The process outlines the stages and tools utilised to produce a voronoi resin screen. The screen itself exploits the material qualities of the resin and digital fabrication technologies to produce a final screen that has varying light qualities. The qualities produced by the voronoi screen are only possible by the implementation of digital design and fabrication tools. This yields new materials with multiple performance qualities.
MDF – dimensions depend on the size of the voronoi screen
Polyester resin – amount depends on the size of the screen
3 axis CNC
Rhino, this is a computer modelling software, a trail version can be downloaded at http://download.rhino3d.com/rhino/4.0/evaluation/download/
Grasshopper – this is a free parametric modelling plug-in for rhino this can be downloaded at http://download.rhino3d.com/Grasshopper/1.0/wip/download/
The initial step is to generate a 3d model in rhino using the parametric plug-in grasshopper. Open rhino and in the command line type grasshopper and press enter. In grasshopper produce the definition outlined in the jpeg or the definition to produce the voronoi screen can also be downloaded at http://www.grasshopper3d.com/forum/topics/voronoi-cell-issue-fillet-and. The benefits of using the grasshopper tools are the multiple parameters produce varying results with no extra work. The definition is then baked and this produces a model in rhino that can be further manipulated in rhino.
When the definition is ‘baked’ it produces a screen with cell depths that only have the same depth. In order to produce varying depths multiple planes are produced at varying heights between the screen depths. The planes are the Boolean intersected with the voronoi cells.
Save the final rhino model as a 3ds file.
Get a piece of wood that is as close to the dimensions of the 3d model as possible, it should be close to the 3d model dimensions as the cnc machine is a reductive process and this results in waste materials.
The 3ds file can then be loaded into the interface of the cnc machines software, stages are then carried out in the software for the cnc machine to physically produce the 3d voronoi model. Note a 3 axis cnc machine can only move a parallel directions with regards to the x,y and z axis, it cannot machine a 3d from that goes back on itself.
This screen used a 6 mm ball nose drill bit, this produces a very fine finish to the material.
Once the cnc machine has finished producing the 3d form it then needs to be vacuum formed, this produces a negative to be cast into.
Now the voronoi screen has been vacuum formed the negative can now be cast into producing a positive final resin cast.
This voronoi screen used 200ml of polyester resin which requires 50 drops of a resin catalyst to set the resin. This ratio should be further detailed in any resin casting kit found at any good art store. The polyester resin is opaque, a 10ml of a glass lacuer colour agent was added to produce an orange colour, various glass lacuer colours can be used. Depending on the amount of resin used effects the setting time of the resin, in this case it took 40mins to completely set. Note the resin gets hot when setting so cast onto a heat resistant surface as it can deform thin plastics. Resin casting should also be carried out in a very well ventilated space.
Once the cast is set the final screen can be taken out of the mould produce a final voronoi screen that is robust and has various light qualities.