At electronics-club at work, one of our long-running, slow-moving projects involves building a wireless, multi-node, Arduino-based sensor system. This system will consistent of multiple, independent nodes, all reporting their local temperature and light level readings to a master node wirelessly (more on this in a future post!).

We are currently at the stage where we have a working prototype on a breadboard:

A few weeks ago, I created a PCB design in KiCad. I have opted to etch my own PCBs first, to validate the design, before ordering a batch from dirtypcbs.com.

After several failed attempts, I ended up with this little gem:

(Ignore the the bottom right corner; caustic soda is a pain and I got impatient!).

As the PCB design uses through-hole components, I needed some kind of drilling solution. A quick search later I discovered that a PCB mini drill press is not exactly cheap. Certainly more expensive than the amount I'd be willing to spend on a hobby project.

A good PCB drill press has a few important features:

• High RPM. At least 10000rpm, but faster would be better.
• The vertical movement should be granular enough to allow the drill bit to move through the PCB slowly.
• The horizontal slack in the drill press should be absolutely minimal, as the very thin (0.8mm) drill bits tend to break easily.

This lovely and cheap rotary tool kit filled the first requirement nicely. This set offers a lot of kit for just £15.

Inspired by this instructable, a macro shot focusing rail works for the second requirement.

By using some scrap wood, two old springs from a broken balanced-arm lamp and these 3d-printed clamps (thanks to @insom for printing these for me!), I've come to this end result:

And in case you're wondering: that elastic band is there to fulfill the third requirement. The macro-rail has a little too much slack in it, which is completely countered by the elastic band.

So far, the total cost of this project is:

• Rotary tool: £15
• Macro slide: £10
• Some 0.8mm drill bits: £3

I'm currently awaiting the delivery of the drill bits, after which I can finally drill our prototype board!