Problem Statement: What problem does the project solve?

Motivation: Why is this project important or useful?

Project Description: Provide a brief overview of the proposed project.

Email: jbouchard6@mail.valenciacollege.edu

Name: Adriano Mena Duque de Estrada

Email: amenaduquedeestra@mail.valenciacollege.edu

I'm not sure if we'll do the conveyor belt, or just the outputs lights...

Date: 06/08/2026 - 5:00 pm
Led by: Dr. Mayra Socarras and Dean Lara Sharp
Purpose: First meeting outlining an initial pass of the Senior Proposal

1. Scheduling Issues

   1. Some students raised concerns about the time switch.

   2. Proposed solution: move classes from face-to-face to Zoom.

   3. While the moving to zoom was an accepted measure, it didn't solve everyone's problems. Therefore, a poll will be sent to be completed this week to define the new date and time of the meetings.

2. This Week's Task

   1. Create a Padlet using the provided template: https://padlet.com/larasharp2002/eet4910-draft-template-nep8y6kfvvyrirce

   2. Write the problem statement

   3. Conduct research

   4. Start the systems document

   5. Identify possible constraints and challenges

   6. Begin drafting the project timeline

3. New Approach This Semester

   1. There won't be multiple proposals per group, just the one to be completed.

   2. Conduct a SWOT analysis (Strengths, Weaknesses, Opportunities, Threats) to determine that project.

   3. Post results on Padlet, or schedule an appointment with Sharp and Socarras.

   4. The professor will provide feedback asynchronously via padlet.

4. All Required Assets

   1. System-level diagram with interfaces

   2. System requirements (per IEEE standard)

   3. System specification (limitations/requirements for correct system performance)

   4. Web page

5. Key Deadlines

   1. First version of concept: June 29th

   2. Project proposal report: July 26th

   3. Project proposal presentation: July 31st

6. Other useful information

   1. Lara Sharp's office location: Building 9-140

   
   

• Wax bath temperature regulation is external — the system only interfaces with an already-heated bath; it does not control bath temperature, heating elements, or thermal sensors in this phase.

• The prototype operates on a benchtop-scale mock conveyor, not full industrial hardware (no full-length industrial belt).

• No vision system — piece detection and positioning rely entirely on TOF and/or ultrasonic sensors and fixed-position arm coordinates; no camera-based guidance.

• No multi-axis simultaneous motion — the arm executes sequential joint movements (not coordinated interpolated paths), which limits cycle speed.

• No wax bath level monitoring — bath depletion or overflow is not measured or flagged by the system.

• No safety interlocks for human proximity — the prototype is intended for unobstructed lab operation; no light curtains or safety PLCs (maybe add a detection system to it?)

• Single piece per cycle — the system processes one part at a time; no parallel or pipelined processing of multiple pieces.

• Fixed arm mounting — the arm base is stationary; it does not translate along more than a rail or gantry.

1. E18-D80NK IR Proximity Sensor with Arduino — Circuit Digest

https://circuitdigest.com/microcontroller-projects/interfacing-e18d80nk-ir-proximity-sensor-with-arduino

2. E18-D80NK Project on Instructables

https://www.instructables.com/Project-on-E18-D80NK-IR-Proximity-Sensor-With-Ardu/

3. TB6600 Stepper Motor Driver — RobotShop

https://www.robotshop.com/products/tb6600-stepper-motor-driver

4. TB6600 + Arduino + NEMA Motor Wiring Tutorial — YouTube

https://www.youtube.com/watch?v=nLV0fjUWI-g

5. DS3225MG 25KG Waterproof Digital Servo — DSPowerServo 

https://www.dspowerservo.com/high-speed-metal-gear-coreless-waterproof-digital-servo-ds3225-25kg-servo-product/

