Challenge

Week 8 - Challenge 3 - Coin Holder Design

CChetan Muninarayanappa28 Nov 2022

AIM: To make a 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.

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 blue color i.e. negative draft with respect to the axis.

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

IMAGES RELATED TO ABOVE STEPS :

SIDE WALLS

FOR CLASS-B SURFACES
1. We have divided the entire model into side walls, topside walls, outer flange and base and worked on them one by one.

2. Everywhere we follow same procedure i.e. extract, un-trim, extrapolate, trim and offset.
3. First side walls and gave the fillets.

4. Then we move to top walls . Here instead of using extract and un-trim we directly used multi-extract and extrapolated it. To avoid confusion, we trimmed both together and made them one. Also the fillet was given.

5. We nearly do the same procedure for outside flange. To avoid confusion, we trimmed both together and made them one. Also the fillet was given.

6. At last the same procedure with the base.After all these, we get a basic sharp model. To avoid confusion, we trimmed both together and made them one. Also the fillet was given.

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.