Molding and Casting | Week 10
Week Content
Oval Shape Paper Weight
In this week I was trying to make mold in which any access left material can be used to cast a Paper Weight and left over material get used.
Paper Weight is Oval Shaped Design which can be used for playing with by spinning it on table.
Process
CAD Design
Creating a 3D .stl File to Mill using Roland MX 20
- By using Rhino we can create a 3D model of Oval shape
- I have designed according to wall required for molding casting
- Creating 2 rectangle of desired wall thickness by Rectangle and Offset commands
- Then create Elipisoid and trimming it we can get desired design
- export that file to .stl format.
![](images/week12/w12screen1.png)
![](images/week12/w12screen2.png)
![](images/week12/w12screen3.png)
![](images/week12/w12screen4.png)
![](images/week12/w12screen5.png)
Milling by MOdela MX 20
I have used 90 mm X 70 mm X 40 mm Wax Block for Milling
- Using Double side tape I placed Block on Milling bed, So it get fixed and don't move while milling process
- In Ubuntu > Open Terminal > enter command sudo fab >password fab a window will open
- select mesh .stl as input and Modella MX 20 as out put
- New window will have option of loading .stl file after loading click on make .PNG
- select tool Inches 1/8 Rough for rough cut going to use finish cut in next process
- Click on make path it will show a tool path generated
- then set X axis - Y axis ( Note this you need same cordinated to start in next Finish cut )
- Make RML
- Send and Start Milling.
- Observe Path if you find something wrong stop machine.
- After process you need to change tool to finish cut
- Again process will happen with ball nose milling bit to have finishing surface.
![](images/week12/w12-milling-1.png)
![](images/week12/w12-milling-2.png)
![](images/week12/w12-milling-3.png)
![](images/week12/w12-milling-4.png)
![](images/week12/w12-milling-5.png)
![](images/week12/roughcut2.jpg)
![](images/week12/roughcutfinal.jpg)
Preparing Mold for casting
- Check for proper level
- I have added 4 mm of cover to raise level
- By using paper-tape and CANDY STICK
- You can use sand or any filling material for measuring exact volume to be filled
Rubber
- Two Solution provided PART A & PART B
- For Rubber we need to take EQUAL proportion
- By using 2 plastic glass and then in 1 glass we can mix it.
![](images/week12/moldpreparing.jpeg)
![](images/week12/moldborder.jpeg)
![](images/week12/rubbercasting.jpeg)
![](images/week12/mixedrubber.jpeg)
![](images/week12/pouring.jpeg)
![](images/week12/setting_of_rubber.jpeg)
![](images/week12/rubber mold.png)
Now using Plastic we will cast Positive Final Output.
![](images/week12/plastic.jpeg)
![](images/week12/plasticmix.jpeg)
![](images/week12/pouring_plastic.png)
Output
![](images/week12/output.jpg)
Wax Mold, Negative Rubber Mold, And Positive Casted Plastic
Some Quick Points
- I made a mistake by creating same surface level of Oval and wall So I needed to have little more height of walls.
- Later after Casting I found 30% of Molding Rubber getting waste ( We can use sand for measuring exact volume and then divide according to it)
- Check proposition is in Volume or weight because density of both Part A and Part B is different
- I faced error while loading stl file Right process is Load stl > click Make PNG > Select tool.
- Wrong Process : Load stl > Select Tool > Make PNG ( Laptop will Hang in my case )