Spaghetti wires! My industrial electronics learnings (MFINDLX & LBYMF3E)

TARGET AUDIENCE: Students, Academics, Industry Professionals, Employers, and Tech Enthusiasts

Note: Taglish

OVERVIEW: The understanding of pneumatic systems is salient to the understanding of the automation being done in manufacturing plants. It is that intention that the course and lab below provides us students (ako!), the oppurtunity to train ourselves under programmable logic controllers and the designing of electro-pneumatic systems!

LECTURE:

The lecture class was, frankly, boring. The calculations for it consist of me determining the logic function as well as the flow of air on end output from given inputs (wow /s) 😅. This may include providing the motion-step diagram, finding out the logic truth tables and lastly, obtain its plc ladder logic diagram. All of this was handwritten and handdrawn in the paper. I still remember doing the calculations one time in Jollibee Malibay since I was not able to make it in campus haha (sumilong ako sa ulan)

Aside from the gas laws and determination of pressure for safety, I think I got sidetrack on the laboratory since it was more practical. Overall there are many valves (especially its symbols) to consider and we had to memorize it. When I was looking at the exam paper, I just imagine what is the suitable pneumatic components to deliver the task given!

For the practical, my pair (si Nic) and we solved two automation problems I worked on two automation problems — a Metal Strip Bending Tool and a Cleaning Bath System. Both required designing electro-pneumatic circuits and simulating them with PLC ladder logic. To solve these, I provided the following components and solution below. You may also check out the video demonstration that I have below and our report.

COMPONENTS USED:

• Cylinders (Actuators)
  • Single-Acting Cylinder (SAC): Uses air pressure for forward stroke, spring for return.
    • Used in Cleaning Bath for simple forward/back motion.
  • Double-Acting Cylinder (DAC): Uses air pressure for both extension and retraction.
    • Used in both Bending Tool and Cleaning Bath for controlled motion in both directions.
  • Key Concept: Selection depends on whether the motion requires force in one or both directions.
• Directional Control Valves (DCVs)
  • 3/2 Valve: Three ports, two positions — commonly paired with single-acting cylinders.
  • 5/2 Valve: Five ports, two positions — essential for controlling double-acting cylinders.
  • Shuttle & Check Valves: Ensure correct air routing, allow manual/electrical actuation.
  • Key Concept: Correct valve selection enables precise cylinder control and sequencing.
• Sensors & Switches
  • Limit Switches: Detect cylinder end positions (extended/retracted).
  • Optical/Proximity Sensors: Detect presence of workpiece (used in bending setup).
  • Pressure Sensors: Provide feedback for safety and automatic retraction.
  • Key Concept: Sensors convert mechanical positions into electrical signals for PLC inputs.
• Electro-Pneumatics
  • Integration of relays, solenoids, and electrical signals to control valve actuation.
  • Combines the speed and power of pneumatics with the logic of electrical control.
  • Key Concept: Electro-pneumatic systems bridge physical actuation with programmable control.
• PLC Ladder Logic
  • Ladder diagrams used to sequence operations of multiple cylinders.
  • In Bending Tool: Three cylinders had to operate in sequence (clamp → bend → release).
  • In Cleaning Bath: Sequenced forward/back motions with gradual timing.
  • Key Concept: PLCs ensure safe, repeatable, and automated sequencing of pneumatic systems.
• Timing & Sequencing
  • Delay timers hold cylinder positions before the next step.
  • Counters ensure repetitive actions stop after a set cycle (e.g., 5 dips in a bath).
  • Key Concept: Time-dependent motion control is vital for automation consistency.

By combining mechanical actuation + electrical control + PLC sequencing, even complex tasks like bending tools and automated dipping baths can be executed reliably. These exercises mirror real-world industrial automation problems, where pneumatics are widely used for material handling, clamping, pressing, and cleaning processes.

Below is a consolidated document of the practical that I did for this lecture as well as the video demonstration that my pair and I did!

LABORATORY:

The laboratory class proided me practical skills on the use of pneumatic system to produce complex sequencing of cylinder actuation for a given output/intention. The use of sensors and safety controls were all considered in the activities that we did for this class.

I will show below the different exercises that we did along with learnings and insight that I find per exercise. I was able to properly document this experience kaya you will see the an accompanying video demonstation of explanation per activity. You may also see the final reports that we did for each of these exercises.

Pure Pneumatics

Exercise #1 – Water Precipitation

• Task: Calculate total water precipitated in a system using the dew point curve and absolute humidity at varying temperatures.
• Learning: Gained awareness of how moisture affects pneumatic systems—excess water can cause corrosion, leaks, or performance issues.
• Insight: In real factories, proper air drying and filtration is essential for reliable automation.

Exercise #2 – Pipe Diameter Calculation

• Task: Use nomograms to size pipes, considering valve lengths and total line length.
• Learning: Correct sizing ensures efficiency and avoids pressure drops.
• Insight: Small miscalculations can increase energy consumption—highlighting the importance of sustainable system design.

