This assignment was my first time using a laser cutter. First I made some test cuts and engravings in a corner of my sheet of wood. For cutting, I cut a small 1″x1″ square in the corner. At first I used the default recommended settings for a sheet of wood, 18% speed and 100% power, but there was a little more charring than I would have liked. So I increased the speed to 22% for future cuts. I also decided to cover my laser cutting area with tape to help further protect from charring. For engraving, I wanted to put a NASA logo on my box since I am a space guy and currently intern at Johnson Space Center. I found a few png and vector files online and tried them out on tape with various speed and power settings. For the sake of time, I tried to keep speed at 100% so that the laser cutter would print faster. I ended up choosing the vector file that created the right most logo at a power of 60% with 100% speed (600 DPI). I also played around with the dither settings a bit, but after also reading through the Epilog manual the standard setting seemed sufficient.

With the cutting and engraving laser settings set, now I try to find the kerf of the laser. In Adobe Illustrator, I drew a rectangle with 8 vertical lines cutting through it for a total of 10 vertical lines. I then cut this out along the top edge of my wood (near my test cuts) with the laser cutter. This will cut out 8 strips of wood in the rectangle. Keeping all the pieces in place, I pressed all the strips of wood to one side (making sure they’re not popping out), creating a larger gap on the other side that should equal to 10 times the kerf (sum of 10 vertical lines cut out). I measured this gap with a micrometer, divided the result by 10, and used that value as my kerf.

To make the layout of the box, I used the MakerCase website given in class. Using calipers I measured the thickness of the wood around all four sides of the sheet and averaged the result, with the end number being what is entered into the website. The width, height, and depth are 4″ x 4″ x 4″ as inside dimensions (so my box can be slightly bigger). I adjusted the finger joint size until I had a nice looking set of 3 finger joints on each side. The kerf value previously measured is also input to get a nice box layout svg file.

In Illustrator, I rearranged the layout of the box faces into an easier-to-picture T-shaped layout and deleted the “front”, “top”, “back”, etc. labels. I put my name, class, and semester on one side and my college crest, Weiss, (downloaded from Canvas) on the opposite side. I also wanted to put the logos of the two places I’ve interned at this year on my box. So I downloaded the svg files for the NASA and Axiom Space logos and put them on opposite sides of the box, between my name and the college crest. I noticed that when loading the resulting file into the Epilog software, the program saw the edges of the letters in my text and the Axiom logo as vector cuts instead of engraving. Luckily, it was only the edges and I could easily separate it using split by color in the program (these were black, the box vector cuts were red) and turning off those vector cuts.

To protect the wood from charring, I covered the sheet of wood with masking tape. This process took a while and used a decent amount of tape. There is also some offset between the image displayed on the laser cutting software and where it actually cuts, so I had to be more generous with how much area I covered since I wasn’t sure where the laser would exactly go. I loaded up the file, placed it more up and to the left of where I placed the tape (as that is the offset I saw during my test cuts), input the settings discussed beforehand, and let the laser cutter do its thing.

At the end, the offset between the display and the actual cutting location was a lot less than I anticipated. I think I was imagining the offset relative to the smaller cuts I was doing with the test cuts and unconsciously scaled it up to the bigger cut job even though the offset would not scale. Also, the offset was not consistent across the image it was cutting, the cut was to the right of the display on the left-hand side but it was to the right of the display on the right hand-side (and there was more offset towards the top and not much towards the bottom). It seems there is a curvature to the camera image. As a result, part of the laser cutting job did go outside of where I put the tape.

I also noticed that my taping was not perfect. There was some areas where some strips of tape overlapped, and it can be seen in the engravings. Where the tape overlapped, the engravings are more shallow and lighter, looking like lines along the engraved images. I should have been more careful with the tape placement. It also seems that one small cut, all the way towards the left near the edge of the wood, did not cut all the way through even though everywhere else did. This is probably due to the wood being thicker or denser in that specific area, it was not the tape as there wasn’t any more tape in the affected area than other places. This could be fixed by being more generous with the laser settings (lower speed) as I shouldn’t be as worried about charring if I’m putting on tape.

Speaking of charring, adding tape did not really help all that much. The places where there was tape still had some charring and the section where there was no tape where it cut did not have much more charring compared to the rest. The tape was also tedious to remove and at some points I had to use Goof-Off to remove the glue as it had become too stuck to the wood. Tape was tedious to put on and tedious to take off, with not much difference in the result compared to areas without tape. I would not use tape next time and would instead do smaller cuts with more careful settings.

Cost Type	Cost	Price	Source	Quantity	Total
Materials	¼” wood (2’ x 2’)	$8.98 /sheet	Lowes.com (first item – 1/4 in x 2ft Lauan Sanded Plywood)	1 sheet	$8.98
	Painter’s tape	$0.083 /yd	Homedepot.com	6.7 yds	$0.55
Labor	Laser Cutter Operator	$19.32 /hr	Indeed.com	1 hr	$19.32
	Prototyping Engineer (designing the box)	$39 /hr	Salary.com	0.25 hr	$9.75
Overhead	Facility Cost (Machine Time)	$100 /hr	Lightobject.com	1.5 hrs	$150
	Quality Control	$20.72 /hr	Indeed.com	0.25 hr	$5.18
Design	Engineering and Development		Covered in Prototyping Engineer		$0
	Iterations		No additional iterations made	1	$0
Misc.	Waste and Scrap	$8.98 /sheet	Whole wood sheet already included in materials	0	$0

Total: $193.78 (more than 3/4 of the price is just the laser cutter machine)