16. Wildcard Week¶

This week is the one in which we get the opportunity to explore a digital fabrication process that incorporates computer-aided design and/or manufacturing processes not yet covered in previous weeks.

Eduardo Composites

16.1 The production of a 3D printed clay bowl¶

Since Eduardo Chamorro, our instructor, has vast knowledge on the use of 3D printers — and is constantly investigating new materials, procedures and possibilities within this field — our learning group was naturally drawn to take the opportunity to use this process and experiment bringing our own designs into production.

Eduardo pump

16.1.1 Design¶

Under the influence of Japanese pottery I decided to produce a simple bowl the size of my fist to be used for serving miso soups, steamed grains and vegetables.

By measuring my closed hand’s with and height I got a rough idea of the proportions needed and went ahead to the design software suggested for this purpose.

16.1.1.1 Software¶

All along we have been using software packages like Rhino, Autodesk Fusion 360, Blender and Grasshopper. However, for this week, the recommendation was to produce a shape on a simple 3D vase creator off of the internet.

week16.1

16.1.1.2 Workflow and .stl file ¶

Once the design is finished, it needs to be downloaded into the computer and opened with Rhino to prepare the geometry, components and printer configurations. The Grasshopper plug-in is used to embed these setting into the G-Code for the piece. Details like the selection of the specific settings like the size of the machine and the nozzle are taken into consideration; as well as the use of a cold extruder setting — for printing with clay.

The second section of the process in Grasshopper is related to slicing the piece in question. A good rule of thumb is to calculate between 30-70% of the nozzle — in this case a 3 mm nozzle would be paired with a 3.1 extrusion. The assembling requires for calculating jog speed (movement in the air) and extruder multiplier (rotations per distance).

In the following set of images is possible to see the workflow as well as the relevant setting for the procedure as they gather in detail all the necessary information to replicate [exactly] the piece: settings

16.1.2.1 Machinery¶

As mentioned above, the settings of the machine need to be adjusted to the specific job. In this case, the extrusion wait time should be 200 milliseconds to let the material set — as clay sticks to itself based on pressure, humidity and surface texture.

Other elements to consider carefully are: - Z Hop: it is the movement of the Z to another path - Z Base Offset: the thickness of the trays where the pieces are built on that has to be measured and taken to consideration

It is important to keep in mind that for this specific job/printer, a selenoid valve is used to regulate the cartridges of clay as well as an airbrush compressor.

16.1.3.1 Materials¶

Aside of the printer and computer, the following list of materials is called for the job: - Clay - Cartridges - 3mm Nozzle - Airbrush Compressor - MDF board to serve as base

16.1.3.2 Workflow and Production from .3dm to G-Code ¶

The Grasshopper file needs to be copied into Repetier and a new set of settings defined.

G-Code Repetier

Here is the image of the bowl being repositioned for printing in Rhino, as well as the addition of a Base Offset of 3 mm.

G-Code Repetier

Video ¶

In the image and video below is possible to see the transition from ‘bits to atoms’ taking place. Printer and computer need to be connected at all times during the printing process.

3D Ceramics