Exercise #3 – Single-Acting Cylinder Control

• Task: Build a circuit with a 3/2 valve and single-acting cylinder for feeding workpieces.
• Focus: Troubleshooting air leaks.
• Insight: Practical lesson in maintenance culture—air leaks are small inefficiencies that can cost industries heavily over time.

Exercise #4 – Sheet Metal Bending

• Task: Use a single-acting cylinder and push button to bend sheet metal into a U-shape.
• Insight: Demonstrated how pneumatics support low-cost, repeatable automation in small-scale production.

Exercise #5 – Double-Acting Cylinder Swivel

• Task: Design a swivel mechanism with double-acting cylinder + 3/2 valves.
• Learning: Secure tube connections are crucial for safety and system reliability.

Exercise #6 – Workpiece Removal and Tipping

• Task: Automated system with double-acting cylinder + 3/2 roller valve to remove/tip workpieces.
• Insight: Showed how pneumatics integrate with conveyors for material handling.

Exercise #7 – Box Movement to Assembly

• Task: Pneumatic circuit with 5/2 valve, shuttle valves, and double-acting cylinder to move boxes.
• Learning: Multiple actuation options (push button or pedal) taught redundancy and operator ergonomics.

Exercise #8 – Workpiece Clamping

• Task: Electro-pneumatic circuit with conditions:
  • Workpiece detection
  • Interlocks during drilling
  • Adjustable clamping speed
  • Fast declamping
• Insight: Learned about process safety and flexibility—core in Industry 4.0 smart workstations.

Exercise #9 – Gate Control

• Task: Double-acting cylinder controlled by four push buttons (two inside, two outside).
• Learning: Implemented adjustable opening/closing speeds for controlled motion.
• Insight: Similar logic is applied in safety gates in manufacturing plants.

Exercise #10 – Component Stamping

• Task: Electro-pneumatic stamping using two push buttons + pressure sensor for automatic return.
• Insight: Showed how sensor feedback ensures product quality and reduces errors.

Exercise #11 – Piston Holding and Retraction

• Task: Push button → forward stroke → piston held 10s → auto-return.
• Learning: Incorporated timing control.
• Insight: Pneumatic timers are crucial in synchronized production lines.

Exercise #12 – Acid Bath Dipping

• Task: Automated dipping with counter + limit switches, stops after 5 cycles.
• Insight: Showed how pneumatics + counters provide batch process automation.

Exercise #13 – Steel Bolt Pressing (Two-Hand Safety Control)

• Task: Two-hand valve system requiring simultaneous press within 0.5s.
• Insight: Essential safety mechanism—prevents workplace accidents during high-force pressing.

Exercise #14 – Workpiece Distribution to Conveyors

• Task: Distribute workpieces using two cylinders + four push buttons for sequence control.
• Learning: Importance of sequencing logic in complex automation.

Exercise #15 – Metal Strip Bending Tool

• Task: Electro-pneumatic system with 3 cylinders + limit switches + optical proximity sensors.
• Insight: Introduction to sensor integration for automated bending and quality assurance.

Exercise #16 – Box Lifting and Pushing

• Task: One cylinder lifts, another pushes to a second conveyor (sequence-dependent).
• Learning: Highlighted interdependent motions—a foundation for robotics and mechatronics.

Electro-Pneumatics

This is where the real fun (or torture) begins. The point where troubleshoorting is hard (teknik is to do continuity test for the wires) but completing the task is so rewarding! Electro-pneumatics now cover the use of electrical relays and corresponding circuits to determine the logic of the actuation and control. Down the line, we get to also do industrial programing instead so less wires, less trouble! Further elaboration of the exercises that we did can be seen below.

REFLECTION AND COURSE INSIGHTS:

Again, I always look back and ask myself, can I apply this to my current job/career? This time, it was more of a grey area for me. I want to do technical work when I’m out in the field (not a paper-pusher), and I always see this as a skill that I can use when I’m down in the trenches of the machine and troubleshooting it. Of course, here in the country, you will actually need NCII trainings and certificates to show to the employer that you are capable of the job and not simple the degree. Also the job stability and the lack of the need for people to do this type of work that is mainly outside MEM career choices, you’ll be suprised that covering this is really a setback. This is because we are touching already in the realm of electrical engineers and the extensive background and learnings that they have also done, cannot be matched with what we have currently. Heck, the course goes back and forth on mechanical and electrical engineering concepts!

It has its merits though, the world is constantly evolving and the concepts here are outdated. Many of the projects done now cover use of OPC-UA connection from PLC to the hardware as well as me CAN-BUS network operations for whole plant connection for IoT. This course provides a solid foundation whenever we will encounter this in the wild in either our robotic systems or mechatronics ones that are heavy-duty. Let me know your thoughts as well in the comments below!

PS. Shoutout kina Nic na tumulong sakin for the finals at si Adam for being a solid partner throughout the labs.