How to make a PCB ruler

You'll need to download the Gerber file and open it using a PCB CAD tool of your choice. If you've never designed a PCB before, I recommend Ki CAD or EASY EDA.

The Micro controller pin outs are all on the top layer and everything else is on the bottom layer. You can change them around, but sometimes the shapes will be turned around if you change sides. You'll need to decide which board outline you'd like to use, and delete the other two. From there, you can choose the components and footprints to add to your ruler, then drag them into place. Note that nothing is grouped. To drag a component, you'll need to select the whole thing first. Once you've got your ruler looking the way you like, just delete everything else and you're ready to order your ruler from a PCB fab house of your choice. If you do decide to try this, please post a picture of your work in a comment here. I'd really like to see it!
 

Here's a few tips:

• When ordering your ruler, always choose ENIG (Gold plated) or sliver solder. Lead is toxic and it just doesn't belong on a ruler.

• Use the render function in your CAD tool to preview your ruler. Print it out on a piece of paper when you think you've got it perfect. This will help, but if you ask me it takes 2 or 3 tries to get your ruler looking just perfect.

• The main layers you'll need to use are the top and bottom silkscreen, top / bottom (copper) layers, and the solder mask layer. To get bare metal, you need to have a top or bottom (copper layer) and an identical solder mask layer. Everywhere that is not part of the solder mask layer will be covered in solder mask. Silk Screen is the layer for text and graphics. It is essentially white paint that goes on over the solder mask.

Here's an assortment of a few other open source PCB rulers if you need some more ideas:

• Timmy29965's PCB ruler:

This one's in German, and it's pretty darn cool! I learned from my first PCB ruler campaign that some countries use U to express volts in Ohm's law! You'll see that on this ruler.

https://easyeda.com/Timmy29965/pcb-lineal

• MJ's PCB ruler:

This one's got a lot of nice SMT component footprints in a neat square shape. I really like it!

https://easyeda.com/TCorny2017/a-state-ruler-pcb

• Yeo Kheng Meng's PCB ruler

A really nice rectangular ruler with a nice assortment of SMT component footprints, and a beautiful back side.

https://github.com/yeokm1/open-source-pcb-ruler

• And last but not least, the Adafruit PCB ruler.

This one is my least favorite of the bunch, but it's really common so I thought it was worth mentioning.

https://github.com/adafruit/Adafruit-PCB-Ruler

• If you're having trouble downloading or importing my ruler, you can also find it here on OSHW Lab.

https://oshwlab.com/idunn/raspberry-pi-arduino-and-electronics-pcb-ruler-v3-0

Image caption:

This is my collection of PCB rulers. Included is the Digirule 2 U, The Alpenglow Industries PCB rulers, the Nvidia PCB rulers, and of course my own Bolt Industries PCB rulers.