Lesson 3 | Laser Cutting

Assignment for the week:

- make a 2D design that will be made using the following laser cutting techniques:

    -cutting

    -engraving

    - cutting joints (to join the parts together)

- cut the design with the laser cutter and assembly it

- create a page to document your progress of week 3, what did you do, in which order, what are your experiences (problems, solutions, etc.), and add the download of the laser cut design to it


Used Software:

    - Autodesk Fusion360

    - LibreCAD

    - VisiCut

Downloads:

    Software:
             - Fusion360

            - LibreCAD

            - VisiCut

     2D Files
             Download

             This zip-File include the .dxf file of my 2D Prototyp

Idea:

Since I always wanted to build an extra keypad for the important shortcuts in Fusion360, but never got further than the electronic part (cabling and programming), this week I'm building a box for the keypad. After completion, this project will be uploaded to my Repositories on github.com or to gitlab.com

2D Design:

First I create a 2D model of all pages in Fusion360. Since I want to make sure that the box is stable, I use 5mm MDF panels. To connect the parts, I draw joins in all parts of the box. The joins are 5mm long. After this I added the lettering in LibreCAD.


A first version without the joins

A first version without the joins


Creating the joins with auxiliary lines

Creating the joins with auxiliary lines


Joins

Joins


The final prototyp

The final prototyp


The final prototyp

The final prototyp


After I finished the 2D-drawing, I extruded the single parts to 5mm and made a body out of every single part. I put these parts together with the Joint-Function and checked if all parts fit.



When cutting wood (and other materials) by laser, a so-called "Kerf" is formed at the cutting edges. This is the material that the laser burns and "sticks" to the cut edges. As a result, the components no longer fit later. The easiest way to add this Kerf is by using parameters. But since I didn't use any parameters in the drawing, I had to choose another way to make the parts fit. I then choose the path from Ole Langenbach. He creates a new tool in CAM mode that has the width of the Kerfs as the cutting width. This enlarges the drawing in the postprocessor by this Kerf. The complete manual can be found with this link (Unfortunately only accessible from the HSRW network).

The final prototyp

The final prototpy


>

Change to Compentions Typ = in Computer


Export the file as .dxf

Export the file as .dxf


The Lasercutter:

We at the Fablab have two laser cutters, a 60W and a 30W laser. I used the 30W lasercutter from Epilog. To control the lasercutter and to create the cutting jobs I use the FOSS tool "VisiCut".

The Lasercutter

The Lasercutter


First of all I had to find the right settings for the respective wood. For this I created a small square and then played with different parameters. After a few tries I found the right settings for my 5mm MDF board.
For cutting:
Power Speed Focus Frequency
100 20 0 4000

For engraving:
Power Speed Focus
50 50 0

After I found the appropriate values, I loaded the .dxf file with the case into VisiCut. After setting the appropriate values, I could calculate the cutting time by clicking on "Calculate". With a subsequent click on "Execute" the order is sent to the laser cutter. At the lasercutter the starting position and the focus (distance laser - wood) have to be adjusted. With this device, the XY start position must be set manually. The same applies to the focus. Then the job can be started. At the end of the job you only have to remove the parts from the wooden plate. If the parameters are correct, you hardly have to apply pressure.

Loading the dxf-File into VisiCut

Loading the dxf-File into VisiCut


While Cutting

While Cutting


After the lasercutter finish his job

After the lasercutter finish his job


The prototyp

The prototyp


The prototyp

The prototyp


Issues:

- Since I didn't use any parameters for drawing the joins, it wasn't so easy to change from 5mm to 3mm, because I had to change all connectors manually. I also could not integrate a Kerf directly into the drawing but had to go the way over the postprocessor. With the next drawing I will pay attention to parameterize everything.