As many of these labs, what seemed like a simple task grew into much more of a challenge than I expected. My partner and I unfortunately lost most of our laser cutting time during class and couldn’t find a time that worked for us to reschedule, so I ended up doing most of this work on my own. Fortunately there are enough people at the OEDK (both lab techs, design projects, and hobbyists) that I was able to brainstorm and figure out problems with other people. For the rest, I did some prototyping and brainstorming on my own.

Prepping the File:

The piece I was creating for the prototyping library was the box example. Boxes are perhaps the single most created thing on the laser cutter, so I was excited to create an example box. Before I could cut anything I got the file off of the prototyping library website, downloaded it, opened it in Adobe Illustrator (see image left). I edited the text to include the correct information.

The first issue I ran into was that the file was physically very large. In its original form the file was over two square feet of space. I moved the boxes so they were more consolidated on the page. Even then the file was still 10 1/2 by 14 inches. To cut the original file I couldn’t use the scrap material, but had to ask the ODEK lab techs for a fresh sheet. This bumped my material thickness from 3 mm to 4 mm, an issue I didn’t think would be a problem at the time, but would be an issue later.

The Cutting Process:

From others I had an idea about what the settings should be for this material. It was 3 & 100. I put the numbers in and ran the file. It engraved the preset text and then stopped. I deleted the text and exported the file again. Nothing happened. I had run into my first issue. I double checked the file and realized that when I had downloaded it a second time I had not reset the cutting elements settings. The default on the file was zero point. The first time I had run the file I had corrected this issue but when I returned to the file I had forgotten to repeat that step. Problem solved.

I ran the file again and it went through the motions, but didn’t cut anything. For those who recognize laser cutter settings in the previous paragraph probably recognized the problem. The power & speed settings are 3&100 but very importantly power is 100 and speed is 3. I had set the instructions the opposite direction. Once fixed I was able to cut out a small sample cube of material to check the settings.

Final Result:

This was how the final result of the cuts turned out. The cuts were very clean on the top layer and mostly clean on the bottom layer. Everything was cut out so I would be hesitant to scale back the power and everything was a dark maple color so I would hesitate to scale up the speed or up the power. The raster settings were also spot on with 50 speed and 50 power. So that’s the end of the project right? Everything is cut out and fine?

Wrong. (Rhetorical question I know.) I would recommend not having a preset file for the laser cutting library for the box. Remember that issue I had foreshadowed earlier with the changing of the thickness? Most laser cut experts know what the issue is though the novice laser cutter I am I did not recognize it until I went to put the pieces together Sunday night. The image on the left is a screenshot of a website called box designer, the basis of the box adobe file. One of the dimensions you need to input is a material thickness. This is because if you don’t input the thickness when creating the file, the crenelations won’t be deep enough and the box edges won’t sit flush.

Returning us to the issue at hand, I had swapped out the standard 3mm material for 4mm material because the OEDK did not have any 3mm material that was large enough for the file. When the box is put together the pieces fit but are not flush to the edge. This is because the original file had a built in function of thickness that cannot always be replicated. For this reason I would advocate against having a set file for the prototyping box and instead advocate to a file of the raster settings, a link to the box designer website and instructions for how to create a box for a prototyping library.