Week 8 - Challenge 3 - Coin Holder Design
Q) Creation of Coin Holder Body with Draft angle
1) Design Check - This includes the checking the given Class A surface for any gaps at the boundaries. There should be no gaps between the surface boundaries.
(i) Given Class A Surface
To perform design check operation, select boundary command and click on the given Class A surface.
Open surface edges are highlighted in green color, as observed from the figure, there are no surface gaps between boundaries. Therefore, this Class A Surface can be used for further operations of creating tooling direction, Class A , B and Solid body.
2) Creation of Tooling Direction
For tooling axis creation, all the axes directions i.e., x,y and z directions are to be checked for easy removal of the mould and low tooling costs.
the above figure shows X,Y and Z directions among which one could be tooling direction or could be found using bisecting method.
(i) Feasibililty Check in all directions
X direction
Z direction
Y direction
Among all the directions, Y direction is the most preferable as the bin part of the class A is perpendicular to the Y axis.
(ii) Creation of Tooling Axis by Bisecting Method
To create a tooling direction, bisecting lines are created using the faces that are closely parallel or at positive draft angles to Z direction. Bisecting lines are created by intersecting YZ (X direction)and XY (Z direction) planes on the Class A Surface. A final bisecting line is created using already generated bisecting lines along their respective planes. This final bisecting line is the Tooling direction.
(a) X direction
The face that is perpendicular to Y direction can be easily cleared, the faces that are closely parallel to Y direction are at a positve draft angle are considered to create a bisecting line. A sketch of YZ plane is considered and is intersected with Class A Surface. A bisecting line generated using the faces that are at a positive draft angle w.r.t Y.
The following images show the positive draft angle made by the faces w.r.t preferable tooling direction.
The following image shows the bisecting line or mean generated using the faces with positive draft angle.
(b) Z direction
The face that is perpendicular to Y direction can be easily cleared, the faces that are closely parallel to Y direction are at a positve draft angle are considered to create a bisecting line. A sketch of XY plane is considered and is intersected with Class A Surface. A bisecting line generated using the faces that are at a positive draft angle w.r.t Y.
The following images show the positve draft angle made by the faces w.r.t preferable tooling direction.
The following image shows the bisecting line or mean generated using the faces with positive draft angle.
(c)Tooling Direction
The tooling direction is obtained by bisecting the above two bisecting lines.
3) Draft analysis
Draft analysis is performed on Class A surface to obtain the Main Tooling Axis. Materials option in customize view should be active before performing Draft analysis. Click on Draft analysis, a color code variant dialog box appears displaying colors, green for positive draft angle, the nominal draft angle for industrial applications is 3 deg. Therefore, 3 deg is provided, the red color indicates a draft angle between 3 and 0. The blue color indicates a negative draft angle.Click on the the compass option on the dialog box , click on the compass and drag it and align it onto the bisector, now click at any point on the surface. The entire surface on topside appears green, this indicates that all the faces can be cleared easily and the bisector created can be considered as the Main tooling axis.
Draft Analysis on CLASS A SURFACE
As observed from the figure, all faces are not clearing, some faces have a draft angle in between 3 and 0 (Red color),
some faces have a negative draft angle (Blue color). To solve this, the Tooling axis has to adjusted using trial and error in such a way that all faces are cleared (Green color).
Possible reasons for the non clearance of faces in obtained tooling direction
(i) For generation of bisecting line, not all faces were considered with draft angles
The lines marked with red were considered for generation of bisecting lines and lines marked with green were not considered in respective planes YZ and XY.
(ii) Visibility of all faces normal to tooling direction
As observed from the figure, all faces are not visible as seen along the normal to the obtained tooling direction, this indicates that the obtained tooling direction is not the ideal one.
Trial and Error method
Let the Y direction be considered as a new tooling direction, a normal to the XZ plane is generated passing througth the projection point.
Checking for Draft analysis _ DRAFT ANALYSIS ON CLASS A SURFACE with color code variant
It is evident that all faces are clearing (Green color), therefore, chosen Y direction is exact and ideal to be the new tooling direction.
As observed from the above figure, all faces are visible along the normal to the tooling direction. This also indicates the chosen direction is an actual tooling direction.
DRAFT ANALYSIS ON FINAL PLASTIC SOLID BODY
The Draft analysis on Solid Body with color code variant can be observed from the above figure. It can be observed from the figure that all faces that are green in color are cleared with a draft angle of 3 deg.
Views of final plastic component
Isometric view
Top view
Front view
Left side view
Right side view