6. DS3225MG Review — YouTube 

https://www.youtube.com/watch?v=6Re_6vCxcgw

7. Pick and Place Robotic Arm — Instructables

https://www.instructables.com/Pick-and-Place-Robotic-Arm/

8. Robotic Arm for Automated Pick and Place Operations — IJRPR

https://ijrpr.com/uploads/V6ISSUE5/IJRPR44762.pdf

9. Pick and Place Robots: An In-Depth Guide — Wevolver

https://www.wevolver.com/article/pick-and-place-robots-an-in-depth-guide-to-their-functionality-and-applications

10. Robotics in Investment Casting: Uses and Benefits — Impro Precision

https://www.improprecision.com/robotics-in-investment-casting-uses-and-benefits/

11. Robotic Installation for Investment Casting Wax Assembly — Ecrimesa Group

https://ecrimesagroup.com/robotic-installation-for-investment-casting-wax-assembly/

12. Arduino PID Library — Brett Beauregard / GitHub 

13. Universal Robots UR3e Product Page

14. Epson T3 SCARA Robot

15. Yaskawa MotoMini

16. amazon.com/Aluminum-Extrusion-European-Standard-Anodized/dp/B08Y8LWW4R/ref=sr_1_4?crid=RD9IDPMKWNEW&dib=eyJ2IjoiMSJ9.WsUtEi2eRhuBYmbXiV6sBGacXMK5Ldadkbz9sLp1BWV5TwWJbHK-pIsa761OEQOGWf8Z7Gn5yIfMOXcPgJHliPQHbUKAgDIifqNf_xmCCQzv8IbXpeqC40HdwlHpvKCjDagFDM-DROm5B1D9Bj_b_iJHFom0KRcOdMLY1NtgoiAkRy3ztlCnMOxa6yCnkOFUZoGoNDAP2MWkndH3nNKct_EZlMKa4uzutWCUmysJdR23Bz-rkF2jmSRcDdu8XIixokHCg0z8LUJ91VL0FNkCx__3oIRJOGtT9cyuT7yTJhQ.UJlY2ZZzE3H_5X1RdUnBlwUlSYUO5UVjXuvjdZBf46M&dib_tag=se&keywords=2pcs+600mm+T+Slot+2020+Aluminum+Extrusion+European+Standard+Anodized+Linear+Rail+for+3D+Printer+Parts+and+CNC+DIY+Black%2823.6inch%29&nsdOptOutParam=true&qid=1782242300&s=industrial&sprefix=2pcs+600mm+t+slot+2020+aluminum+extrusion+european+standard+anodized+linear+rail+for+3d+printer+parts+and+cnc+diy+black+23.6inch+%2Cindustrial%2C109&sr=1-4

All components selected for commercial availability, low cost, and university lab compatibility.

Mechanical Structure

• Robotic Arm: 4-DOF desktop robotic arm frame (e.g., 3D-printed or acrylic kit)

  • DOF 1 — Base rotation (Z-axis, horizontal swing): positions arm between input conveyor, wax bath, and output conveyor

  • DOF 2 — Shoulder joint (vertical lift): lifts and lowers arm

  • DOF 3 — Elbow joint (reach extension): extends arm over conveyor or bath

  • DOF 4 — Gripper open/close: actuates end effector

• 4pcs 600mm T Slot 2020 Aluminum Extrusion European Standard Anodized Linear Rail for 3D Printer Parts and CNC DIY Black(23.6inch)

Actuation

• Shoulder & Elbow Joints (dip axis): NEMA 17 Stepper Motor (e.g., 17HS4401, 1.7A, 40 Ncm holding torque)

  • Used for the vertical dip axis where precise depth control is critical

  • Step resolution: 1.8°/step (200 steps/rev); microstepped to 1/16 via driver for finer depth increments

  • Each step at 1/16 microstepping ≈ 0.001° of joint rotation → sub-mm depth resolution at typical arm link lengths

  • TB6600 stepper driver — 9–40 V input, up to 4 A output current, DIP-switch microstepping selection; one driver per stepper axis

