11. Open Source Hardware - From Fibers to Fabric¶
Research & Ideation¶
For this week's assignment, all the people at the lab worked together to build a machine for a specific task. We all gave different ideas, for example a wall painting/drawing machine, an origami scoring machine, an extrusion deposition machine, etc. and voted to get the final machine, which is a Origami scoring machine.
We used the principle for CNC (Computer Numeric Control) and tried (so many times) until we got it right. Let's start with the begining.
What is CNC As we have been using them, all the digital fabrication machines work with this principle, which gives the machine commands on where to move, what to do while moving, and even at which speed it should be moving, with a file called Gcode. This gcode is a text file, most of the times, with hundreds of thousands of lines where it tells the machine what to do on each one. For example 3D printers move on the X, Y and Z axis and deposition material; Laser cutters move to different points and activate/deactivate the laser beam, CNC Routers move the spindle while cutting, etc.
So now this machine that we are building, should score the surface of the paper, gently so it doesn´t break. The paper should be over a soft bed which allows the scoring to be deep enough, but also fixes it, so it doesn't move either.
We took some inspiration from the internet and the amazing website How to build your own CNC machine.
For this machine we worked with an already existing CNC controller called Makerbase, and based our design on a generic CNC Minimill for cutting PCB and carving small sculptures.
The Gcode¶
It was a bit difficult to wrap my head around how was de gcode going to be generated for our machine, and I thought about different alternatives:
- Create a custom 3D printer in Ultimaker Cura, and it was important that it could do a little hop on the z-axis everytime. The problem is that Cura is expecting a 3D model, or an image and not some vectors.
- Treat the gcode as a laser gcode but instead of activating/deactivating the laser, moving the pen up and down accordingly, but that was also very hard to do as it was necessary to modify the export code and syntax.
- Use the InkScape extensions for vinyl cutting and treating our machine as a vinyl cutter, as it works similarly to the origami machine.
- Treat the machine as a drawing machine, but instead of a pen, we use the pointy tool for denting the surface of the paper.
- Treat the machine as a CNC Router without a spindle and hope for the best.
After thinking about the solutions, pros and cons of each one, and doing some research online, the best option is the CNC router imposter, as the Vectric Vcarve software is optimized for this kind of paths and operations. The design was drawn in Inkscape as a vector and exported in .dxf format. Then uploaded to Vcarve for the proper configuration. A new tool was created for this operation, which needs 0 rpm and a slow feed rate, little depth per pass, etc. The final gcode was exported and tested on the open-source software Gsender, which can control the machine. The first step with the Gsender is to zero every axis with the Zero X, Zero Y and Zero Z buttons, while having moved the tool to the lower-left corner of the area. I ran some tests high enough, so the tool doesn’t touch the base, and voilá! It worked.
Also the adapter tool for scoring was designed with Onshape and printed in resin for resistance.
The machine¶
We modified the original machine for our purpose, and even redesigned and built a case.
I recommend checking my teamate's websites for this machine:
How does it work?¶
How can we get a working vector for an origami model? What we did first was fold the paper as we already knew how to create a little boat, then very carefully we unfolded it, and from those lines we traced the vector drawing that will be reproduced by the machine. Further development will make this process more intuitive, even automate it with software like Slicer for Fusion 360 or Pepakura designer
The process was done through Vcarve, using the custom tool we prepared, and sent as .gcode I ran it from the Gsender app, after configuring X, Y and Z axii. There will be 5 passes so the paper is perfectly scored and easy to fold afterwards.
