Week 8 - Challenge 3 - Coin Holder Design

Aim:

To be able to model solid from the given Class a surface, and perform Draft analysis and create Tooling axis.

Class A surface with tooling axis.

Draft Analysis :

The Draft angle is the amount of taper for molded or cast parts perpendicular to the parting line. It can be measured in degrees. A functional part for injection molding has to have drafts facing both cavity and core sides to reduce the risk of damage to the parts and ensure ejection. And also important is to overcome the vaccume forces by letting air in between the metal and the plastic for the part to release properly. Adding maintaining a decent cosmetic finish.

B SURFACE

• In the case of Class A the surface below is called core and the surface above is called cavity.
• Class A is an aesthetics surface and class B is an engineering surface.
• B surface should be inside the class A surface.
• B surface can be divided into four surfaces the side walls, top walls, outer flange and the base surface and later trim them altogether.
• First step is to create the side wall surfaces by extracting the required surface from Class A and untrimmed it thus we will get a single surface which will be extrapolated to get the required size and finally offset it to the inner side of class A as per the thickness of the material and trim them together and apply the required fillet by measuring the values from class A.
• Base surface of the component is then extract, untrimmed, extrapolated, offset and trimmed.
• The top walls can be directly extrapolated from the extracted surfaces and offset it for the required size of the material.
• Then join the base, side wall and top wall by trim operations.
• As the Outer flange is surface complex it can be divided into two parts and extract them then go for extrapolation, offset, split and join operations and finally check the for the connectivity by intersecting method.
• Now all the four geometries are trimmed together to get the B surface.
• Fillet is applied to the required surfaces by measuring the fillet value from the class A surface.

C SURFACE

• C surface has been created from the boundary lines of class A surface and by extracting the supporting surfaces then sweep the boundary lines with reference to the extracted surfaces.
• In order to get the C surface first we have to create a boundary lines of class A surface or by using multiple extrapolated command and check for the continuity of it.
• Create a sweep with reference to the curve and the reference surface with a 90 degree angle and give the inside direction Check for the continuity of the surfaces if there is any gap go for extrapolated and trim all together now we will get the class C surface.
• 

Then join the class A surface and C surfaces together by join command then check it for connectivity of the surfaces if it is ok then finally trimmed it with B surface we will get the final component again chek whether the final bodyis closed by using boundary command.

Closed solid body is created by using the close surface on part workbench by selecting the final Trimmed component and do the draft analysis for the same.

COCLUSION: THE FINAL COMPONENT OF COIN HOLDER IS COMPLETED.