P2_Casting2_Cast Lego

Karina Silvester

klsilves@mit.edu

1.18.2011

For this project I wanted to create a 3 modified lego pieces that link into each other.  By Casting and molding these pieces, many could be produced to create a multitude of creations.

I began by milling the 2 halves into 2″ foam.

Results from the Techno CNC mill.

Detail of the step over problem from resetting the origin.

Solution to create new registration points and semi-sphere lego links.  I used a 1/2″ dowel and sanded the end to round it off.  Holes were drilled in the appropriate places and the dowels were inserted.

Gesso was needed to fill in the new gaps.

Here is an image after two coats of gesso.

Then the foam was then lubricated with a thin coat of soap.  To create a negative mold, Oomoo 25 Silicon Rubber was poured over the soap in the foam.  When I tried to remove it after the first coat, I could feel the fragility and fear tear the thin regions.  Thus, I applied a second coat to build up the strength.

These Silicon molds were then used to cast plastic into them.  Since they are flexible, they can be used over and over again to produce many identical pieces.  In the future, I would sand and clean up the original foam mold much more to create cleaner edges.