Week 9 - Project 1 - Door Applique Design with Engineering Features

A class-A surface from a vehicle door is provided to me to design a part model and validate it.

From this Door Applique as a Class - 'A' surface, first I need to check whether the surface has some boundary irregularities and any open boundaries.

• After checking I need to create a Tooling Axis for the Class - 'A' surface. And also if I need to create the Side core tooling axis for the surface.
• Then I need to create the Class - 'B' and Class- 'C' surface with the help of the Class - 'A' surface.

Tooling axis creation

  The tooling axis is the direction of drawing a sheet metal where the finished component is easily ejected on a particular direction and axis. The tooling axis is important for removing the material when finished. 

• First, I will create An Axis system, from that axis system I will get two cross-sections. by using that cross-section lines I will create the tooling axis for the surface.
• Or, if it is a flat surface I will create a point using surface and create a line using the Axis system.

• Now performing Draft analysis to check whether the tooling axis has some negative draft

there Is no negative draft on the provided class A surface.

Creation of Class - B surface

extracting the class - A surface without the fillets and then trimming and extrapolating them to join them, and after that offset the surface to 2.5 mm thickness which forms as the Class - B surface.

Class- B surface with fillet

Class - C surface

By extracting the boundary of the class - A surface, the surface required for class - C is obtained.

Trimming and joining all the class surfaces together

Final output

Draft Analysis report

When a plastic component is made, we can observe a draft angle given on each side from the base that is lesser than 90 degrees. This is because in the criteria of making a plastic material the mold should release the material when finished. if the mold surfaces are 90 degrees the material won't release from the mold because of friction due to contraction of material when cooled.

To resolve this problem we CAD engineers maintain a standard rule to design the plastic mold or die's in such a way that there is no problem while ejecting the plastic component. So a minimum of 3 - 10 degrees of draft angle is given to every plastic component while designing.

close up

  

Final model. After designing the Class - B and Class - C surface I will now continue to the designing of Locators

So what are Locators?

Locators work as a 3 - 2 - 1 principle which is basically to fix a component to be machined or to be placed in an ideal position. There are a total of 12 degrees of freedom, 6 rotational and 6 translational.

In this, I need to fix any 11 degrees of freedom permanently and anyone to be clamped or fixed temporarily. In this scenario, Locators come into place. there are 4-way locators, 3-way locators, and more.

4 - way Locators and 2 - way locators

 

while making a locator the distance of all locators from the surface should be equal for all. The thickness for all should be around 1 mm. A minimum of .25 mm drafting is given to validate in draft analysis. And by placing these locators, we can arrest 11 degrees of freedom. 

Heat staking

This is also a fixing method of a plastic component to another dissimilar or similar surface or metal part. But in this process, both of them are joined together by thermal welding and can not be removed after that. A Boss or a stud is made on the plastic part, which is then protruded onto the opposite part and reformed after the locators fix the part temporarily and then thermal welded on the boss.

the distance from the surface should be less than the distance provided to the locators.

Draft analysis report on locators

 

on heat stake studs.

 fixing location on the surface