_Week03_ COMPUTER-CONTROLLED CUTTING

_Introduction

During this week we could begin to see the principles of computer controlled cutting using the laser cutter and the vinyl cutter, using different materials and testing some design rules for each material and joints needed to cut and assemble any design we wanted. We could also see different ways to handle 2D tools that facilitate the desired design.

_Background

The computer controlled cutting is based on handling directly from the computer the cut in some of the machines in which it is possible to establish cutting parameters for each software, design and material; In these machines we can cut, engrave and also just mark the material this will depend on the established design and how we handle the parameters in the configuration of the machine.

Machines used in this assignment availables in the FabLab BCN:

_Week Assignments

Group assignment:

  • Make lasercutter test part(s), varying cutting settings and slot dimensions.
  • Individual assignment:

  • Cut something on the vinylcutter
  • Design, make, and document a parametric press-fit construction kit,accounting for the lasercutter kerf, which can be assembled in multiple ways.
  • _Workflow /Step by Step

    _Group assignment cardboard

    For this excersice we went through a laser cut tutorial for how to use the machines correctly with all the safety instructions, then we started to model in Rhinoceros the cardboard pressfit file. The design is based in the thickness of the material (this case 3mm) in order to create the right kind of joint, also create layers for cutting and just for the number marks. Calibrating the lasercutter making some test with differents parameters.

    For cut 3mm cardboard:

  • Speed : 15%
  • Power : 100%
  • For engrave 3mm cardboard:

  • Speed : 90%
  • Power : 10%
  • Secondly, we try with certains parameters for the laser cutting machines of the fab lab Barcelona using Rhinoceros for uploading the files into the Epilog laser machine but the machine burned a lot and didnt cut the cardboard because another person used incorrectly so the glasses get so dirty, so we change to the Spirit GE laser pro that have very good quality and we could cut very good the cardboard. So the joints worked perfectly in each size that we putted.

    _Vynil cut test.

    For the vynil cut test I worked with Inkscape for doing the vectors of the letters that i wanted to cut in order to change the raster software (normally I use Photoshop), so for manage all the files that we want to cut or laser cut in the machines we have to put the files in the IAAC CLOUD that share in the internal system of the lab.

    NOTE: It´s so important that the raster file have to be correctly made and no so heavy because this will cause the computer crash down before you cut the vynil.

    Afterwards, I put the file into the Vinyl cutter GX-24 Camm Servo software for upload to the machine, then I have to ajust the razor and also the size of the sheet of vynil that i putted in the machine. Later I put the final product in my laptop.

    _Press fit cardboard excercise

    I like so much this excercise of press fit because I made all the files from scratch (with the help of the good Santi), first I was trying by myself only with Rhinoceros but then i asked for some help to start building one part of all the set for starting see how I can get a physical approach to the final project, all in Grasshopper.

    Design workflow in Grasshopper:

  • Create a circle with a π(pi) operation and divide it in 2 for having a quarter of an arc putting the center in the 0,0 with a panel and also put the mesures that I need with and slider.
  • Once that I got the arc, I create an Offset in negative with the width of the piece defined by a slider.
  • Then find the End points of each arc and Join curves.
  • Also join these two points with a Line and finding the midpoint with Point on curve this in order to create the joints of the pieces.
  • For finishing the joints, I create Rectangles with the size of the thickness of the material at the midpoints of the last curves that I builded; those rectangles with be in the Negative area (to putted inside the form) and then just create a Region difference between the whole curve and those rectangles and Bake the result lines.
  • For cutting the file, I worked also with the Spirit laser cutter with the same parameters:

  • Speed : 15%
  • Power : 100%
  • Using Rhinoceros I put the file in the correct size of the panel of cardboard and send it. The pieces fit so well but the joints were a little bit tiny for fitting steady, thus I have to make bigger inside the form for engage better.

    _FILES

    All the files for this assignment are available to download here