4. Computer controlled cutting¶
This week I worked on defining a parametric piece to cut it in laser cut as a puzzle and exploring vinyl cutter. So I am going to tell you what I have done and how I did it.
As a remote student I am alone in the FabLab, so I have to do this part individually. *
Describing the machines¶
Vinyl cutter machine¶
In this case I am going to introduce a Vinyl cutter machine, a Roland Gs-24. You will need a 2D vector draw, and a software to cut it, in this case a free plugin for illustrator, and a machine of course.
First of all, I will draw one object in a vectorial way, because these vectors, are going to be the paths of the vinyl cutter. The program I have used is Adobe Illustrator, you have a free test mode
Just open a new file and with the Pen tool draw whatever you want.
Open the plugin in Adobe Illustrator Window > Extension > Roland Studio.
And just connect your vinyl plotter, turn it on, and follow the instructions of the screen.
Charge the vinyl roll in the backside of the plotter.
And finally check that the knife is OK.
Now is the turn of the Lasercut machine. In our case a LASERPC LPC12/90M. This type of machines works the same as a vinyl cutter machines but there is not a physic cut, it is a cut based on light. What you need to control is the speed and the power%.
As a Fab Lab, we have here a data table where we have annotated years ago the parameters correctly
The software we use is laserPc200M a software provide for the fabricants. Here I explain how to use it, but the truth is that is almost similar to all laser cutting softwares. This is the main menu, where you import your .dxf files and modifying them. with those tools.
Now you have to organize your vector (if necessary) in order of layers and adjust it power, speed and if you want that the machine blow when fire. And thats all! But you will need to cut few times to know exactly the parameters of your machine for every type of material.
We have done previously a press-fit to test the pieces.
We are going to use it to cut the parametric pieces I will describe below. But first we wanted to test some flexible patterns to cut in 3mm red methacrylate I´ve found here:
This is the configuration of the machine I have used:
Speed - 45 Corner Speed - 35 Power - 95%
This machine has a cutting board size of 120x80 cm
Parametric Design: Grasshopper¶
First of all you will need a free Rhinoceros plugin to generate a parametric design, in this case Grasshopper, and you will find it here:>
Now it is the moment to design the piece. I want to create a polygon with many variables as the number of faces, the size, and the width and depth of the slots to join each piece.
We need to insert “polygon” command connected with “area” command to obtain the centroid of the polygon as a share point with all the polygon shapes. At the same time we need to deconstruct the shape to obtain edges, vertex and faces.
Now I divide each edge in 2 parts to obtain the middle point. I discard the initial and final points of each edges(the vertex) just to work with all middle points. Later I generate the list of those points to identify at least 2 common points of all polygons (1, 2)
At this moment, I use this 2 points to create a vector direction to move a rectangle I place in vertex 1. I divide it in 2 parts to obtain the middle, and I move this rectangle to that point.
The rectangle has to be perpendicularly oriented to the edge of the polygon every time I change the number of faces. So I generate a calculation based on 360 degrees to calculate each position.
Finally we make a “polar array” with the centroid point and with as many copies as faces have the polygon. I generate a “bolean Difference” between the original polygon and the rectangles placed in each edge. Now we can play with all the variables.
You can download .gh file here: (It is no necessary a Rhino file )
How to use the parametric shape.¶
Let´s play with laser cut¶
Here is the results of all pieces fresh out of the oven.
Speed - 50 Corner Speed - 45 Power - 95%
Now it is the time to play with all the pieces combining and working all together
And play more…
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