Machine design
Assigment objetive:
1- Make a machine, including the end effector build the passive parts and operate it manually document the group project and your individual contribution
BioPrinter
For this assignment what we did is a 3D Bioprinter. The vision of bioprinter develop is to provide doctors technology in order to obtain prosthetics or implants.
We are using a RepRap Mondrian 3D printer as a technological base to make this machine possible and the main innovation that we are developing is the 3D Bio extruder. We know that will takes some prototypes to have a medical bioprinter although this is the first step.
In design thinking process we started with a brainstorm in order to find the best option to build the extruder.
As a result of the brainstorm we find 2 main issues:
1. - Build a 3D printer
1.1. - Assemble the structure1.2. – Mount mechanical system
1.3. - Install electrical system
2. - Design, fabricate and taste a extruder for biomaterials
2.1. - Design schematically the extruder system2.1.1. – Identify the main issues and propose solutions
2.2. – Fabricate parts of the extruder and assemble them.
2.3. – Taste extruder system
3. - Test everything together
1. - Build a 3D printer
We started pinting 3D files, buying components and parts. And the main problem that we found is that Yachay is not near of a city and some pieces we hadn’t find. And get everything what we needed took us some various time.
1.1. - Assemble the structure
At the same time we were cutting pieces and advancing with 3D modeling and simulating the Bioextruder system.
We found some details to solve in the printed files as you can see in the next images. At the same time we were developing the extruder system hacking some medial utensils.
We find that some pieces were not compatibles with the parts that we had like motors. That means that we had tor redesign some of the pieces and adapt others.
As you can see in next image we have been designing the extruder system and redesigning it several times before building it.
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1.2. – Mount mechanical system
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1.3. - Install electrical system
Electrical Installation
My personal contribution was to implement all electrical installation.
In our FabLab was impossible to use the Gestalt Nodes becouse we don't have the RS-485 transceiver for develop FABNET PCB. Remember that FABNET is the physical layer and if you don't comunicate every physical node with the computer is impossible to control the cnc machine.
The electronic components of the printer are:
In our FabLab was impossible to use the Gestalt Nodes becouse we don't have the RS-485 transceiver for develop FABNET PCB. Remember that FABNET is the physical layer and if you don't comunicate every physical node with the computer is impossible to control the cnc machine.
Ramps 1.4 is a shield for Arduino Mega.
First, I connected steppers, endstops, drivers and LCD on the shield (RAMPS 1.4). Is important to connect all jumpers on each driver for maximun resolution. Next image is an schematic of connections.
Our printer is a replica of Falla 3D printer thus I downloaded firmware here.
For this printer I used Single Extruder Falla firmware. After to upload firmware on Arduino is necessary some changes:
- Check pin assignments in "pins.h" file.
- In "Configuration.h" file disable all temperature sensors and eneable End Stop Pullups becouse the printer has mecanical switches.
I used Repetier Host software to generate G-CODE.
Before starting printing a file is necessary edit G-CODE. Is important to delete the code "M109 S200" (wait for temperature to be reached) becouse the printer doesn't have sensor temperatures.
These were my personal contribution and this video is the test of the electrical installation of the printer.
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2. - Design, fabricate and taste a extruder for biomaterials
2.1. - Design schematically the extruder system
We have used medical syringes in order to build the system. As well we made some adaptations to incorporate check valves to Syringes Extrusion System. And we tried to use the same RepRap extruder motor stepper system to economize efforts and develop time. I mean we haven’t change the mechanical extruder RepRap system in order to have a continuous bio material flow. And that is the reason that we make Connecting Rod System. With Connecting Rod System when one stringe is pulling the other is pushing and you get a continuous material flow.
2.1.1. – Identify the main issues and propose solutions
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At the same time that we have been fabricating the bioextruder we were proving to desecrate possible errors in the system. To the first test we had use hair gel to simulate some biomaterials viscosity in different proportions.
2.2. – Fabricate parts of the extruder and assemble them.
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2.3. – Taste extruder system
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3. - Test everything together
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