the class-A surface one by one.
Untrim the extracted surfaces
Extrapolate the untrimmed surfaces with a required length
Trim the extrapolated surfaces to achieve the desired rib shape
Then offset the trimmed surface to 2.5mm downwards

Create a slant surface

Extract the slant surface from the class-a surface
Untrim the extracted surface
Extrapolate the untrimmed surface

Create the base surface

The same procedure followed for the slant surface creation is implemented.

After creating all the required faces and surfaces perform the final trim and give the required fillets on the edges resulting in the final class-B surfacE

Creating the class-C surface

The first step is to create the boundary of the CLASS-A surface using the boundary command.

Then using the sweep command create the CLASS-C surface

Then join the CLASS-A surface with the CLASS-C surface using the join command

FOR DRAFT ANALYSIS-2:

Go to insert,analysis, feature draft analysis.
Align the tooling axis with the compass.
Click on the surface and see that the surface is within the permissible limit of the draft values.
The surface should be green and in the column proper value (2.9deg) should be inserted.
Changee the colurs red as blue and blue as red.