FabAcademy 2023

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Electronics production ​

This week I have designed and manufactured an Electric Board. I have milled it in a small Benchtop CNC Roland, soldering the circuits, and running the programs I develop for it.
Hero shots of my first PCB.

Learn and test our desktop CNC Roland DMX40 - as group work ​

The Modela MDX-40 3D Milling Machine is a versatile and precise desktop milling machine designed for a variety of applications, including prototyping, jewelry making, and educational purposes. It features a high-speed spindle, a robust Z-axis, and compatibility with various software, making it an excellent tool for detailed and intricate work.

Safety first ​

When using the Modela MDX-40 3D Milling Machine, it's important to follow these safety precautions to ensure safe operation:

  • Wear Safety Glasses: Always wear safety glasses to protect your eyes from flying debris.
  • Use Dust Mask: If the operation is dusty, wear a dust mask to avoid inhaling particles.
  • Secure Workpiece: Use clamps or a vise to hold the workpiece securely in place.
  • Avoid Overreaching: Keep proper footing and balance at all times to avoid accidents.
  • Maintain Tools: Keep tools sharp and in good condition to ensure efficient and safe operation.
  • Proper Grounding: Ensure the machine is properly grounded to reduce the risk of electric shock.
  • Follow Manufacturer's Instructions: Always read and follow the manufacturer's instructions and safety guidelines.

Equipment usage ​

Clamping the Workpiece ​

  • Clean the clamping platform of any impurities.
  • Secure the workpiece using double-sided tape.

Setting the Origin ​

  • Turn on the machine, press ENTER to return to the initial origin.
  • Use the direction keys to move above the workpiece. Set the machining origin by moving the x, y, z axes to the desired origin, press ENTER twice to complete the origin setting.

Machine Usage Notes ​

  • The maximum machining range of the machine is 305 mm [X] × 230 mm [Y] × 30 mm [Z].
  • Clean the machining platform to prevent height differences.
  • After using the machine, press the emergency stop and turn off the power.
  • The spindle speed ranges from 5000 to 15000 RPM.
  • When machining parts, set the appropriate parameters according to the material and speed; otherwise, the tool may break.

Software for Roland ​

The software used for our Roland is MODELA Player 4.

Using the Machining Software ​

  • Open the 3D data of the part to be machined.
  • Supported 3D data formats.
  • Adjust the orientation for machining.
  • Set the margin and machining area for the workpiece.
  • Add the machining tool and set the diameter of the tool to be used.
  • Configure the parameters for the machining tool.
  • Set the machining process.

Problems & improvements found when testing the machine ​

Problems ​

  • When machining circuit boards, tools with a diameter less than 0.5 mm are prone to breaking.
  • Parts cannot be fully cut off after machining.
  • The surface of machined parts is rough.
  • Incorrect origin setting leads to parts being machined with one side smaller.

Optimization Solutions ​

  • When machining circuit boards, reduce the spindle speed and decrease the cutting amount.
  • If the surface of machined parts is rough, increase the spindle speed and decrease the cutting amount for finishing.
- When setting the machining origin, set the margin and machining area according to the required dimensions.

Design of the Broad with Fusion 360 ​

This week we still use Fusion for PCB design since it offers several advantages:

  • Integration: Fusion 360 seamlessly integrates with other CAD and PCB design tools, making it easy to import and export designs. This allows for a smooth workflow between mechanical and electrical design1.
  • Collaboration: As a cloud-based tool, Fusion 360 enables multiple users to work on the same project simultaneously. This makes it easy to collaborate with team members and clients, ensuring everyone is up-to-date with the latest design changes1.
  • Simulation: Fusion 360 includes simulation tools that allow you to test your PCB design virtually before manufacturing. This helps identify potential issues early on, saving time and money1.
  • True 3D Design: Fusion 360 offers a true 3D PCB editor, allowing designers to work with designs in a 3D realm. This means you can make changes to the 3D components or board shape and see how it affects the PCB layout2.
  • Unified Environment: Fusion 360 unifies ECAD (electrical) and MCAD (mechanical) workflows, providing a comprehensive and connected design experience. This eliminates the need for file exchanges or third-party integrations2

Design process ​

First of all do a schematic design same as week6.

Run design rule check process, the settings should be relate to the Roland machine used. Detail parameters see week6.

Do a quick routing and manually adjust the lines.

Push to 3D design and export the result.

CAM Design with MODELA ​

Import the board design into MODELA.

Define the cutting position.

Set the machining process type to Finishing.

The tool parameters are entered and selected.

Set the cutting area and depth.

Choose the type of tool path.

Set the basic cutting parameters.

See the overall output machining plan.

Manufacturing in progress ​

The machining of the board start

It seems the machine bed is not level enough. The half of the board has been machined successfully, but the other half has not been cut properly. So we have to increase the cutting depth and process several more rounds.

There are some burrs on the edges of the cut board.

Sand the board with sandpaper to remove burrs and adhesive at the back.

A final look of the machined board.

Soldering ​

The tools usd for soldering process is shown in below.

Soldering is challenging for me.

When soldering the first row of pinheads, one solder joints didn't turn out well and I decided to redo it. Unfortunately, I accidentally break the circuit line nearby so I have to use jump wire to reconnect the circuit.

The finished board is not good looking but still it is my first board.

Few Tips

  • Make sure the soldering iron tip is clean. If it oxidizes and turns black, clean it promptly with a steel wire ball.
  • Use flux, but avoid using too much.
  • Don't leave the soldering iron tip on the component for too long. Prolonged high temperatures can lead to soldering failures.

Testing and Demonstration ​

Here is the code that I use to test my board, this code controls three LEDs connected to digital pins D10, D9, and D8 of the XIAO ESP32. In the 'setup' function, these pins are initialized as outputs. The 'loop' function then sequentially turns on each LED for one second, turns it off for one second, and moves to the next LED. This creates a repeating pattern where each LED lights up in turn, stays on for one second, and then turns off, providing a sequential blinking effect.

// define led according to pin diagram
int led1 = D10;
int led2 = D9;
int led3 = D8;

void setup() {
  // initialize digital pin led as an output
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
}

void loop() {
  digitalWrite(led1, HIGH);   // turn the LED on 
  delay(1000);               // wait for a second
  digitalWrite(led1, LOW);    // turn the LED off
  delay(1000);               // wait for a second
  digitalWrite(led2, HIGH);   // turn the LED on 
  delay(1000);               // wait for a second
  digitalWrite(led2, LOW);    // turn the LED off
  delay(1000);               // wait for a second
  digitalWrite(led3, HIGH);   // turn the LED on 
  delay(1000);               // wait for a second
  digitalWrite(led3, LOW);    // turn the LED off
  delay(1000);               // wait for a second
}

Light up my first PCB :