I am working on a project for which I have to rewire a Williams EM Stardust pinball machine. To make sure I will be able to rewire it correctly, I wanted to redraw the original schematics diagram. To do that, I ended up creating and releasing my own symbols library for QElectroTech with symbols for drawing Williams EM schematics diagrams.

Before I started cutting wires from the working pinball machine, I wanted to have a clear and complete schematics diagram. The diagram had to exactly match the machine’s actual wiring if I ever want to make it work again.

The only schematics diagram I had for this machine was a scanned version from IPDB. Because it is a scan of an older document, it had a number of unclear areas which were hard to read. Also, its size made it hard to work with, as these schematic diagrams were hand drawn as one continuous diagram on a single sheet of paper.

I started looking for a program to draw such diagrams with. I prefer to use open source software for these kind of hobby projects. Another requirement was that the program would allow for creating custom symbols. I soon found QElectroTech, which looked promising.

The first thing I did was creating custom symbols. QElectroTech has its own symbol editor which makes creating custom symbols a straightforward process.

Williams EM symbols

With the symbols above, I was able to redraw the original schematics diagram. I later shared this symbols library on Github and posted it on Reddit.

From there, it got picked up by one of the maintainers of QElectroTech. He asked me to create a pull request to merge my symbols library into the QElectroTech repository. And that’s how this library became part of the QElectroTech project.

And what about the actual project? You’ll read more on that project in another blog post.