Open source Hardware

OBJECTIVE
In this assignment, I will propose to hack the Wax Extruder, used in the FabAcademy, to print the Bio-Plastic.

Matter to 3D print Bio-plastic
Printing bioplastic allows creating a variety of composites, without relying on the special formulations that are required with other traditional 3D printing technologies such as SLS, SLA or FDM.

The customized material allows the designer to control the property, shape, and behaviors of the outcome. Moreover,  controlling the composition is possible to design intelligent material, like hydrogel, photomechanical, bacteria-based and others.

ANALYZE THE MATERIAL AND UNDERSTAND THE NEEDS.
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In order to understand how to hack the tool is important to understand the property of the material.
I start to make several tests with the Bio-plastic using a syringe. During the 3d print simulation, I tested:

  • Pouring temperature
  • Extrusion temperature
  • Recipe
  • Pouring time

Here more info regarding the test. Bio-plastic test

Once all the parameters from the material are well understood, is time to analyze the tool to hack.
Which part needs to be changed?
What we need to add?


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During the class, we test the WaxExtruder with the KUKA.
This test has been fundamental to understand the extruder mechanism and the possible parts to hack.

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Deliberately, I draw a no constant draw to test the nozzle capacity. How is possible to see from the picture below, the material extrusion wasn’t constant and clean.
We find the following problems:
_The metal part to close the nozzle wasn’t fitting with the internal hole. This caused the leak of the wax from the extruder.
_The pomp movement used to open and close the nozzle was splashing the material.

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Differently, in a constant draw, the extruder performance better.
Avoiding the stop during the Kuka path makes a nice draw without leaking.
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HACKING THE TOOL
I draw a technical section of the WaxExtruder, in order to have a clear view of the Wax Extruder function. In the following sections is possible to see how I suggest hacking the tool.

_1° section _existing wax extruder
_2° section _changes to make Bioplastic extruder
_3° section_hacked tool

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In red are highlight the additional piece and changes to do in the Wax extruder.

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BIOPLASTIC EXTRUDER

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