12. Moulding and Casting¶

Learning outcomes¶

Design appropriate objects within the limitations of at least 3-axis machining
Demonstrate workflows used in mold design, construction and casting

Objectives¶

Link to the group assignment page and reflect on your individual page what you have learned
Review the safety data sheets for each of your molding and casting materials,then made and compared test casts with each of them
Document how you designed your 3D mold and created your rough and finish toolpaths for machining, including machine settings
Shown how you made your mold and cast the parts
Described problems and how you fixed them
Included your design files and ‘hero shot’ of the mold and the final object

Link to the group assignment page¶

https://fabacademy.org/2021/labs/vancouver/students/christopher-proute/group/week10/

Creating the desion using Fusion360¶

I decided to create a 2 part mold for the casting of a pawm piece.

For this weeks assignment i decided to draw a pawn piece using fusion360.

I reviewed the dimensions of a pawn piece and decided to use a canvas for measurements from the following website.

https://grabcad.com/library/pawn-chess-coin-1

The first thing i did was created a sketch outline of the object.

I then used the revolve command which created a 3D solid by sweeping the object around an axis.

A 3D representation of the pawn piece was created as shown in the image below.

I then created another sketch of a rectangle approximately 2in x 3in.

I then used the extrude command to create a height of 1.5in.

I used the offset command to create another sketch of a rectangle on top of the solid created.I then used the extrude command again to create an inner cut out of the block created.

I then aligned the pawn piece and using the move/copy command i placed the pawn piece in the center of the rectangle

I then grouped the two objects together as one solid object.

I then created some studs and holes o.5cm in height and depth on the inner surface of the material so that when the two parts are put in place the would lock together.

I then set the stock dimensions:

stock width (X) > 75mm
stock depth (Y) > 50mm
stock height (Z) > 38mm

Generating the toolpath for milling¶

I went to the 3D banner and selected 3D pocket clearing.

Next I selected the tool for milling 1/8” inch flat end mill.

Then I disabled the coolant because the machine i will be using doesnt have any.

Changing the cutting feedrate to determine how fast you want the tool to go on the surface while cutting(leave as default)

Adjusting the lead in and lead out feedrate to determine how fast the tool enters and leaves the material(adjusted both to 700mm/min)

Next I selected the proper geometry of the model I want to carve.

Then I double checked clearence height for the model(leave as default)

Next i went to the passes tab and unchecked the stock to leave box and checked the multiple depths box and changed the maximun roughing stepdown to 0.5mm

I then navigated to the linking(how the tool operates between different g-codes) tab and reviewed the ramp type to determine how the tool will go down into the stock material.

I clicked OK when I was finished and fusion360 calculateed the toolpath.

I the proceeded to create a simulation of the milling toolpath to see if the material was being removed correctly and what changes need to be made for correct operation.

The tools used for milling was the 1/8 flat end mill for the roughing operation and the 1/8 ball end mill for the smoothing operation.