• Base Rotation Joint: MG996R Metal Gear Servo Motor

  • Torque: 9.4 kg·cm (4.8V) — sufficient for horizontal swing of arm + piece

  • Speed: 0.17 s/60°

  • PWM control via Arduino

• Gripper: DS3225MG 25 kg·cm Waterproof Digital Servo

  • Waterproof rating — critical for wax bath proximity environment (splash, vapor, drips)

  • Metal gear, coreless motor — high durability for repetitive open/close cycles

  • Operating voltage: 4.8–6.8 V; Stall torque: 25 kg·cm at 6.8 V

  • PWM control: 500–2500 µs pulse width, 50–330 Hz

Sensing

• Piece Detection (Input Conveyor): E18-D80NK IR Proximity Sensor

  • Modulated IR output — immune to ambient light and sunlight interference

  • Adjustable detection range: 3–80 cm (set via trim screw)

  • Output: NPN open-collector digital (active LOW on detection)

  • Supply: 5 V DC; interface directly to Arduino digital pin with INPUT_PULLUP

• Piece Detection (Output Conveyor / Placement Confirm): Second E18-D80NK — confirms successful placement and signals conveyor advance

• Dip Depth Feedback: Stepper step count (primary) — depth is derived from step count with a known steps-per-mm conversion; no additional encoder required for PoC

  • Optional upgrade: AS5600 magnetic rotary encoder on shoulder joint shaft for closed-loop position verification (12-bit, I2C, 0.0879°/LSB resolution)

• Gripper State: Microswitch (e.g., Omron SS-5GL) — mounted inside gripper jaw to confirm full close contact with piece; prevents false "pick success" when gripper closes on empty conveyor (fault R12)

Control

• Main Controller: Arduino Mega 2560

  • Selected over Nano/Uno for additional UART ports (logging + display), more digital I/O (multiple sensors, drivers, indicators), and hardware timer channels for servo PWM

  • Runs the main state machine: IDLE → DETECT → PICK → TRANSPORT → DIP → HOLD → RETRIEVE → DRIP → PLACE → LOG → IDLE

  • PID loop executes in software (Arduino PID Library by Brett Beauregard) at 50 Hz update rate, regulating dip descent speed based on step count vs. target depth profile

  • Serial output at 115200 baud for debugging

• Servo Driver: PCA9685 16-Channel PWM Driver (I2C, 0x40)

  • Offloads PWM generation for MG996R (base) and DS3225MG (gripper) from Arduino

  • 12-bit resolution per channel

• Stepper Drivers: 2× TB6600

  • One per stepper (shoulder, elbow)

  • DIR/STEP/EN signals from Arduino Mega digital pins

  • Input voltage: 12–24 V DC from bench supply

Data Logging & Display

• SD Card Module (SPI) — logs cycle data (cycle #, dip depth, hold time, dip speed, fault code) to a .CSV file on a standard microSD card

  • SPI interface: CS, MOSI, MISO, SCK → Arduino Mega SPI pins

• 0.96" OLED Display (SSD1306, I2C, 0x3C) — shows current state, cycle count, last dip parameters, and active fault codes

• Status LEDs (×3):

  • Green — system READY / cycle running normally

  • Yellow — DRIP / WAIT state

  • Red — FAULT condition active

Power Supply

• 12V / 5A DC bench power supply — powers stepper drivers (12V rail) and servos via LM2596 buck converter (5V/3A regulated output)

• LM2596 Buck Converter Module — steps 12V down to 5–6V for servo and logic power

Communication paths:

• E18-D80NK sensors → Arduino Mega (digital GPIO, NPN active-LOW)

• Gripper microswitch → Arduino Mega (digital GPIO)

• Arduino Mega → 2× TB6600 (DIR + STEP + EN signals, digital GPIO)

• TB6600 → NEMA 17 steppers (bipolar stepper phases A+/A−/B+/B−)

• Arduino Mega ↔ PCA9685 (I2C, 0x40)

• PCA9685 → MG996R (PWM) + DS3225MG (PWM)

• Arduino Mega ↔ SSD1306 OLED (I2C, 0x3C)

• Arduino Mega ↔ SD card module (SPI)

• Arduino Mega → Status LEDs (GPIO digital out through resistors)

Limit $500

- The system shall move only in two directions: horizontal and vertical.

