• Contant
  • Project
  • Assigments
  • About me
  • HOME

Fablab Seoul

JIN`s Fab Academy 2018:
How to make almost everything


week10: Modlding 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 `Task2 ` `Molding star 16 Fast`

1. learing eco-soap design

I thought what I would do in Molding and casting. So I tried to relate to the final project but wanted to do something more meaningful than that.
So I came to think about the environment. I will make soap to recycle the waste cooking oil that is discarded.
So I created a design that combines a bud with a Fab symbol of the environment that means green.


We must always think of nature.

I modeled it with a Fab symbol and put it on a bud.

Fusion360 brings the image file to Insert. Then I move it to where I want to design.

And I painted slowly along the image with the spline. And I completed it on one side.

I finished the design. I made the design to feel eco.

-Modling design-

I am sizing the Milling wax to work to make a modling design. The size of the wax is 160 * 100 * 38 mm.
I designed it to suit it. And since I make soap, one side may be flat.
So I did not make air holes and silicon inlets separately.

Fabmoudles-rough cut-

I set up to complete the design and make a 3D cut in FabModules.
1. Select the mesh in the input format.
2. Load the STL file.
3. Modify the unit to mm 25.4.
4. Set the xyz angle (you should see the top of the screen, it's easy to think of it as the z-axis).
5. Set the dpi. Usually 1000 (dpi indicates quality)
6. Click calculate height map to calculate. (The color of the image should change on the screen.)
7. Then set the output format by pressing (I set it to Roland mill).
8. Set process wax rough cut (1/8).
9. Set the output machine. (SRM-20) (speed is cut to 20 if the wax is smooth).
10. Set xyz home to zero.
11. Set zjog (I set it to 10).
12. Set the tool diameter. (I set it to 3 because I cut it to flat 3mm.)
13. Press calculate to wait for the file to be converted. (It usually takes about 30 minutes.)

Fabmoudles-finish cut-

1 to 7 are the same. 8. set process wax finish cut(1/8) 9 to 11 are the same. 12. Check endmill size for finish cut 13. Finally, set the endmill to cut with flat or ball

-My mistake-

Here I made a lot of mistakes.
I have not changed the unit at first, so I have not been able to convert the file.
And finally, it takes a lot of time to calculate the file.
So it may take longer if your computer is slow or the Internet is slow. Please note!

I modeled it to fit the wax size and erased the unwanted parts.

If the unit is mm, you should change it to 25.4. You can see the layer of file conversion on the top left.

Enter the set value and press Calculate. The calculation takes about 30 minutes to 1 hour.

For rough cuts, a diameter of 3 mm was used. For the finish cut, ball endmill was used and the diameter was 1mm.

2.How to change SRM-20 collets and cut the wax-

I first tried to change the collets on the SRM-20. This is because you must use a smaller endmill than the PCB cut.
The way to change collets is the same as Shopbot CNC Louter. You can use two wrenches.
And when you cut the wax, you have to check the size by air cut. Without aircut, cutting can fail.

-My mistake-

I did an aircut, but in Fusion360 the wax size was tight and I was not on the wall.
In FUsion360, it is better to design the wax slightly smaller.
And because the diameter of the endmill is small, it is easy to break.
So when you hold the endmill in collets, you have to hold it deeply. Otherwise it breaks.
I broke the endmill. Then the finish cut failed.


It is an endmill for the use of several types of collets and rough cuts. Information can be found in the endmill box.

Two wrenches are required to replace the Rollet SRM-20 collet.

Replace the collet in the same way as the CNC Louter. I cut the surface and checked the size.


The finish cut endmill was ball cut. It is information about Wax. I used blue wax.

It's a rough cut.

I broke the endmill while finishing the cut.

I made two mistakes. 1. The wall on the top was cut off because it was not well sized. 2. Endmill broke and failed the finish cut

I fixed it by adding acrylic on top of the wax.
Rough Cut the Wax

3. learning to Molding and casting


We used `Smooth-on` `Mold star 16Fast` as a molding material.
Mold star 16Fast has low viscosity and fast curing speed. Excellent heat resistance (232ºC).
-A:B=1:1 by volume
-Working time: 6 minutes
-Curing time: 30 minutes
-Hardness: Shore 16A
-color: Blue-Green
`click the Safety data sheet`

We used `Task 2` as a casting material.
Task 2 has excellent physical properties and high tensile and flexural strength.
-1(A):1(B) by volume
-but 1(A):1.15(B) by Weight
-Working time: 7 minutes
-Curing time: 60 minutes
-Hardness: Shore 80D
-color: White
`click the Safety data sheet`
You must be familiar with the safety data sheet.
Because silicon is a chemical product, it is harmful to our body.
If this chemical touches my body, I can get a skin disease. And if you keep smelling this material, you can get dizzy and bad for breathing.
So be sure to wear a mask and gloves, and be careful not to get the silicone on your body.

We wore a mask and safety gloves.
Work must be carried out with safety attention.

-Molding and casting-


1. Spray oil on the wax to make the moldings. Spread throughout,
2. Place the cup on the scale and insert part A and part B.
3. Mix. (Note time.)
4. Pour into the wax. (Put it in a little place where there is no air.)
5. Wait.


I got moliding with the help of a teammate. I mixed it for two minutes.

I dropped the material from the high place to remove the air. You should finish your work in six minutes.

Smooth on is the material. We have completed the mold.

I used `Mold Star 16Fast` to make the mold. Be sure to check the safety data sheet before using it.

I used `Task 2` to do the casting. Check the safety data sheet for each material.

Task 2 hardens in 7 minutes. Because it is harder than mold star, you have to move quickly.

-Download File-

mold design
mold rml
moldstar16fast
Task2