Laser Drawing Machine

✨Draw phosphorescent light trails with a machine designed and built completely from scratch!

The story: In between studying breaks during midterm week, my friend Brett and I designed and built this machine that utilizes a laser and mirror system to draw luminescent light trails, controllable via a 3D printed joystick. The main goal was to use drawing techniques and materials people wouldn’t typically associate with drawing while instilling a sense of intrigue in the user.

We hope you enjoy it as much as we had fun designing and building it!

We’re two broke students so we largely turned to finding scrap pieces and discarded wood around our school and all tools were from our school's makerspace. We also didn't have access to many metal materials (gears, rack and pinion, dowel, etc.) so we made them ourselves from laser cut wood. For the pieces we couldn’t find, we bought them on amazon for a total of $19.50.

Note: this project requires a laser, remember not to look at it directly in the eyes!

Materials:

• 1/4 in Plywood (x2)
• 1/8 in Plywood (x1)
• Wood Glue (thin layer)
• 1/2 in Wooden Dowel (x1)
• 1/2 in Mirror (x1)
• 1/4 in diameter 2 in long Brass pipe (x1)
• 1/4 in diameter 2 in long Copper pipe (x2)
• 1/4 in diameter 1.5 in long Brass pipe (x3)
• 1/2 in O.D. 1/4 in I.D. Ball Bearings (x6)
• 405 nm laser Diode (x1)
• Arduino (x1)
• 24 AWG 6ft wire (x1)
• Phosphorescent powder (x1)
• Power Jack 120 VAC to 9 V power adapter (x1)
• Rubber band (x1)
• Joystick 2-axis analog (x1)
• L298N Motor Driver (x1)
• 2.5 mm DC Jack (x1)

Tools:

• Laser cutter
• Sandpaper
• Saw
• Hot Glue Gun
• Dead Blow Hammer
• Soldering Iron
• Drill
• 3D Printer
• Dremel

Attached are the two illustrator files for all the wooden pieces that need to be laser-cut and their names correspond to the type of wood they should be cut out on (1/4 inch v. 1/8 inch plywood). I also attached images of the files. There are actually more lock washers than needed but they occasionally break so it's always nice to have some extras.

All lines should be cut, not engraved. Once they're cut out, move on to the next step!

Above are images of how the pieces come together as well as a behind the scenes video. The construction for this step is divided into first constructing the pieces from the previous 1/4 inch illustrator file and then the 1/8 inch illustrator file.

1/4 inch section---

Base: Push the dowels through the corner of the base plates and push the lock washers through the ends of the dowel to keep the baseplates in place. This base provides a space for the arduino to stay semi-hidden while providing support for the artboard canvas.

Roller Bearing Support: Glue the roller bearing support onto the 1/8 inch motor housing roof face

Bearing Assembly: The top rack is held in place and moved by a triangular arrangement of roller bearings that keep it from rotating while preserving smooth translational motion. An image of how the roller bearings look is provided above. The diagrams depict how the roller bearings interact with the rack and where they're placed on the machine. Place these through the holes of the roller bearing support you glued onto the motor housing roof

Support Beams: Labeled as "these ensure the rack doesn't fly off" in the quarter-inch file, these support beams reduce wobble by adding to the rigidity of the rack and prevent over-enthusiastic users from sending pieces flying off of the machine or shattering the glass mirror! We used wood glue to attach them to the top rack since it will need to be sturdy.

1/8 inch section---

Bottom Rack: The bottom rack is the shorter rack with the hole. This hole allows you to feed the arduino wires from under the slit of the top baseplate and into the motor housing, so the wires can reach the motor even when the bottom rack is moving.

Top Rack and pinion: The top rack is the other rack (the longer one). An image of what the pinion (one of the giant gears) structure looks like and how it works is provided in the picture with the lock washers.

The rest of the 1/8 inch section (the motor-related pieces) is explained in the next step... 👇

Next, we needed to design the motor mounts and motors to make it move. There are two motors, one for moving in the x-axis and the other for moving in the y-axis.

Making Two Motor Mounts: We sandwiched the middle motor mount pieces (the ones with the hexagon holes) between the other two which contain holes for the bolts to fit through. We then attached each motor to each motor mount using screws. Gluing the mount and motor to any surface now allowed us to easily install and remove our motors using only hex wrench. To transition from motor to gear, we used a 3D printed shaft collar to interface with the dowel-shafted gear.

Motor Housing: The motor housing pieces make a box-shaped housing for the motor. The rectangles with holes in them are the top and bottom pieces (the one with several holes is the top). The rest of the motor housing box is composed of the sides which fit together using their grooves + ridges. Glue all the pieces together at the edges except one face since you still need to put the motor inside and it's easier to do so from the side than from above.

Controlling the Motor: To control the motors we used a joystick, Arduino, and separate motor driver to power the motors. Everything runs off a single 9-volt DC jack. To achieve the desired motion, we had to adjust the strength of the PWM signal so that it was enough torque to overcome friction in the gear while keeping it from moving too quickly. The next step describes the Arduino configuration and code... 👇

This is the Arduino code to control the positioning of the laser using the joystick as input. The code is written so that each direction of the joystick controls one of the motors (the motor controlling the x-axis and the motor controlling the y-axis). This allows for the machine to draw curves and diagonals whenever the joystick position is away from the horizontal/vertical axis.

We chose to 3D print a joystick case in PLA so it would feel comfortable and natural for the user to hold and operate (although it can still function correctly without a case).

Essentially, it is two halves of an oval casing with a hole on one side. We put the controller stick inside so when the casing is put together, it fits through the hole for the user to interact with. The wires extend out the back of the other side of the casing and to the arduino.

Paint the artboard canvas with the phosphorescent powder and let it dry while you work on the next steps.

🎨Make sure to keep it in a very sanitary environment, the first time we applied the powder, dust and sawdust got stuck. It's also easier to mix the powder with paint so it sticks easily.

Why isn’t the laser just pointing straight down from the end of the top rack?

Brett and I quickly realized putting the laser directly over the drawing board at the end of the rack weighed the end of the rack down which limited its range of motion. Instead, we decided to take inspiration from the design of a laser cutter.
The solution: By putting a mirror at the end of the rack with a 45-degree tilt, we could ensure the beam would point directly perpendicular with the surface without adding weight to the end!

The Laser: Carefully mount the laser and mirror. Feed the laser wires through one hole on the top of the motor housing roof to connect to the battery. Loop rubber bands through the other hole of the motor housing roof to secure the laser in place.

The Mirror: The mirror should be angled at a 45-degree angle using the triangular quarter-inch pieces. By mounting the laser parallel with the ground, the laser beam should reflect off of the mirror and hit the ground directly below, even if the rack moves.

After testing to make sure it worked properly, we glued on the last face of the motor housing. To increase the machine’s visual appeal, we attached lock washers at the bottom of the dowels. It also had a slight functional purpose as well since these washers acted as "feet" for the machine (instead of the whole base touching the ground) which made it easier to move the whole machine on a table. We then gave the product a final polish by sanding all exposed wood.

Reflection: We had a great time designing this machine and an even better time playing with it. Ironically, the most complicated parts of the design seemed to give us the least trouble, while the simplest parts gave us the most. If we were to do this project again, we would experiment more with friction-reducing materials on the moving parts.

We hope that people enjoy this device as much as we do and that it inspires them to create even better versions of this machine in the future.

-Best,

Justin and Brett