- (TBD) The claw of the system shall tolerate high temperatures and wax-resistant.

# Dipping process

- The system shall detect incoming pieces on the input conveyor using a time of flight sensor.

- When a piece is detected, the system shall position itself above the piece, pick the piece with a servo-actuated gripper.

- When the piece is picked, the system shall move the piece horizontally above the wax bath.

- When the piece is moved above the wax bath, the system shall execute a dip sequence into the wax bath at a programmed depth and hold time.

- After the dip sequence, the system shall move the piece to the output conveyor and wait for the next piece.

# Safety measures

- When the E-stop is pressed, the system shall get to a home position before de-energizing actuator power. If this cannot be confirmed within 10 seconds or less then all power shall be cut regardless and the fault shall be logged.

# Communications

- The system shall communicate its current state and any errors or faults to the operator via:

- Safe default: Serial structured communication

- Safe Extension option: MQTT

- Full Extension option: Modbus TCP

- (Optional) The system shall provide a dashboard which will display the current state, and any errors or faults to the operator

• It's 3.3v and supports 1-wire mode or SPI, which could reduce the amount of pins used.

• Operational temp: -40°C to 90°C

• Blind zone of 2-3cm

• its recommended and most reliable operating range is between 2 cm and 200-300 cm (2 to 3 meters)

• A lot of this will be clearer once we establish the scope, and therefore the strength of the servos, and with that the servos.

• The Ethernet adapter is still a TBD. It depends on how communications will be performed.

• Servo controllers may be ommitted if the servos already include the controller (common for smaller servos).

• E-stop is not drawn yet, as power requirements will also come once scope is fully defined.

Proper Fail-Safe Solutions

Option 1 — Spring-loaded jaws (best for your case)

Design the jaw so a spring naturally closes it. The motor/stepper only works to open the jaw. When power cuts, the spring snaps it shut.

• Zero power needed to hold grip

• Instant fail-safe closure on any power loss

• Simple mechanical design — just a torsion or compression spring in the jaw linkage

• The stepper/servo only fights against the spring to open

• Very common in industrial grippers for exactly this reason

Option 2 — Electromagnetic brake (NEMA 17/23 with brake)

You can buy NEMA steppers with a built-in spring-engaged electromagnetic brake — the brake is held OPEN by power, and springs CLOSED when power cuts. Same fail-safe principle.

• NEMA 23 with brake: ~$35–60

• Automatically locks the shaft on power loss

• Works without any software or controller intervention

Option 3 — Worm gear drive

A worm gear is self-locking — the load cannot back-drive it. Once the jaw closes, it physically cannot open without the motor turning it, even with zero power.

• Add a worm gear between the motor and jaw mechanism

• Any small motor works since the worm gear multiplies torque and self-locks

• No springs needed, no brake needed

• Downside: slower open/close speed

A lead screw operates on sliding friction, converting rotational torque into linear force via matching threads (like an optimized nut and bolt).

• Mechanical Advantage: Extremely High. The shallow angle of the threads acts as a continuous wedge or ramp. A small amount of motor torque is multiplied into a massive linear lifting force.

• Speed: Low. Because it only advances by its lead distance (e.g., $2\text{ mm}$ or $8\text{ mm}$) per full motor revolution, the motor must spin at high RPMs to achieve fast travel.

• Length Limits: Short (Under 1 Meter). Over long spans, a thin lead screw will sag under its own weight and begin to wobble violently at high RPMs—a destructive phenomenon called screw whip.

• Self-Locking: Yes (if single-start like a Tr8x2). Friction prevents back-driving.

• Best Fit for Your Gantry: Your Vertical Z-Axis (30 cm). It perfectly handles the heavy 10 kg vertical lifting load without skipping steps, easily fits within the short travel length, and natively locks in place when power is cut.

  
  

2. Timing Belt Drive

A timing belt drive uses a flexible, reinforced rubber loop wrapped around a geared pulley on the motor shaft and an idler pulley at the far end.

