Hello everyone! It is Monday, September 29th, and I have finished my attempt at laser cutting. Here’s how that went.

I’ve decided to push myself (again) and go for the proficient project for this assignment. I settled on a train carriage model, where each carriage features a laser-cut compartment (open-lid box) on top that contains future EDES 210 projects, including the plasma-cut diamonds and the final chess piece.

Additionally, I wanted to experiment with the Nikon Z5 camera I had rented from Fondren Library. I had used it to take photos at an earlier event, but since I still had it around, I decided to use the camera to photograph my making process. This post is thus my first attempt at high-quality engineering photography. I hope you appreciate the photos that came out of this great camera.

First, I determined the kerf for the Epilog Fusion Pro laser cutter by cutting out a kerf box, as shown in the image below. I used calipers to measure that the kerf is approximately 0.04 inches, which is not typical of the range of kerfs for 1/4-inch. plywood. I thus had to use the commonly used 0.004 inches for the boxes.

The kerf box.

To create the five boxes for the carriage train, I used the MakerCase software with the provided project dimensions on the Canvas page. I also used these settings to make the boxes:

• 0.004 in. kerf
• 0.56 in. finger size
• All dimensions used are outside dimensions
• 0.2 in. material thickness

First, I had to run test cuts on the Epilog Pro Fusion laser cutter before proceeding to cut most of the wood I had for the year, to ensure that the settings I had worked as intended.

Test cuts using 0.5 in. x 0.5 in. squares

After creating the file, I uploaded the vector and raster patterns to Google Drive, transferred them to Adobe Illustrator, and ensured that each piece was aligned correctly on the wood before cutting. I used these settings with the Epilog Pro Fusion laser cutter:

• Vector cutting:
  • 55% speed
  • 42% power
  • 50% frequency
  • 0.004 in. kerf (more on that later)
• Raster engraving:
  • 100% speed
  • 50% power
  • 600 dpi resolution

Enjoy these shots of the Epilog Pro Fusion laser cutter in action from the Nikon camera!

In the end, I ended up with five open-ended boxes, each specifically intended for a future project I am working on for the rest of the course.

However, the boxes’ side panels ended up falling down easily, meaning I had to adjust my kerf for two sides for each box. I also had to use the Epilog M2 printer, as I had learned that the Fusion printer’s laser cuts at a slight angle, which is not ideal for making press-fit boxes.

So, I went back to the drawing board. I changed the kerf for the boxes to be 0.008 in. instead of 0.004 in., with the hope that the resulting modified boxes will have a tighter fit than before. Then, I imported some of the resulting side panels (two for each box) into Illustrator and sent the file over to the M2 printer. It took numerous attempts and dry runs to position the pieces in the correct location for the laser to cut them out, but I eventually succeeded.

Before assembling, I engraved my name and my EDES 210 section onto the long side pieces of the chess piece carriage.

Here are the specifications for the M2 printer:

• Vector cutting:
  • 38% speed
  • 100% power
  • 50% frequency
  • 5 cycles
• Raster engraving:
  • 100% speed
  • 100% power
  • 50% frequency
  • 600 dpi resolution

Using the Epilog M2 Laser Cutter

When I first assembled the new boxes, the side pieces definitely had a much tighter fit than before, and I was excited about that. I used a rubber mallet to secure all of the side pieces in place. Some damage to the outer surface occurred during the process of securing the side pieces, so I will take this into account for a future attempt.

I then used Fusion 360 to make 3D models of the carriages that will house the boxes and create the chassis, through which the wheels and axles will fit. I then printed the models out on the Prusa 3D printers using PLA plastic (with 15% gyroid infill and organic support material) and, once they were finished, connected them together end to end, as shown in the bottom image below.

One of the carriage models in the Bambu slicing software! (Taken with phone camera)

The carriage that will have one of the laser-cut boxes on top.

All 5 carriages connected together!

One of the carriages (the one for the CNC milling project) didn’t have holes where the axles were supposed to go, so I had to drill a 1/4-inch-diameter hole in the carriage. It took a while, especially since I had to drill in two sides because the drill bit doesn’t go through the carriage entirely.

For each axle, I used a 0.25-in. diameter wooden dowel, which I cut to size for each carriage using a band saw, taking into account the thickness of the wheel. The result was 5 pairs of dowels, each of a different length depending on the carriage into which they would be inserted.

The dowel in which I cut the axles from.

I also modeled and printed caps made of TPU plastic (with 15% gyroid infill and organic support material) that fit snugly on the ends of each axle, preventing the wheels from falling out. For all but one carriage, the caps fit within a 0.05-inch clearance (i.e., the tube portion where the dowel slides in is 0.05 inches tall). For the CNC milling carriage, the caps had a 0.125-inch clearance to account for the dowels having a tighter fit in that specific carriage than the others. After printing the caps, I used super glue to attach the caps to the dowel axles.

The TPU plastic caps for one of the carriages.

For the wheels, I laser-cut 1.1-in. diameter wheels (4 x 5 = 20 wheels in total) with a 0.23-in. diameter hole at the center of each wheel to ensure a snug fit in the dowels. However, the wheels spun freely when I put them on the dowels, so I used the caps to ensure that they don’t fall out.

The carriage train with wheels and without the TPU caps.

After assembling everything together, the project train carriage is complete! I am very proud of how this project turned out, as it was an exercise in creativity that allowed me to achieve more than just a wooden laser-cut box, but a toy and a display that I can enjoy. I also believe that this is one of my best projects to date, despite the many adjustments I had to make along the way.

Note that I used my phone camera to take the above three pictures since I had to return the Nikon camera. They still look great.

Some details need improvement for a future attempt. First, as mentioned earlier, even though I used the recommended specifications for both the M2 and the Pro laser cutters, removing the new pieces from the M2 proved quite difficult, resulting in some damage to the initial plywood and requiring me to sand down the side wall pieces. As a result, I would need another cycle or two to the vector cutting specifications in a future attempt to ensure that the laser went through the wood. I would also need more test cuts (particularly for just a couple of side walls before cutting the whole thing) to adjust the fit as needed. Additionally, I do recognize that I kept some of the loose side wall pieces, so some of the walls are still loose. In a future attempt, I would replace one of the loose walls with one of the walls cut with a 0.008-in. kerf to ensure a tighter press fit on the walls. I would also reduce the diameter of the wheel holes to provide a more secure fit with the dowels.

• 1 x 24 in. x 24 in. sheet of 1/4-in. thick plywood (source: here) = $7.28
• 3D-printed PLA plastic (source: from Bambu slicing software based on 3D files) = $2.12 + $3.69 + $3.48 + $2.42 + $1.93 = $13.64
• 3D-printed TPU plastic (source: from Prusa slicing software based on 3D files) = $0.77

• Considering that $10 is a reasonable wage and that I spent about 7 hours working on this project: $10 per hour x 7 hours = $70
  • Note that assembly was still minimal, as I had to press-fit the new side pieces.

• $7.28 + $13.64 + $0.77 + $70 = $91.69

This project’s got everything, from laser cutting to 3D printing and using power tools. It somehow turned into a cumulative project of sorts…

BONUS POST!

Before I even made the box carriage train, I laser-cut my own name label for my crate. It consists of two of my college logos, a sky view of my hometown (Miami), and some icons associated with my activities at Rice (i.e., Rice Lions and affiliated clubs). Because the wood from which I cut the label was warped, I had to use a couple of clamps to help me glue the label to the crate using a hot glue gun. I’m proud of how the label turned out, and it’s a great addition to my crate.

The photo below was also taken by the same Nikon Z5 camera I used for my project photos.