Week 9 - Attachment Feature Creation - Challenge 2

AIM :- To create a screw boss and dog house on a coin holder and perform draft analysis

INTRODUCTION :-

SCREW BOSS- Boss features are commonly found in injection molding designs. They are used to aid in the assembly of molded parts by providing a channel for a screw.

DOG HOUSE- Dog house is an engineering feature used in plastic trim design. Dog houses are used as supporting feature. Sometimes other engineering features like snaps; locators etc. are mounded on them to increase their strength.

Design Rules for Screw 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.

Design Rules for Dog Houses:

• "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:

Extract the surface and create the sketch of the boss

create a body ,rib and give draft 0.5degree.

DOG HOUSE:-

Extract the surface give thickness and create the sketch of the Dog house and sweep with draft of 0.5 degree.

DRAFT ANALYSIS OF SCREW BOSS AND DOG HOUSE :-

CONCLUSION :-

The Screw boss and dog house on a coin holder and perform draft analysis has been successfully created, considering the design rules as mentioned in the given data.