Computer controlled cutting
This week we learned about cutting with the computer with two very different approaces: cutting with a CNC knife, mostly used for vinyl, and laser cutting.
Fab Lab BCN's page on computer-controlled cutting
Task
Group assignment:
- Characterize your lasercutter’s focus, power, speed, rate, kerf, joint clearance and types.
- Document your work to the group work page and reflect on your individual page what you learned.
Individual assignments
- Design, lasercut, and document a parametric construction kit, accounting for the lasercutter kerf, which can be assembled in multiple ways.
- Cut something on the vinyl cutter.
Vynil Cutting
Task: Cut something on the vinylcutter
We got an introduction to both vynil cutters here at Fab Lab BCN: a CAMM-1 Servo and a Silhouette, both from Roland. The CAMM-1 is more industrial and specialized in vynil only, while the Silhouette is smaller, for domestic use and more versatile: by changing the cutting heads you can cut other materials, like felt or
I loved the many possibilities with non-standard materials, like self-adhesive copper or felt. I'm starting by making some stickers for my laptop. I want to make some that represent the different sides of the work that we will be doing here at Fab Academy. I've created an image that represents several things that are important to me: traces and gears representing making, a light bulb representing education, and roots representing our link with our past:
I also felt down a rabbit hole. I think this has happened several times already to me in Fab Academy: we get exposed to many cool things and it is super stimulating, so I get ideas for "1-day projects" that result in huge time sinks. The first iteration of these of course doesn't work, so I have to decide whether to abandon or turn the "1-day" project into my focus for the whole week.
This time I wanted to do something to represent electronics work and cut it in the vinyl cutter. I thought of making decorative PCB traces with adhesive copper sheet, which could be really cool. Searching online I didn't find any premade vector image that I loved, so I decided to make my own. Since I was doing mine, I decided that it should represent me in some way, and I got what I think is a very cool idea: to represent the Madrid Metro map as PCB traces and do a two layer vinyl sticker: PCB green for the base then copper for the traces.
I tried using ChatGPT 4 with Dall-E 3 but the results were bad:
And (note to future me: this is were I got too carried away) I decided to do it myself. I started with this map:
I chose it from this cute page from Metro itself that shows the evolution of Metro through its maps for the XXth century. I picked this particular one because it's the one that I remember from my childhood. It also works well as a PCB trace because it has few 90º angles.
Next was drawing over it with Illustrator:
At this point I took a step back and noticed that I had spent more than an hour with that and that it was looking like it would take much longer yet. I decided to drop it. In the end I caught myself in time with this one I think, but in the future I want to be more selective with what I spend my time on.
I decided to do the Fab Academy logo instead, which only took me a few minutes to trace from an image:
They turned out pretty well! The copper foil doesn't really suggest electronics at all when cut like this. It's more of a steampunk look:
You can find the fab lab logo here and the file for the other logo here
Laser Cutting
Group assignment
I was charged with making the design for the kerf combs. I did it in Fusion and set it up so we could quickly do variants for different thickness materials
My main lesson learned here is that due to the laser cutter room computers having Rhino installed, we'd have been better off designing the thing from Rhino straight away.
You can read more about what we did on the group assignment page.
You can download the Fusion file here
Personal assignment
Task: Design, lasercut, and document a parametric press-fit construction kit, which can be assembled in multiple ways. Account for the lasercutter kerf.
Laser cutting this week was a wild ride. I wanted to use nice white cardboard that I generate as a byproduct of my side business, Horizontes Cercanos. I buy frames for the landscapes and they come with a passepartout that I don't use. I've been accumulating these because it felt like too nice of a material to just throw away, but I didn't know what to do with them. Now it's my time!
Characterizing the kerf was easy. I did it just like we did in the group assignment. The material is 1.2mm thick and the slot width needs to be .8mm for a very tight fit, .85 for a more comfy one, and .9 for a loose fit.
I started the press-fit kit design with Fusion 360. I find the constraints-based system very intuitive for this kind of shape. In order to create the n-sided profile, we had to create a single side with a given length and a slot in the midpoint, and then repeat that in a circular pattern n-times, with an internal angle of 360 degrees divided by n:
Then I projected the sketch so that it wouldn't include the construction lines, and I copied and "pasted new" (learnt my lession there) to change the angle and number of sides to use n + 1, n + 2, n + 3...
And then I sent it to the laser cutter, a Trotec 400:
It was easy enough to assemble:
The parametric lampshade
At this point, I had the individual assignment ready, so obviously it was time to fall into a rabbit hole. I've seen a bunch of parametric lampshades and they often look pretty cool. I thought that the white cardboard material I have would make a great lampshade material.
My first idea was to use the construction kit itself and build louvers and a base to connect to them at an angle. In my mind the louvers would curve in a cool way. Reality, though, had other plans:
The main problems are:
- The material is too rigid, so the louvers crease rather than curving.
- The base is subjected to too much stress and it yields.
A conversation with Max and Lena over beers and overpriced olives later, I decided to simplify the design a whole lot. In particular, I decided to make the louvers connect to the base directly, rather than I also made a discovery that changed my life forever: the region slits component in Rhino:
The results were waaaay better:
At this point, I made a serendipitous find. I misaligned one of the passepartouts for cutting, so the louver included a cut out part like an inner corner. I liked it so uch that I incorporated it into the design:
You can find the Grasshopper script here
Trotec 400: power 40, speed 2, slot .85mm
Trotec Speedy 400: power 80, speed 2, slot .85mm
Photo Stand
I also took the opportunity to build a photo stand. I designed it as a line drawing then used Grasshopper to build it into a Voronoi pattern.
I'm expecting it to be very useful for documenting our work.
The settings I used for cutting on 4.6-4.7mm plywood were: speed 0.5, power 80.
Grasshopper and Rhion files can be found here and here
Unexplored ideas and pending to do's
Idea: Marcapáginas con el cartón pluma de los paspartús.
Idea: Patapon!!???
Idea: Living hinge louvers for the lampshade
Idea: parametric external profile.
TODO: cut Spain profile out for placement of the prints.
Idea: combine origami and copper foil cutting for folded circuits.
Scarred territories
I wanted to try something out this week. One of my initial project ideas was an exploration of how violence scars the landscape
TODO: try burning one of the landscapes with violence data.
- Landscape: Spain (From thingiverse 3633068)
- Data: civil war dead?
- Al parecer no existe: https://www.mpr.gob.es/memoriademocratica/mapa-de-fosas/Paginas/index.aspx
- Buscador de fosas: https://www.mpr.gob.es/memoriademocratica/mapa-de-fosas/Paginas/buscadormapafosas.aspx
- Hay una lista de víctimas: https://pares.mcu.es/victimasGCFPortal/buscadorRaw.form
- Mapa de fosas https://desmemoria.eldiario.es/mapa-fosas/
- https://www.mpr.gob.es/memoriademocratica/mapa-de-fosas/Paginas/gu-a-de-fosas-por-comunidades-aut-nomas.aspx