Assignment 12: Molding and Casting

I selected icosahedron as the object. I found a nice one in Thingiverse: http://www.thingiverse.com/thing:37797/#files.

I imported the object to 123D Design. And made it solid for splitting.


The I constructed the bottom and walls and filling pipe to the mold.


I scaled the design to half and exported it as stl-file.

Then I opened Roland Modela Player 4 and opened the design:


I set  set model origin:

and zeroed the margins:

selected a new process for roughing:


with a 3,18 mm flat milling tool:

with default tool path:

and cutting parameters: I changed to speed to 30 mm/sec and path interval to 1.5 mm, which equals ~47 % overlap.

The tool path looks like this:

and the simulated result as this:



The finishing:





Milling:


Wax Mold:


Rubber casting:

The liquid rubber is OOMOO®25 Tin cure silicone rubber, which has a 15 min pot life and 75 min cure time. The two components have one-to-one by volume mix ratio, and it does not need vacuum degassing.



Rubber mold filled:


Rubber mold:


Plastic casting:

The liquid plastic is Smooth-Cast®310. Also its two components are mixed one-to-one by volume, and it requires no vacuum degassing. It has a pot life of 15-20 min. and cure time of 3-4 hours.

The rubber mold halves are exactly the same size, so they just have to be aligned. With a clamp and two pieces of plywood I carefully clamped the molds together:


Plastic casted:



Mold opened:


The part came out fine with a soft touch of knife and a file:


Files:
123DDesignFile
STL

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