Week 8 - Challenge 4 - Coin Holder Design

COIN HOLDER DESIGN

JEEVA R

AIM: To make a coin holder model from the provided class-A surface.

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.

METHODOLOGY:

In this model we have focused on the following things:

1. Tooling axis
2. Draft analysis
3. Class-B surface
4. Class-C surface
5. Making a solid model from surface.

Following tools were used to reach the final step:

1. Extract
2. Un-trim
3. Trim
4. Extrapolate
5. Offset
6. Edge fillet
7. Boundary
8. Sweep
9. Join
10. Close (part design)

FOR DRAFT ANALYSIS:

1. First, we analysis the model and then choose dummy axis in x and y direction.

2. As we intersected to proceed, we observed that the side walls are not given any draft. Hence, we assume the axis normal to the base surface and parallel to side walls. This surely will create problems because a minimum draft has to be provided.

3. As class-A surface is made by other designer only he is authorized to make changes, so we look over this to complete the coin holder for practice.

4. Now we go to insert< analysis< draft analysis and follow usual procedure to do the analysis.

5. Align the compass and click on the surface and as expected the model is mostly in red color i.e., negative draft with respect to the axis.

6. To correct it to as best as we can we moved the compass a bit till we got most of the surfaces in green and lock that position.

7. After hitting ok, we change the direction of the line from z axis to compass direction. The axis will align itself accordingly.

NOTE: As the side wall does not have draft, this result was expected and few areas need correction in class A surface. But still, we are moving forward to complete the model.

FOR CLASS-B SURFACES:

1. We have divided the entire model into base, side walls, inside side walls and outer flange and worked on them one by one.
2. Everywhere we follow same procedure i.e., extract, un-trim, extrapolate, trim and offset.

3. First base, then side walls. To avoid confusion, we trimmed both together and made them one. Also, the fillet was given.

4. Then we move to inside side flange. Here instead of using extract and un-trim we directly used multi-extract and extrapolated it.

5. We nearly do the same procedure for outside flange. After all these, we get a basic sharp model.

6. We then make all of them one by trimming.

7. After measuring various fillets, we fillet the surface. Remember to keep minimum fillet value as 1mm.

FOR CLASS-C SURFACES:

1. In this model, unlike the earlier models, we have used parallel tooling axis. Hence we cannot use with draft direction' option under sweep.
2. The C surfaces will mostly be created like shown below.

3. Here we will first get the boundary of the class-A surface and sweep it with reference surface option.

4. Similarly, we will get the C surface for the hole to close it.

FOR FINAL MODEL:

1. Join class-A and class-C surfaces together.
2. Then join class-B surface to them.
3. Go to the part design and close the feature.
4. Run draft analysis on the model.

SOLID MODEL:

TREE STRUCTURE: