16. Molding and Casting


  • group assignment:
    • review the safety data sheets for each of your molding and casting materials, then make and compare test casts with each of them
  • individual assignment:
    • design a mold around the stock and tooling that you’ll be using, mill it (rough cut + (at least) three-axis finish cut), and use it to cast parts

This week we work on the most “nasty” and “mess” things of fabacademy: play with Chemical materials(to make mold and casting). But I love it so much :)

Designing mold

First I downloaded a STL file of Thor’s Hammer from Thingivers and Use Fusion360 to edit it:

Modify - Grid- Make it from Mesh to BRep to become a body to edit it.

Creat a flat between the model’s two surfaces and break it up then put it into the wax cuboid.

Here is the mold.


After the mold designing is finished and save it as a STL file then I can work on the setting of machining. We use SRM-20 to mill the wax. Here is the setting:

Roughing Setting:
Modeling Form (No margin);
Flat: “4mm Square”
Scan Lines: “X+Y”
Cutting Parameters:
* Feed rate: 900 mm/min
* Spindle: 9000 rpm;
* Cutting in Amount: 2.40 mm;
* Path interval: 3.00 mm;
* Finish margin: 0.20 mm;

Finishing Setting:
Modeling Form (No margin);
Flat: “2mm Square”
Scan Lines: “X+Y”
Cutting Parameters:
* Feed rate: 900 mm/min
* Spindle: 1000 rpm;
* Path interval: 0.5 mm;
* Finish margin: 0.00 mm;

All the setting looks good. Then I can start milling. First, we used this base to hold the wax to make sure it won’t move when milling:

Afer the Roughing and finishing, I got my mold’s mold(sounds confusing) for the first time. I can’t wait to use it to make a real mold.

Casting with the mold

I used Silicone Rubber, mixed them 1:1 to make my first mold. After a whole night waiting it finally shaped.

Then I deside to do 2 Extreme opposite thing ahaha~

Prepare for the test of ICE and FIRE

Then I decided to use some normal way to do my job for class.

I want to use resin and mix some Toning additives to make my hammer. I combined the resin 1:1 and mix in black and white color(hoping to have metal texture) for the head of hammer and mix in brown for the handle. But~~~

I messed up. The ratio of resin is wrong as you can see. But it still looks good for me.


This is very cool machin for this week to make a mold super quickly which is made by our instructor Saverio. It called vacuuformit. It use oven heating rod to soften the plastic and use vacuum cleaner to suck air and make it shape.

We clamping the plastic and put it on heating area, when it becomes for white to transparent and very soft. We put it onto the object that we want to use it for a mold shape. Then we turn on the vacuum cleaner then the color of plastic will become from transparent to white again.

When it is done, we turn off the vacuum cleaner and got the mold we want.

Oh~ by the way, it is Elfe’s cat. More details can seen from her website.

More funs

I came up with an interesting idea: to put something into the object, like an amber. So I soldered a really small circuit and put it into the resin for it is transparent to see the object inside of it.

Actually because the front side has a lot of bubbles, so I perfer the back side. And the most interseting thing is that: you can press the button to light on the LED ahaha~~

Cats! More cats! A lot of cats this week!

Play with different material that we have

All the materials that we used for this week.

  • A: drystone
  • B: OOMOO25 silicone rubber (exceeded shelf life)
  • C: silicone rubber paste
  • D: extra soft silicon rubber, 10 shore hardness, skin color, especially suitable to reproduce human skin in special effects


This is STL file for the wex mould: S Thor’s hammer.stl

It was really a colorful week!