3D printing moulds for investment casting

Having a 3D Printer that can create plastic prototypes is one thing, but having the ability to have printed plastic moulds that are cast into metal, is a huge leap forward for low volume runs.

The process involves the following:

  • 3D Printing your part using a material based from Corn Starch called Poly(lactic acid) PLA. (You can’t use ABS as it is toxic when burnt out)
  • Contact your local foundry and ask if they can do investment casting and show them this blog post.
  • Send the part to the foundry
  • They attach the part to a pattern tree with other parts.
  • The 3D printed part is dipped into a tank of ceramic slurry and left to dry.
  • It is put into a furnace to 150 degrees, so the PLA becomes a liquid is then poured out of the ceramic mould. What is left is a hollow mould of your printed part.
  • Molten metal is poured into the mould and left to cool.
  • The ceramic mould is cracked away and the casting is removed.
  • The part is then ground or sand blasted to finish it.

Casting from 3D printed parts

Using 3D printers offers a great alternative to the traditional methods of casting as it offers a faster, more affordable, and less labour intensive casting processes.

3D printed moulds are ideal for the production of small product runs where the cost of traditional tooling would be prohibitive.

By printing your mould, it is a great replacement for wax pattern making – saving weeks off the traditional process for prototyping metal parts.

Picture: From Left to right – Stainless steel, PLA and ABS parts.