Leo Lhermitte

Computer controlled cutting

Week assignments :

Cut something on the vinylcutter
design, lasercut, and document a parametric press-fit construction kit, accounting for the lasercutter kerf, which can be assembled in multiple ways

Group assignement

characterise you lasercutter, making lasercutter test part(s) that vary cutting settings and dimensions. (group project) Individual assignment

--> Link to the group assignement page <--

This week's theme is unfamiliar to me, but I am nevertheless very interested. Indeed, I have had very few opportunities to use the laser cutter and I have never used the vinyl cutter... But, the parametric press-fit construction kit give me a lot of ideas. As I said on my about me page after the fabacademy I want to join an architecture school and the press-fit construction kit is for me a very good exercice.

Vinyl cutter

Okaayy, let's start with the vinyl cutter ! I have never used it, but I know that I need a vectoriel file (here .dxf because the software of the vinyl cutter) This picture is the logo of on of my band called Finger Pain. I want to transform the white part of the logo into a sticker.

To do this I start using Inkscape in order to vectorise the logo. I import my image and I use Maj + Alt + B to vectorise a matricial object. Then I use the brightness threshold wich is in my case the most appropriate.

I click on validate and I export the file as .dxf

Then I just have to launch "silhouette studio" and in there I import my file. It look pretty good and click on send a test in order to make a little test on my adhesive vinyle.
The "force" of the blade is set to 3 and the test looks good. I place my vinyl sheet and let's see what is the result. Indeed, I really don't know if it will work because of the details of my file.

When the software is up, you just have to go in the file menu and to click on open [select your document]

Here this is the parameters that I use :

To start the machine you just have to turn it on and to connect it to your computer with the USB cable

And in order to check if the parameters are fine you can make a little test by clicking on Test on the bottom of the page !

This part is I guess the most tricky... If the material is not well placed It could move during the cutting and then failed the operation. The material must be put beetwen the two rails and fixed by putting down the two white pieces on the rod.

The result is really good and even the little hole are here and well cutted ! I used an adhesive transfer paper to transfer it on my laptop !

remove the vinyl part that is not part of the sticker
stick the adhesive tranfert
Stick the sickers and remove tha adhesive transfer paper

Press-fit construction kit

I plan to make a system composed by regular polygonale pieces and boards. As it said on the assignements my kit have to be parametric then I use FreeCAD to design it. I have create an hexagone, pentagone, and a square. And on them I have skech the shape I wanted. I have make the choice to not add a clip system, because I want to have the freedom to construct and unconstrut my constructions. Indeed, this press-fit kit is destined to be a modular game about spaces and volumes.

One of the problems I encountered was that when I drew the part I didn't know the thickness of the cardboard I was going to use. Then the power of parametric design appear (again ^^). In a first time I had put a thickness of 3mm but the reality was more something like 6.8mm. Then taking into account the kerf we had measured I have chosen a width of 7mm.

Based on the same logic of the hexagonal part I have made squares, pentagones, and boards pieces. I want to have the possibility to jungled beetwen different angles in order to make floor or roof. In order to gather my different parts from different files I have used the Assemby2 wokbench. You can really easly install it through the add-on manager. Because of time I haven't took the time use it more deeper.

Now I have my 3D models. The next step is to have an export file for the laser cutter. This type of machines use vectorised file to work like .dxf or .svg. But before exporting my file I need to create a 2D projection of my 3D object. To do that I place my camera on the top view, and I switch into the draft workbench . In the draft menu I select 2D projection of a shape. Be careful, you have to place your camera with the right angle, your projection depends on it

And this is the result ! Now we can export-it in .dxf !

Oh wait... Natively you can't export dxf file from freeCAD... Then you have to install a libraries to enable dxf support. Go on this page : https://github.com/yorikvanhavre/Draft-dxf-importer You just have to download this files.

And copy past them into the .freeCAD folder. Then restart freeCAD and now you are able to import and export dxf files. On linux don't forget to show your hidden folders and files. ls -a on a terminal or in the option of yout files explorer

Cut

Okayy, at this state most of the work is done ! In order to use the laser cutter you have to prepare your files. The cutting parts have to be in red (R 255, G 0, B 0)with a thickness of 1px ! (At the lab we have a trotec)

When its the done the first thing to do is to make the focal of the laser. Wich mean that, the pan have to be at the good height of the material in order to concentrate in single point the power of the laser. To do this you have to use the little rod given with lens.

Put the rod on the right place
Take up the board until the rod fall

Then in order to cut you need the right parameters. When you start using a new material often you have to test what is the best parameters. I have started with the basics parameters for cardboard but they cut noting ^^.

In a firts time I used this : (cardboard 7mm)

Power	Speed	Frequency
100 %	2,20 mm/s	1000 Hz

The result was good but at the back the cardboard was not cut everywhere...
Then I slowed the deplacment of the laser :

Power	Speed	Frequency
100 %	1,20 mm/s	1000 Hz

And it works very well !! Yey this cardboard is really strong :O

Assemble

More pictures of what you can do with this are coming ! But in a first time I have played with the hexagonal connector. Here my test is about the limit of the connectors and what resitance they can support. Fortunataly, my cardboard is really light and strong. Let's see what is the possibility !

Basically, the connectors work and seems to be pretty strong.
But let's try to get higher ;)

Okaayyy, here we clearly see the limit of the connectors. I have put in two of them 5 boards and I can see that the panels can no longer sink at all to the maximum because of their thickness. But the forces are pretty well distributed and I'm able to pile up 5 floor !

What I have learned

This week was really pleasant to me ! I have discovered a lot of new things and this really amusing to create this press-fit construction kit.

I have learned how to use a vinyl cutter an dhow to set it up
I have learned how to really use the laser cutter and how to set it up

About the vynil cutter, the setup was pretty easy, I'm really impressed by the details of the the cutting. By searching more about the application and implication of the vynil cutter I have learned tht we can use it in order to make flexible circuit by cutting the copper with it !

About the laser cutter, I think the setup is even easier than the vinyl... But the only thing pretty annoying is the process to send the file from the Computer to the laser cutter. When I have imported my files into Inkscape the number of bug (color, size, scale) was huge. The only way to fix it was to re-try a new importation and to shut-down the computer... But the laser cutter is still a very useful machine that allow you to create prorotype really easly !

How I can improve my press-fit construction

Make the connector bigger in order to resolve the identation problem of the boards.
Create new format of board in order to play with different dimension bigger and smaller

See you later space cowboy