How to make (almost) anything

by Gabriella Gardosi (Gaia Gaoi)


Composites

This week I will create something really strong from a polystyrene mold using fibre and resin.

Part One 2D to 3D- Design of the Mold
Part Two Using Rhino CAM
Part Three CNC Milling of Polystyrene Mold
Part Four The Composite: Fibre and Resin
Part Five The Files

2D to 3D Design

This week my inspiration was Henri Matisse. I took one of his cut out forms converted it to an indexed image in Gimp, vectorized it in Inkscape and sculpted it into a 3D model using Blender.
A purely open source program workflow!



Creating a flat bottom by selecting an edge all around the form and deleting it. Then extracting the remaining shape to zero.

Using Rhino CAM

CNC simulation using RhinoCam

I measured my polystyrene block and created a block in RhinoCam. I selected the block as my Stock Material using the option Stock from selection . Then I deleted the block.



Selecting drive containment which contains shape to be molded.

CNC will mill the shape in two stages:

Settings for Horizontal Roughing for polystyrene using 12mm mill
50% step over for Horizontal Roughing
Settings for Parallel Finishing using a 6mm mill with a 25% step over

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Posting both processes to generate the g-code and saving the files to use on CNC Mach-3

CNC Milling of Polystyrene

Initially I got the X and Y axis mixed up on the machine. Thankfully milling in the air first meant the problem could be identified.

Using this 12mm mill for Roughing and a 6mm mill for Finishing

Between the Horizotal Roughing and Parallel Finishing Stages





The Composite: Fibre and Resin

On recommendation by Anastasia from the Fab Lab Barcelona I used Lycra as my fibre. The resin was Epoxy Resin.

2 part Epoxy Resin to 1 part Hardener ( Supersap brand)











Into the Vacuum Machine for 6 hours...




Out of the Vacuum Machine





















The finished piece! I am very pleased I managed to get my mold out intact- cling film works like a dream. The vacuum had some trouble getting inside some of the curves which could be improved by vacuuming with the negative of the mold on top

The CAD file of the Matisse form can be downloaded here