Lecture Notes
I’ve updated Week12’s lecture notes in my gitbook .
Assignment
design a 3D mold, machine it, and cast parts from it
Design
I’d like to make some tetris parts :)
I use Fusion 360 to design the mold:
Set parameter:
Creat sketch:
Extrude the shape:
I can make this positive shape using milling machine. Then put it in a wooden frame and pour molding material onto it to form the mold. The bule part represents the wax and brown part represents the wooden frame.
Then I export the component to stl file which you can download here.
Machine it
We use MODELA Player4 to open stl file. In our lab we have modelling wax, so I choose the materials to be milled:
Settings:
Choose new process - surfacing
Choose tool - 3mm Square
Choose new process - Roughing
We use SRM-20 to mill. Adjust the original point of the machine like the PCB routine. Click Output and the computer will start to calculate and mill.
After machinaing the shape, prepare the solicone and the poured mold in a wooden frame like this.
Then casting from the mold.
The result was not so good due to the mold size. I should make some perfections next time.
First trial
I use my 3D Elizabeth for mold:
First, print it out with a 3D printer:
Then prepare some materials for mold building:
- PMC-121/30 URETHANE MOLD COMPOUND (PART A)
- PMC-121/30 WET RUBBER MOLD COMPOUND (PART B)
- A plastic cup
- Gloves
- Stir bars
- Goggles
Mix the compounds with a propotion of 1:1:
Stir the compounds fully:
Put my pink 3D Elizabeth into the cup:
And fix the position:
This material will cure overnight(16h) to a flexible 30A dorometer rubber suitable for making molds.
My mold came out!
Next step, use drystone to make another Elizabeth:
Mixed drystone and water with a portion of 47:100:
Then poured into my mold:
And a new gypsum Elizabeth came out:
