Week 9 - Attachment Feature Creation - Challenge 2
WEEK 9 CHALLENGE 2-ATTACHMENT FEATURE SCREW BOSS AND DOG HOUSE
AIM :
To create the attachment features screw boss and dog house on the coin holder using the given design rules.
PROCEDURE :
DRAFT ANALYSIS :
No parts can be ejected from the tool if it is having a straight 90 degree profile from its base surface. A small draft angle is provided to each and every area of the component in order to get an easy removal of the component from the tool. Draft analysis technique is used to analyze whether our part model created in cad is manufacturable based on the draft condition applied.
Here the part should get easily removed from the panel dies (in case of Sheet metal part) or Mold (in case of plastic). Here we are providing a direction in which components should eject inorder to get an easy removal of components from the tool. In other words it also lets us know whether the model is having a draft angle and
how much is the draft angle from the tool direction.
TOOLING AXIS :
The tool axis is the parameter which decides whether the tool enters into mould or not as as it denotes the draft clearance angle where a moulded part is easily removed from the mould.
PROCEDURE FOR CREATING TOOL AXIS :
- Firstly we will be given with a class A surface which is looked as a asthetic and a smooth finish which is created with a Alias software workbench which is also known as a free imagination surface.
- For that class A surface we need to check a boundaries first to check any unattached faces is present in that surface.
- The below is the image of a class A surface which is given as a input.
- So next we need to take a dummy tool axis to get a real tool axis.
- Next we take inclined lines to the surfaces we assume that draft is required.
- Then we intersect the both the lines and the bisecting line will be the tooling axis.
- Below is the image of the tooling axis.
So in this model the main tooling axis is taken in the direction normal to base as there is a shell in that direction and that shell is cleared with draft in that particular direction.
The yellow dotted line shown above is the main tooling axis for this model.
DRAFT ANALYSIS PROCEDURE :
Here in the above image the green shows the draft clear area and the blue area shos the zero draft angle because this surface is parallel to the tooling axis and the draft can be created on this surface by the class A surface designer.
So now here after the solid model is created we have to design screw boss and dog house on the surface where it is preferred according to the design rules.
The solid part of class C is given below :
DESIGN OF SCREW BOSS AND DOG HOUSE :
SCREW BOSS :
- Draft - 0.5 degrees on walls of boss
- Thickness - Typically 40%* of the nominal wall at the base.
- Height to Diameter Ratio - 3:1
- Radii - 0.25mm maximum radii.
First we have to choose the B-side area to design the screw boss where ever it is needed with the assigned design rules for screw boss.
Geometric sketch :
This is the sketch for the hole of screw boss :
The sketch for the supporting ribs for the screw boss :
The screw boss is shown in the below :
DOG HOUSE DESIGN :
-
Doghouse wall thickness at the intersection of the part wall ( C ) should be 40% or less than the main wall stock ( T ).
-
Height of ( B ) should be between 3.0 – 6.0 mm
Geometric sketch :
So to create a dog house we need to perform multiple operations like extrude, offset, trim operations and thickening method to create the dog house.
Below is the image of the dog house creation :
So after creating the dog house we need to translate the screw boss to the top of the dog house and attach to the dog house.
DIFFERENT VIEWS :
FRONT VIEW :
TOP VIEW :
ISOMETRIC VIEW :
GOOGLE DRIVE LINK :