P1: Laser Cutter

 Welcome back to our blog!

For this entry, my team was tasked to create shapes using parametric design that work just like jigsaw pieces. Furthermore, we had to use the laser cutter ourselves to cut the shapes!

We first made an SOP, and then did an individual segment to qualify ourselves to use the laser cutter. After some advice from our respective TEs, we found a few changes we had to create. Here is our improved SOP:

Purpose	To make a tower using at least 2 different types of building blocks created from wood.
Scope	Ensure the safety of the user by following the instructions in this document
Responsibilities	Leader: Miguel Supervises general use of laser cutter Timekeeper for the team Laser Cutter Operator: Brayden Operates the laser cutter Follows operation procedure and safety measures of laser cutter Designer: Jun Weng Create the items needed on Fusion360 and export as a .dxf file to a thumbdrive.
Definitions	Refer to practical materials.
Safety	Tie up long hair, and flip up any long fringe Remove any items around your neck/on your body before use. Do not slant the cover. Open the cover fully When closing the cover, ensure that the 2 green LED lights on the right side (interlock LED) are turned on. Do not stare directly at the laser. Safety Interlocks: Cover cannot be lifted up during cutting
Materials	Wood
Equipment	Air compressor Fume extractor Laser cutter Ipad (for Fusion360 designs)

Operating Procedures

Turn on air compressor Turn on the laser cutter by pressing the power button right below the laser cutter set-up. Turn on the fume extractor by pressing the green button on the left side. Import the DXF/SVG file into Coreldraw.  Set line weight, colour and fill to the desired method: cutting, engraving or scoring. Send to print by pressing Ctrl + P on the desktop, and clicking print. This should open a new interface for the Epilog laser cutter. Choose autofocus/thickness: on, and air assist: on in Epilog dashboard Load material library to choose which material for cutting/engraving When done, click print to send the file to the laser cutter Move to the laser cutter and check the file name and the estimated time to cut on the LCD screen Once confirmed, click the ‘GO’ button to start. Allow the laser cutter to cut the shapes. After the job is completed, wait ~1 minute to allow the fume extractor to remove any leftover fumes before taking out the cut material. Repeat steps 4-12 as many times as needed. Turn off the laser cutter by pressing the power button right below the laser cutter set-up. Once complete, remove any residue materials from the laser cutter workspace. Turn off the air compressor. Turn off the fume extractor by pressing the green button on the left side. Do general housekeeping and ensure all electronics are off before leaving.

The ones in red were the amended steps as the order of how we turned on and off the laser cutter were different. The order when turning on would be the air compressor, laser cutter then fume extractor, while the turning off order is the opposite, fume extractor first, laser cutter and then air compressor.

We also learnt how to import the DXF file from a Fusion360 file. One must select the shape face that would be cut through the laser cutter. Right-click the face, and then press "create sketch". Select this sketch and export as a DXF file. When uploaded in Coreldraw, the image should be flat.

To elaborate on step 5, the settings used for the different type of cutting are as follows:

- For vector cutting, the line colour must be red and line weight must be hairline.

- For engraving, the line colour must be green, and the shape must be filled with green.

- For etching/scoring, the line colour must be green and the line weight must be hairline.

We noticed how important the colour would be in deciding the actual cutting, as it may make or break the creation.

Well, that's enough of words. Here's a photo of my assessment "evidence":

Next, we had to start creating our "jigsaw pieces". We made sure to create kerfs, which are slots that are slightly smaller to the actual thickness to allow a tight grip between the pieces. We found a good deal of difficulty, such as mistakenly assuming that the material we're using has the same thickness as its factory default, when it could possibly be lesser or more than that. 

For example, our first try had a problem with non-tight grip as the thickness was 0.5mm smaller than expected. This caused us to have to adjust parameters in our original file such that the thickness and kerfs are good enough.

Another problem was using different materials. Despite them having the same assumed thickness, plastic has a much more variable thickness and it opened a different can of worms when we used our updated design with it. As we originally started with wood, we returned to the material as we've fixed most of the problems from there, rather than using a plastic medium.

Despite that, we were able to persevere and modify as much as possible, to create two pieces that grip very well to each other! Here's our 4 attempts:

Sadly, we were unable to mass produce these pieces. :( However, our big plan would've been to create a very elaborate 3-pronged tower.

I learnt a great deal about the laser cutter and its functions. I opened my eyes to the bigger opportunities I can get from using a laser cutter and can't wait to use it a next time.

Overall, I enjoyed operating the laser cutter and seeing the end product, despite it needing design tweaks when necessary. I also really learnt a lot from troubleshooting our 3 other attempts before the proper final one, as this was the first time using a laser cutter. Getting it right won't happen without a few mistakes!

Thank you for reading!