Challenge

Week 9 - Attachment Feature Creation - Challenge 2

DDiwakar Rajan16 Mar 2023

ATTATCHMENT FEATURE CREATION 2

OBJECTIVE:

To create the Door Trim Plastic Component from the given Class A Surface & then create two dog houses as attachment features for it while following the given Design Guidelines.

DOG HOUSE

Dog house is an engineering feature used in plastic design. Dog houses are used as support feature. Sometimes other engineering features like snaps, locators, screw bosses are mounted on them to increase their strength.

Dog houses are subjected to draft analysis to prevent breakage of the component during ejection from the mould cavity. Dog house and oher engineering components are built on the B-surface.

CLASS A SURFACE:

Class-A surface means visible surface. It gives the aesthetic of the component which is created by the styling team and gives to the part design engineer to create the part with all engineering aspects.

Given CLASS-A surface

TOOLING AXIS:

Created the plane regarding the XY plane
Intersect the created plane with respect to the class A surface.
Hide the class A surface and create point to point lines on the suspected drafts.
Create bisecting line with the two lines and point to create a tooling axis.
Bisecting lines were used to get the exact medium from the two sides so that maximum positive draft angle can be achieved.
The tooling axis is created for the component by bisecting two axis from x and y planes.

CLASS-B surface creation

Class-B surface means thickness of a part it is not visible and is inside part. In other words, Class-B surface is a surface below a certain thickness from the class-A surface. This is the surface that contains engineering aspects of a model.

Create offset surface of CLASS-A about 2.5mm inward direction.
Check for the discontinuity and rework on the offset surface using extract, multi-extract, multi sections surface.

CLASS 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 draft direction (TOOLING AXIS) 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 check whether the final body is closed by using boundary command.

FINAL CLOSED SURFACE:

DOG HOUSE Creation

Dog houses are designed to avoid SINK MARK created on the CLASS-A surface by screw bosses and to solve the length issues when giving screw bosses which need to be assembled to other components.
It is also useful when perpendicular screw bosses are required on the part to the tooling direction.

Make a rectangle to enclose the screw boss in it but make sure it is open from one side.

Sweep it with tooling axis as the pulling direction and give a minimum draft of 3 deg inwards.

Enclose it from the top by using the off-set of extract of the base of class-A surface. The offset distance determines the height of the dog house, so give it according to the design rules.
Use the same extract of class-A, and offset it at the height of 3mm-6mm. 8. Extract the inside faces of the dog house and offset it outwards at 0.4't and trim them togather.
Go to the part design and split it with the model
After that we will fillet the entire model of the dog house and add it to the main body