Week 9 - Challenge 1 - Base Bracket Design
Aim:
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 at the end perform the Draft analysis on the model.
CAD DATA:
The CAD DATA is been given as CATPART, STEP FILE ICES PART
Solution:
INTRODUCTION:
CLASS-A SURFACE: A surface made by the designer which is given as an input to the plastic modeler to work on. It is aesthetic surface and the outer most surface.
CLASS-B SURFACE: A surface below a certain thickness from the class-A surface is class-B surface. This is the surface that contains engineering aspects of a model.
CLASS-C SURFACE: A surface that joins class-A and class-B surfaces is class-C surface.
PROCEDURE:
In this model we have focused on the following things:
Tooling axis
Draft analysis
Class-B surface
Class-C surface
Making a solid model from surface.
Following tools were used to reach the final step:
Extract
Un-trim
Trim
Extrapolate
Offset
Edge fillet
Boundary
Sweep
Join
Close (part design)
TOOLING AXIS:
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.
Analyse 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.
GIVEN:
STEP 1:
STEP 2:
STEP 3:
STEP 4:
STEP 5:
STEP 6:
STEP 7:
STEP 8:
DRAFT ANALYSIS:
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 (3deg) should be inserted.
PUBLICATION:
Publication of Class-A Surface and Tooling Axis
CLASS-B SURFACE:
Initially extracting the right-side rib using the extract option from Class A surface. Then perform Extrapolate in order to increase the length now trim the surfaces to the required surfaces. Then Offset the surface in order to get the required thickness i.e., 2.5 mm
Similarly, create the left-side rib and get the slanted as well as the flat surface and offset it to the desired value and now trim in order to get the required surface now fillet the surface to the required amount
We can divide the surfaces as shown below. Then we will work on them one by one.
Rib 1
Rib 2
Base surface
Final trim
RIB 1:
Extract 1
Extract 2
Extract 3
Surface untrim 1
Surface untrim 2
Surface untrim 3
Extrapolate 1
Extrapolate 2
Extrapolate 3
Trim 1
Trim 2
Offset 1
We get
RIB 2:
Extract 4
Extract 5
Extract 6
Surface untrim 4
Surface untrim 5
Surface untrim 6
Extrapolate 4
Extrapolate 5
Extrapolate 6
Trim 3
Trim 4
Offset 2
We get
BASE SURFACE:
Extract 7
Offset 3
Surface untrim 7
Extract 8
Surface untrim 8
Extrapolate 7
Offset 4
FINAL TRIM:
Trim 5
Trim 6
Extrapolate 8
Trim 7
Edge Fillet 1
Edge Fillet 2
B Surface
We get
CLASS-C SURFACE:
Boundary 1
Sweep 1
Boundary 2
Boundary 3
Sweep 2
Sweep 3
Join 1
Join 2 (C SURFACE)
TRIM SURFACE:
Trim 8
We get
CLOSE SURFACE:
WE GET
EXPLANATION ON BISECTING METHOD:
Bisecting method is basically use to find the proper tooling axis using the dummy tooling axis. In Bisecting method, bisecting line is used which either bisect the two line or it will show error which means the two lines are parallel to each other. In order to know whether the particular surface is tool able or not we intersect the surface with the respective plane and get a sketch which consist of two lines and with the help of bisecting line option we bisect the line which creates a line at the midpoint of the two lines. Likewise, we create tooling clearing axis for x and y which will be used to create the main tooling axis using the bisecting line option in in the line command.
PUBLICATION:
TREE STRUCTURE:
FRONT VIEW:
SIDE VIEW:
TOP VIEW:
ISOMETRIC VIEW:
