How to Use MDX-20 for Making Molds

Hi everyone,

This is a compilation of basic tips and instructions on how to use MDX-20. Although it is an old deprecated machine but it still has many capabilities one of which is making molds.

How does molding machine work?
Molding machines are at heart considered milling machines (similar to CNC machines) that can do cutting & engraving. What makes the MDX-20 special is that its height in the working area is relatively much more than that of a CNC machine. Meaning that you can make deep engraving/milling on your work piece. Milling machines use variety of materials including but not limited to: wax, wood, foam, acrylic, poly acetate, ABS & PCB. The milling machine uses a thin drill bit to engrave and cut through different materials.

Making the mill is the first step of this process. After milling a piece of material, we will then fill it up with liquid silicon to create the mold. Once dry and solid we can pour in the final casting using materials such as liquid plastic.

We gotta start somewhere right? :P

Use double sided tape to stick the wax block on build plate

A) Usually we start by roughing out the general shape of our 3D Model

B) Bits explanation:

1. Bits come in different sizes (1/8, 1/16, 1/32, 3/32, 1/64….etc.)
2. 1/8 is generally used in the roughing & surfacing processes.
3. Depending on the detail level you wish for, in the finishing process we will go with 1/16 or 1/32 bit size.
4. Some bits have “BN” which indicates it has a ball tip. Such bits are good for making smooth curves. Bits which don’t have “BN” written on the stamp are square bits which are good to make 90 degree angles (for example to make cube model).

C) Use the provided Allen Key to replace the current bit to 1/8 bit size

• Check the size, modeling area, bit sizes & other settings

• Wait for the MDX-20 to finish making the model

Use Liquid Silicon to make your mold (we use OOMOO, other brands have different curing times)

1. Combine 50/50 ratio of both bottles and stir for about 5 minutes
2. Pour in the liquid in the milled cavity
3. Leave it to dry out for at least 12 hours (preferably 24 hours)
4. Once dry, take it out gently out of the mill.

Use Liquid Plastic to get your creation!

1. Spray Mold Release evenly over the milled area. NOTE: do not over-spray the area!
2. Combine 50/50 ratio of both bottles and stir for about 2 minutes
3. Pour in the liquid slowly to make sure no bubbles are left inside.
4. Wait for about 10~15 minutes until the liquid becomes solid
5. You model is Ready!