Week 9 - Attachment Feature Creation - Challenge 2

AIM:

To create the screw boss and Dog House for the Centre console coin holder considering the design rules and perform the draft analysis.

Given details:

General Guidelines for Bosses:

• 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.

"C" is where the doghouse contacts the backside of the surface.

• 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

PROCEDURE:

SCREW BOSS:

First create the two circles by using sketch.

The inner circle diameter is 5.2mm and the outer circle diameter is 8.2mm as per the design criteria.Thickness of the screw boss should not be greater than the 40% of the boss.

Than draw the two ribs by using the sketch,by following the rib design rules.

Than give the draft angle as per the design rule the value is 0.5 degree.

And give the fillet value is 0.25mm as per design rule.

Copy the screw boss with all childrens and paste it.Than translate the screw boss by giving the x.y,z coordinate.

DOG HOUSE:

Dog house is an engineering feature used in plastic trim design. They are used as supporting features. Sometimes other engineering features like snaps, locators etc. are mounted on them to increase their strength.

For dog house first extract the base sufcace and create the point and insert the plane with the reference of point.Then create the sketch of rectangle.

Than by using swep command to swep the sketch with angle of 1.5 degree.

Offset the base extract surface about 20mm,than trim it with the swep surface.

After that thicken the dog house by 2mm.

To get the perfect finish shpae extract the inner surface and offset it 21.5mm,and split it with the thicken body.

Than give the draft angle as per design rule 0.5 degree at inner face.

Than give the fillet at all the inner edge as per rule the radius is 1mm.

The height of the dog house is given as 4mm where as given design parameters it was indicate between 3-6mm.

To achieve the c value in the dog house as mention in the question,made an extract on the inner face of the dog house and made an offset of 1mm(0.4*2.5=1mm).

Than trim the required surfaces by using trim option.

and the final output is getting the shape like this.

split the dog house with the last output section.

Than the draft is given at the inner side surface of the split body.

Than give the fillet value of 0.5 at the drafted edges.

Draft analysis:

Dog house having two tolling axis one is main tooling axis and another one is side core tooling axis.

To perform two draft analysis to clear the tooling.

The Draft Analysis allows the user to easily analyze a part for proper draft angle. A Draft Angle describes the amount of taper for molded or cast parts.

Draft analysis for side core axis

Than finally translate the screw boss in to the top of the dog house.tHis is the final required output

Views:

Front veiw:

Side view:

Top view:

Isometric view:

Tree structure:

Result:

The creation of the screw boss and Dog House for the Centre console coin holder considering the design rules and perfomed the draft analysis sucessfully by using catia software.