Designing a simple breakout PCB for a 3D printing project

 I was approached by a bloke on facebook for a price to design a simple breakout PCB for a 3D printing project he is working on.  As the board was relatively simple and it was for an open source project I decided to do it for him for free.  In return I get to blog about it!

The board itself was part of a 3D printer dual extruder purge controller.  The purge controller uses servo motors to control when a filament change occurs removing the requirement for a purge tower and less filament wastage.  The unused filament is extruded as blobs into a small hopper on the side of the 3D printer.

I must be clear that I did not design any of the circuitry or write any firmware so I cannot assist with the specifics to the project - all I did was layout a PCB.

The circuitry and components used were supplied as a fritzing diagram:

Blobster Fritzing Diagram

The board had to be a specific size to fit an already designed enclosure.  The board size had to be less than 47 mm by 40 mm.  After discussion with the lad on facebook the only parts needed on the board were:

1x Arduino nano every 

1x 15k Resistor

1x 10k Resistor

4x 3 way 2.54' pitch header pins

1x 4 way 2.54' pitch header pins

1x 6 way 2.54' pitch header pins

1x DC barrel jack socket

Everything else will be connected off board via the header pins.

Once all was agreed I fired up kicad and drew up the schematic diagram:

Blobster Schematic Diagram

I then selected all of the PCB footprints.  I actually find it quite useful that Kicad forces you to choose footprints before you start layout.  It prevents you from selecting parts you cannot obtain or solder!

Next I swapped to the PCB design and usually for me I chose to set the board dimensions first and then began arranging the components to suit.  Normally I rotate and move the components around in the rats nest until I get the best electrical connections and groupings and then set the PCB size.

After that was complete I did the routing of the tracks.  There was nothing special about the circuit - no high current traces or impedance matching was needed.  I didn't even bother with a ground plane - I was in a rush!

Here is the final layout:

Blobster PB layout with dimensions

  I also checked the 3D renders out just to make sure all was well.  I really find this feature useful

Top down render

Isometric view of the PCB in 3D

I then plotted the gerber and drill files and sent them to the customer (bloke from Facebook) - He uploaded them to PCBWay and got a quote for £18 including delivery!  I believe all has gone well and he is expecting delivery soon.  I will post images of the boards etc when I get them.

That's all for now - Langster!