Punky's New Brew - Part 2

Converting a Breadboard Experiment into a Professionally Manufactured Eurorack Module

In this blog post, we’ll discuss the key steps required to turn a breadboard experiment into a professionally manufactured device for Eurorack. We’ll primarily focus on using KiCad and Inkscape with the Synth Panel Designer plugin.

1. Introduction

In our previous video, we explored the creative process of combining known circuits to create a percussive arcade sound instrument. This journey taught us about the 555 timer, simple Attack/Release circuits, and basic VCAs made from vactrols. Today, we’ll walk you through the process of transforming our breadboard experiment into files ready for manufacturing. Please note that to keep this blog post concise, we’ll cover high-level concepts and essential details for manufacturing.

2. Preparing for PCB Design

Before diving into PCB design, consider the following:

  • Power Management: Eurorack power supplies typically provide +12V, -12V, and Ground, with some also offering +5V. Ensure polarity protection, bypass capacitors, and a ferrite bead for clean power.

  • Component Layout: Plan the layout of your components. For drum modules, think about splitting the circuit into multiple PCBs and using connectors for interconnections.

  • User Interaction: Consider the arrangement of components on the control board, placement of jacks, knobs, buttons, and visual elements. Plan for graphics or artistic use of PCB layers.

3. High-Level PCB Design Process

Here’s a high-level overview of the PCB design process:

  1. Schematic Capture: Use the schematic editor (eeschema) to recreate your circuit.

  2. Component Footprints: Choose accurate footprints for each component and ensure they have reference names.

  3. Rules Checks: Frequent rules checks are essential to catch critical issues.

  4. Layout Design: Create your module’s front panel layout, considering component placement.

  5. Using KiCad: KiCad is a powerful and open-source tool for PCB design. It offers extensive features and community support.

4. Schematic Capture

Capturing your schematic is a critical step:

  • Consider breaking up the design into logical blocks if the circuit is complex.
  • Test your circuit on a breadboard before capturing the schematic.
  • Ensure all components have reference names.
  • Perform frequent electrical rules checks to catch issues early.

5. Component Footprints

When it comes to component footprints:

  • Add footprints as you add components to save time.
  • Ensure footprints are accurate by referencing datasheets and measuring physical parts.
  • Have actual components on hand for reference.
  • Consider making use of private component and footprint libraries to save time on frequently used components.

6. Layout Design

Plan your layout with considerations like component placement and adhering to manufacturer rules.

  • Start with the most constrained components first, such as pots and jacks.
  • Give components enough space for easy assembly.
  • Adhere to the manufacturer’s guidelines for clearances and track sizes.

7. Routing

Manually route your PCB for better results.

  • Use different track sizes for power and signals.
  • Avoid running tracks between pads whenever possible.
  • Stay organized and tidy for troubleshooting.

8. Gerber File Generation

Generate Gerber files according to your manufacturer’s requirements:

  • Review the manufacturer’s specific rules for file generation.
  • Create separate sets of files for each board if you have multiple PCBs.
  • Include a drill hole file.
  • Consult your manufacturer for board size information.

9. Ordering PCBs

When ordering your PCBs:

  • Choose the type of board (FR4 is a common choice).
  • Decide on the number of layers based on your circuit complexity.
  • Select solder mask and silkscreen colors.
  • Consider placement for the manufacturer’s number.

Also be sure to check this the project sponsor:

10. Conclusion

Today, we explored the essential steps to transform a breadboard experiment into a professionally manufactured device. We discussed considerations for PCB design, the process of schematic capture, and the transition into PCB layout. We also covered preparing and exporting Gerber files for manufacturing and how to submit them for production.

Remember, this blog post only scratches the surface of PCB manufacturing. If you’d like more in-depth tutorials or have specific topics you’d like us to explore in our lab, feel free to share your thoughts in the video comments.

11. Closing Remarks

Thank you for joining us on this journey. We started creating these resources because we believe that sharing knowledge is a valuable way to learn and grow. We’re here to support you on your own learning path. If you have experiences, tips, or questions to share, don’t hesitate to leave them in the video comments.

If you enjoyed what we are up to and would like to see more consider subscribing to our YouTube channel. Your subscription helps us and keeps you informed about new content. Until next time, stay creative and support each other!

Additional Resources

All supporting files are available on our GitHub page here