How Cal Maritime Uses Our Desktop CNC Machines to Teach Electronics

One of only seven degree-granting maritime academies in the U.S., California State University Maritime Academy (Cal Maritime) is also the only one on the West Coast. They offer degrees in three branches of engineering: Facilities Engineering Technology, Marine Engineering Technology, and Mechanical Engineering.

Two years ago, Cal Maritime acquired a Bantam Tools Desktop PCB Milling Machine, and it’s currently being used by students in two courses: ET 370 Electronics and ET 350 Electro-Mechanical Machinery. They’re also in the process of renovating one of the classrooms into a makerspace/innovation lab and plan to add another Bantam Tools Desktop PCB Milling Machine to the mix.

At the end of each ET 370 course, students host a Final Project Fair to show off their innovations, on average between 15 to 18 projects. The latest iteration of the fair took place last month. We spoke with Associate Professor Dr. Evan Chang-Siu to learn more.

1. How long had students worked on the projects?

The students only have one semester to work on this project. What I'm proud of is that the students will have only taken basic circuits before the class but will have had no programming experience. For example, the first lab is to turn on an LED using an Arduino.

By the end of the semester, the students will be utilizing transistors, steppers, servos, LEDs, different sensors, and programming their own custom applications. It takes an incredible amount of work and dedication, but watching the students progress and witnessing the culmination of working projects at the fair makes it all worth it.  

2. What were the prompts/criteria for the projects? 

Each group must utilize an Arduino for computation, take in sensor data, and actuate some output, whether it be LEDs or motors. This way, students are forced to combine software concepts and electronics, which reinforces the theories taught during lectures, in a practical setting. The projects are open for the students to choose, and I require that they meet with me to discuss scope, intellectual merit, and feasibility. 

3. Did students work in teams?

The students do work in groups of two or three, not one and not four or more. The reason for the minimum size is so that teamwork is required, to learn the challenges of working with others. Also, teams are maxed at three to ensure engagement.

The teams are also randomly selected to simulate on-the-job situations, where they'll be forced to work with people whose styles may or may not fit their own. It also enables students to connect with peer groups that they normally would not have, and it does bring the class together.

4. What were some of the standout projects?

The students voted for their top three.

The first place project was a reaction wheel inverted pendulum where the students balanced an unstable pendulum using a flywheel. The angle of the flywheel was sensed by an IMU, and the reaction wheel fought against the instability. 

The second place project was a servo-driven 3D-printed hand driven by a glove outfitted with flex sensors.

The third place was an automated drink dispenser called the Tiki Train. This allowed a user to select a desired drink mix and the system used a stepper motor to linearly move a cup to a desired servo-driven dispenser. 

However, one project that I personally was impressed with was the word clock. The students created a matrix of LEDs and lasercut a matrix of letters. When specific LEDs lit up, different words would appear corresponding to the time, e.g., "It's half past one o'clock." One touch that made the project special was that they included the words, "Hi Dr Chang Siu." The word clock is now in my office as a proud display. 

5. What has the Bantam Tools Desktop PCB Milling Machine enabled students to do that they may not have been able to previously?

The Bantam Tools Desktop PCB Milling Machine has allowed the students to create much more reliable, compact, and professional-looking circuit boards. For example, one of the projects was an LED and EL wire helmet that lit up different segments based on the frequency content of the music. While the original circuit worked, it took up three and a half breadboards with wires everywhere. With the Bantam Tools Desktop PCB Milling Machine, the circuits were heavily condensed into two stackable PCBs and could be easily mounted to the back of the helmet.

I really appreciate the workflow efficiency built into the Bantam Tools Desktop Milling Machine Software. It allows me to go from and EAGLE CAD file directly to Bantam Tools Desktop Milling Machine Software, which creates its own toolpaths. I also really love the auto-z and bracket-location features and the fact that all drilled holes only require one flat end mill. This saves a lot of time not having to manually locate and switch out tools.

6. What other types of things do students use the Bantam Tools Desktop PCB Milling Machine for?

Cal Maritime competes in the DOE-sponsored Collegiate Wind Competition. The Bantam Tools Desktop PCB Milling Machine has also been used to design the board that contained the buck/boost converter and rectifier to take the three-phase power generated by the wind turbine and trickle-charge a battery. You can see our team here. 

 Thanks Dr. Chang Siu and Cal Maritime for sharing with us!