Creating molds from 3D Printing?

[3dkarma]

sorry. i didnt understand how the indirect method with wax or pla works.

Ah, OK. There's a good writeup (with lots of pictures and video) of lost PLA casting here: http://3dtopo.com/lostPLA/

Edit: Comprehensive writeup of lost ABS casting here: http://jason-webb.info/2012/11/lost-...minum-casting/

[navkram]

Ah, OK. There's a good writeup (with lots of pictures and video) of lost PLA casting here: http://3dtopo.com/lostPLA/

Edit: Comprehensive writeup of lost ABS casting here: http://jason-webb.info/2012/11/lost-...minum-casting/

Thank you for these links great information in both of them.

[python]

Thanks !

I wonder if this can also be done with uv-sensitive resin prints.

[Larry]

Has anybody ever experimented with creating molds via 3D Printing and then pouring liquids into the mold to create the object? Kind of the inverse of what we traditionally think of when 3DP'ing.

This is actually what the European Space observatory is doing with 3D printing. They make molds of parts for their telescopes with 3D printers and then pour aluminum into those molds.

[mechadense]

I tried printing flexible PLA as a mold for PU. I used silicon spray as release agent. => The mold got destroyed after only one use.
My grey soft PLA behaved like chewing gum :S very little shape memory.

For small quick and cheap stuff I now use ogoo (acetic silicone + corn starch). It sticks on PLA while wet and goes off easily when dry - just perfect.
I used wax based release agent to quickly make around a dozen PU copies from a single mold from a specific PLA part (PLA positive -> ogoo negative -> PU positive)
An other release agent might be better (less viscous)

[LambdaFF]

There is a quite simple technic that you can use. With electro plating you can create a metallic layer of zinc or copper or nickel on you part. If you make the deposition thick enough it can make a mold. You will need to put some conductive paint on your plastic part first as it is not conductive.
Conductive paint : ~14€/400mL.
Copper Sulfate : ~20€/1kg
Car battery, a pair of crocodile pincers.
And then you remove the plastic by heating. It's easier if it is wax, but perhaps it would work as well if you do it with a soluble material like the ones for support.
However, it only works if the end material is supple enough to be extracted. Otherwise you need to cut the design to make separate mold parts.
CATIA has excellent molding design tools.

On a different note, for the release agent. If your part is big enough, most composite manufacturers cover their big (read costly) molds with teflon adhesive or a teflon coating. I never saw it in Europe but in China you can find it in spray cans.