Week 8 - Challenge 5 - Core & Cavity Design

DRAFT ANALYSIS OF CORE & CAVITY OF SWITCH BEZEL

Objectives:

To create Parting surface & Parting line for this model

To design CORE and CAVITY of SWITCH BEZEL & add thickness to it.

To perform draft analysis on SWITCH BEZEL part model.

Explain importance of Draft in CORE & CAVITY.

Explain relation between Draft and Parting surface.

Steps to create of Parting Surface in SWITCH BEZEL model:

First, create a boundary line of Class-A surface using BOUNDARY option.

Now, extrapolate this Class-A surface using created boundary about 11 mm.

Trim this surface with Class-C surface of Switch Bezel.

Again, trim this surface with Class-B surface. Name this trim as “PARTING SURFACE WITH COMPONENT AREA”.

Now create Parting line with intersection with trim of A & C as well as Class-B surface and apply line type, colour and thickness.

Create SPLIT with Parting line & Class-B surface and name it as PARTING SURFACE.

Steps of creation of CORE BLOCK for SWITCH BEZEL:

First, create a sketch of rectangle surface in TOP PLANE. Remember to create rectangle inside this SWITCH BEZEL surface.

Extrude this sketch upto appropriate length in TOOLING AXIS direction.

Now, trim it with extrapolated Class-A surface. Fill the top surface of it and JOIN trim and this FILL to create CORE surface.

In last, use CLOSE SURFACE to create solid CORE BLOCK.

Steps of creation of CAVITY BLOCK for SWITCH BEZEL:

Use a sketch of rectangle surface created in early steps. Extrude this sketch upto appropriate length in TOOLING AXIS direction.

Now, trim it with extrapolated Class-A surface. Fill the bottom surface of it and JOIN trim and this FILL to create CAVITY surface.

In last, use CLOSE SURFACE to create solid CAVITY BLOCK.

Importance of Draft in CORE & CAVITY:

Some value of draft is applied on whichever material is used in mold making whether it is plastic, wood or steel.

Draft is required for construction of mold of complicated geometry for giving easiness in working of molding process.

In addition, draft is needed for easy removal of molded part as well as CORE and CAVITY part.

Relation between Draft and Parting surface:

Parting Surface: It is a surface at which Core & Cavity part is joined together with pressure during injection molding process.

Parting surface design directly affects ease of construction, operation of injection molding.

Draft incorporated in design helps easy removal and assembly process. Without some draft, mold of complex geometry cannot be easily designed as well as in working.

Steps to do draft analysis on SWITCH BEZEL model:

Go to insert > analysis > feature draft analysis or directly click on Feature draft analysis icon from menu.

First select compass option from pop-up menu to set axis system coincide with tooling axis.

Here change position of TOOLING AXIS by moving compass location and use lock option to fix it to give every surface a proper draft.

Surface model will turn into green colour surface, which shows that draft for model is in limit upto 3 degrees. Here I have given green colour for 3 degree draft, light blue for 0 and red colour for negative draft.

Run quick analysis on model and if any draft angle is more than limit, then one can apply new value of it in pop up box.

Full analysis shows different draft angles with different colours as shown in figure.

Here is an example of INVERT DRAFT DIRECTION analysis.

Below image shows the different views of draft analysis of SWITCH BEZEL model.

Here are snaps of feature tree of this SWITCH BEZEL model:

Conclusion:

I have learned about creation of Parting surface, Core & Cavity creation for them in given SWITCH BEZEL model in this challenge. Also, I understand the importance of draft in CORE & CAVITY.