• Mechanical Advantage: Low. One turn of a typical 20-tooth GT2 pulley moves the axis $40\text{ mm}$. This large distance means the motor acts against a long lever arm, drastically reducing its linear pushing force.

• Speed: Extremely High. Because of the large travel distance per revolution, a belt drive can easily achieve blazing travel speeds (over $500\text{ mm/s}$) at very low motor RPMs.

• Length Limits: Moderate (Up to 2-3 Meters). Belts span long distances easily, but if the belt is too narrow, it acts like a giant rubber band—stretching slightly under high loads, which causes positioning errors and structural "bounciness."

• Self-Locking: No. It is incredibly smooth and back-drives instantly under weight.

• Best Fit for Your Gantry: Your Horizontal X/Y Axis (1 Meter) if you use a heavy-duty, steel-reinforced, wide belt (9mm or 15mm width) paired with a high-torque NEMA 23 motor. It provides fast, quiet, and smooth travel across your 1-meter span.

  
  

3. Rack and Pinion

A rack and pinion turns rotational motion into linear motion by running a circular gear (the pinion) directly along a long, flat track of gear teeth (the rack).

• Mechanical Advantage: Low to Moderate. Similar to a belt drive, one turn of a standard pinion moves the carriage a large distance (typically $60\text{ mm}+$ per turn), sacrificing torque for speed. However, you can couple the motor to a small gearbox reduction to regain that lost torque.

• Speed: High. It offers excellent high-speed travel capabilities across massive distances.

• Length Limits: Infinite. Unlike screws that whip or belts that stretch, racks can be bolted end-to-end indefinitely. The rigidity of a steel rack remains identical whether the axis is 1 meter or 10 meters long.

• Self-Locking: No. A heavy gantry can easily back-drive a standard pinion gear when the motor is disabled.

• Best Fit for Your Gantry: Your Horizontal X/Y Axis (1 Meter). Because your horizontal carriage must move a combined weight of around 13–14 kg (the vertical motor, rails, and the 10 kg object), a rack and pinion offers zero-stretch mechanical rigidity across that 1-meter span.

or

https://www.amazon.com/Sydien-Pillow-Block-Flange-Bearing/dp/B07C5MTB5X

$10 each

The system shall use a two-axis stepper-driven motion system to pick up parts, dip them in the wax bath, and place them at the output station, achieving positional accuracy within ±1 cm on both axes. This will be confirmed by commanding each axis to a known target and measuring the offset with a ruler. NEMA 23 motors paired with compatible stepper drivers provide enough torque and control resolution to meet this accuracy target given the payload and travel range involved. Reliable, accurate motion is essential to completing the pick-dip-place cycle without dropping or misplacing parts, and this objective shall be completed and validated before final system integration testing begins.

Objective 2: Control and Sensing Reliability

The system shall use a microcontroller-based state machine that reads ultrasonic and limit switch inputs to safely sequence motor and end-effector actions, with correct part detection at the input station and correct motion stop at each axis limit confirmed through direct testing of each sensor. The selected microcontroller has sufficient GPIO, processing speed, and I/O compatibility to handle all required sensors and outputs, making this objective achievable within the current hardware design. Reliable sensing and state control are necessary to prevent collisions, missed parts, and unsafe operation, and this objective shall be completed, with sensor integration and state machine testing finished, before end-effector integration begins.

Objective 3: Safety and Communication

The system shall include a hardware emergency stop and an Ethernet-based Modbus TCP reporting system that communicates system state, position, and faults, with the E-stop confirmed to cut power immediately when actuated and require manual reset, and all state transitions and faults confirmed to appear correctly in Modbus TCP output during a full operating cycle. A normally-closed E-stop rated for peak current and an SPI-compatible Ethernet module both integrate directly with the existing power and control architecture, making this objective achievable without major redesign. Operator safety and system visibility are required for safe operation and effective troubleshooting, and this objective shall be validated during the final safety and communications review before project completion.