Laser cutting

 

Laser Cutting

This is our firsts practical this semester and it is about laser cutting. We need to watch videos and do quiz in order to prepare myself for the competency test. I learnt the the different types of laser cutter there is. The laser cutter I will be using is the universal laser cutter.

This is how the laser cutter work. The laser is produced from the CO2 tube which is then reflected by mirrors into the carriage into the focal lens.

I also learnt the difference between Vector and Raster. Vector graphics are made using mathematical formulas while Raster images uses pixels. 

 

Hazards faced when laser cutting

Hazards	Safety control measures	Pictures to support the explanation
1.Materials catching on fire	Emergency stop button and fire extinguisher
2.Inhaling poisonous fumes	Exhaust to suck up the fumes
3.Small sparks and fire formed when laser cutting	Air assist to put out the flame

The materials that cant be cut

Material	Photo of material
1.PVC
2.Foam
3.Metal

 

Materials that can be cut

Material	Photo of material
1.Cardboard
2.Acrylic
3.Paper
4.Wood

 Below are the steps on the operation of UNIVERSAL laser cutter machine in FabLab:

a.    Starting the compressor, turning on the laser cutting machine and fume extractor.

Steps and description	Photos to support the description
Switch on the power for the laser cutter, Air assist and extractor.
Switch on the fume extractor

a.    Importing a .DXF file to coreldraw and modify the lines/fill for cutting and engraving.

Steps and description	Photos to support the description
Click on file and select import
Import the file into coreldraw
Ensure the file is in DXF format
Ensure line width is hairline
Click on the pen icon at the bottom right to change line color (Red for cut, Green for engrave)
Click on the block icon to change the fill color (Green for engraving)

a.     Sending the coreldraw drawing to laser cutter software and setting the laser cutter power, speed, PPI in the software.

Steps and description	Photos to support the description
Select file then click print
Click on the settings button
Click on load
Select the material type and thickness
Some important details you need to check before you send it for cut! POWER: describes the output power of the laser. 100% is maximum power (will cause ugly charring). For dark wood engravings or stamp engravings, you generally need high power, whereas low values are used for materials such as paper. SPEED: describes the movement of the laser head. Fast speeds lead to short exposure times, slow speeds lead to long exposure times. PPI: Pulses Per Inch, Frequency may also be known as PPI or pulses per inch and is a way to control how many times the laser pulses over a given distance during the cutting process. The higher the frequency the more pulses you have and the more they will overlap resulting in a smoother cut, however the downside to this is that the higher the frequency the more heat it creates while cutting which can cause melting or charring on certain materials. Z-Axis: Usually set as the material height for optimal focus point

 Starting the job on the laser cutter machine.

Open the Universal Control Panel
Click ok to start printing
Click on the red button to start printing
Shut the lid
Click the play button to start printing
Click the pause the button to un-pause and pause

          

Shut down

Steps and description	Photos to support the description
Leave the lid close for 1 min to allow the extractor to remove the poisonous fumes
Deactivate the laser cutter by clicking the red button
Discard waste material into bin

      DOs and DONTs when there’s flame/fire on the material being cut.

DOs and DONTs	Photos to support the description
Do lift up the lid when there is a small fire
Do not use a fire extinguish when there is a small fire
Do not attempt to blow out the flame when there is a huge fire
Do use a fire extinguisher when there is a huge fire
Do press the Emergency stop button when there is a huge fire

 My learning reflection

Before i read up on laser cutting and attempted it, i thought it was a tedious and difficult task. Therefore i did not have much interest in laser cutting. However, after i read and attempted laser cutting, i find it to be very interesting and fun. I find the working mechanism of the laser cutter very interesting. Seeing the design being cut during the competency test makes me want to cut more stuff. It made me want to design in Fusion and cut my own design. I would say this practical was a 10/10 as i truly enjoyed myself. I learnt alot of stuff during this practical. I learnt the difference between raster and vector image. All this while, i thought that all images are in pixels. I also learn the working mechanism of the laser cutter. I did not know that the laser is made by a CO2 tube and have always thought that it was jus a very focused beam of light. This practical was one of the most interesting ones and i would definitely do it again.