4. Fablab tools#

The fablab tools I choosed to learn about are the laser cutter and 3d repairing.

Laser cutter#

A laser cutter is a device used to engrave or cut materials with high precision using a laser. This can be done in two different ways. Firstly, the vectorial method which consists of the laser moving while following lines. Secondly, an approach where the laser emits radiations points (engraving).

Safety measure#

Laser cutters are highly powerful tools that require a lot of caution. Here is a guide on the safety measures.

Design#

Laser cutters take as input an svg file. The schematic should be composed of different colors for which we will then assign the treatment wished by the laser cutter.

To do that, I decided to use inkscape, a free and open-source software which helped me make my schemes in a very simple way. We should be careful to convert text to paths (SVG) or else it won’t be understood by the laser cutter.

Epilog Fusion Pro#

Once we have our file ready in inkscape we can then try to print it but instead of selecting a printer, we select the laser cutter. We can then assign each color of our schematic to an action the laser cutter will execute, be it cutting or engraving. In the Epilog Fusion Pro, speed and power are the parameters we can modify.

Lasersaur#

The Lasersaur is a more powerful laser cutter than the Epilog Fusion Pro. It works by importing an stl file. It’s less user friendly as there is no camera and also require more precautions to be taken.

I unfortunately didn’t get the occasion to use this laser cutter.

Test Exercise#

I laser cut a house to test the Epilog Fusion Pro. Here is the result. Each color will be assigned to a specific action in the laser cutter (cutting or engraving). This is how we can have cuts of different depths and different levels of engraving.

Kerf#

The kerf is the width of the cut line made by the laser cutter. It’s important to know the kerf of each laser cutter as it allows to prepare for the error factor when drawing the scheme.

Speed and Power Test#

This exercise consists of testing different measures of power for a fixed speed or vice-versa. The laser’s penetration increases as power is high and as the speed is low.

Piece assembly Test#

The objective of this exercise was to design multiple pieces which once reunited would assemble to create a unique object. I designed a weird object which I must admit is hard to describe. Let’s say that it is composed of a base with two walls placed on opposite sides which are then linked with a plank that goes above those walls.

Lack of Laser Cutting#

Unfortunately, I couldn’t laser cut all my pieces even though I had all my svg files ready. A lot of formations were given and the bookings of the laser cutters were heavily contested.

What I learned#

Laser cutters are a very efficient method to cut various materials precisely. By adjusting correctly the speed and power of the laser, it is even possible to decide the depth of the cuts. It can also be used to make pretty engraving.

3D Printing For Repair#

Repair Together fights against programmed obsolescence. They fight for the right to repair. Here is a small picture illustrating the different states objects pass through in their lifetime. We can see that repair is the fastest way to give value to a defective object.

Electric circuit Repair#

The first exercise was to repair a defective circuit we were given. We had to pinpoint what was wrong using a multimeter.

After testing if current was passing in cables, I was able to pinpoint the problem. The switch was defective. But even after changing the switch I happened to find a second problem. A cable was burned and thus not working properly. I found two problems for the price of one.

I had a hard time finding the problem so I was taught to unplug the battery as it could cause issues when looking for short circuits.

Electrical components#

We were then presented some often used electrical components.

From left to right, the components we have are : LED, ceramic capacitor, capacitor, electrolytic capacitor, capacitor, diode, electrical fuse, resistor, thermal fuse.

3D Repair#

Here are the 4 steps to follow (full guide):

  • Analyse:
    • Check if the piece exists online
    • Check if the piece is not too broken
  • Reconception:
    • Use tool to measure dimensions
    • Think about how to design the piece, put it in the correct position to need as few supports as possible.
  • Fabrication:
    • Choose the material
    • Print the piece and do some post treatment if necessary
  • Test:
    • Analyse it visually
    • Test its weights and its dimensions

Choosing the piece#

I worked with Lawra Derhaag on this exercise.

We wanted to created a spare piece of a tripod which is likely to break in the future.

Measurments#

Measurments took lots of time as it was a difficult piece with complex forms.

Design#

We designed it with OpenScad. In order to account for the errors in the measurements due to the kerf, error factors are taken into account in the SCAD design file.

Testing#

Here is the final printed result.

It was a decent piece but still had some issues: - The length of the piece was too small - The holes weren’t big enough and weren’t well positioned

We unfortunately ran out of time after printing this piece but from here, it’s just a game of try and retry until it fits perfectly.

What I learned#

3D printing is excellent to create custom pieces to repair objects of relatively small sizes. It allows to repair broken pieces for cheap and even custom them for improvements !

License#

CC BY-NC-SA 4.0