Laser Cutting Practical

 For my first practical, I learnt how to operate a laser cutter and use it to cut a parametric tool kit. But to ensure I am qualified  to run a laser cutter, first I had to get full marks for a mandatory quiz and also pass the practical test where I was tested on all the different components of the laser cutter and demonstrated how to cut a design from a panel of wood to under the supervision of an examiner before I would be cleared to operate the laser cutter on my own to be able to cut out my parametric design.

First, I created an operating procedure as a guide on what to do and what to avoid before, during and after laser cutting. After the practical, I revisited the SOP and improved it using what I had learnt during the practical. The improved SOP can be seen below.

Safety

1. Do not wear anything hanging from the neck

2. Tie up long hair

3. Open cover fully

4. Do not put head under the cover

5. Do not slam the cover

6. Check green lit LEDS to know if cover is fully closed

7. When cutting, do not lean over the cover

8. Do not cut metals, foam or chlorine containing materials

9.  Do not stare into the beam while cutting

10. Check that the focus lens is clean

Start Up

1. Turn on the air compressor (red switch)

2. Turn on the fume extractor (green button)

3. Turn on the main laser cutter (black switch)

4. Wait for laser cutter to finish initialization 

5. Proceed to workstation for uploading of drawing/design

CorelDraw to Print

1. Use Vernier calipers to measure the thickness of the material 

2. Import DXF or SVG file

3. Set line weight, color and fill depending on your needs [cutting, engraving or scoring] (Vector Cutting: Red, hairline, no fill) (Engrave: Green, no weight, Green fill) (Engrave Etch/Score: Green, hairline, no fill)

4. Click print when ready

5. Turn on Auto Focus (thickness)

6. Select drawing and click import material settings and choose the material used for cutting

Note: Under import material settings there are 2 tabs: Engrave and Vector. Use Engrave tab for engraving, Vector tab for cutting

8. Type in the thickness of the cutting material measured in step 1

9. Turn on air assist

10. Click print 

11. On the laser cutting machine, verify the name of the file you are cutting and estimated cutting time

12. Place cutting material into laser cutter.

13. Close fume hood fully. Ensure that the two LEDs at the side are lit up.

14. Press the green button "GO/PLAY"

15. After printing is complete, wait for 1 minute

16. Open the cover fully and remove the cut design

Shutdown

1. Remove any materials in the laser cutter

2. Turn off the main laser cutter (black switch)

3. Turn off fume extractor (green button)

4. Turn off air compressor (red button)

5. Perform housekeeping

Using CorelDraw

• First, to import my Fusion 360 file from Fusion 360, a thumbdrive is needed and the imported file must be a .dxf or a .svg file.

• By following the above steps, the design should appear on the screen, an example is shown below.

• There are different settings for different actions that you want to be taken by the laser cutter to create your design. There is cutting where the design is cut from the material, engraving where the design is engraved into the the material, and scoring where the design is scored into the material. The settings for each action are collated below.

• When all this is done, you can click print to send the file to the Epilog Dashboard interface.

Using Epilog Dashboard

• Ensure that auto focus is turned on or set to 'thickness', you can find the setting on the top right of the screen

• Right below that red box above is a file that contains your design, to set the material that you would be cutting the design out of, click the folder icon on the top right of the tab. This should send you to the library to choose the material and its thickness. For the practical, we used 5mm thick plywood. Note: For engraving, set the power to 30%
• After which the design is good to go. Press the print button to send the file to the laser cutter.

Using Laser Cutter

• On the screen of the laser cutter, the file name of the design you sent to the laser cutter would appear. Double check the file name is correct.
• Next, place the material you would be cutting in the laser cutter. In my case, I would place a panel of plywood in the laser cutter.
• In the event that the cutting material used has been used before, simply flip the material until a corner that has not been touched is placed at the top left of the cutter since the laser cutter cuts from the top left of the material. However, if there are no untouched corners, there is an option to manually move the cutter to an untouched area of the material. This can also be used to save material during cutting. To exercise this option, switch the mode to jog and use the joystick to direct the laser cutter to an area to begin cutting out your design.
• When all previous steps have been completed, click GO to start printing. The display would also give you an estimate of when the printing would be completed in the form of a countdown. 
• For safety, after the cutting is completed, wait 1 minute before lifting the cover of the laser cutter. This is to allow the fume extractor to remove any harmful fumes that may have been released during the cutting process.
• This is what my team and I cut after many revisions of our design and many test cuts!

This practical was an interesting one. First, I learnt how to use parametric design in my sketches in Fusion 360. 

I initially thought it was redundant as as long as I kept all the measurements equal, the design would be fine, but I learnt the parameters used in the parametric design can be changed which results in a change in all the lengths that used the parameter in the design in an instant. It was a great time saver and also ensures that I did not miss out any length that I left unaltered. This came especially helpful during our cutting process as we had to do so many test cuts, slightly altering the dimensions of our notches or grooves for a tight fit. 

I also learnt from this practical that even given measurements can be wrong. For example, the 5mm thick plywood we used as our material was actually 4.5mm thick! My team and I only found out after we did multiple test cuts where the fittings between pieces were loose and our lecturer suggested we confirm the thickness of the material. From then, we managed to get a tight fit as can be seen above, but the experience was a great learning experience and something that I can make use of in the future. This practical has also given me the skills needed to laser cut designs which would be extremely useful for my future projects to craft a prototype. 

Overall, this practical has been a very memorable and extremely useful one.