Milling a Circuit

Project by Jeremy Fryer-Biggs

making a custom speaker with your microfactory!

This project combines our love of music with our love of design and showcases the Microfactory's ability to mill woods and etch circuit boards. We created a custom circuit based on MAKE's "Cracker Box Amp" and a beautiful walnut and birdseye maple housing. This speaker is not only functional enough for your next outdoor BBQ with friends but sexy enough to fit in to the most refined decor.

project parts list

  • printed circuit board
  • wood of your choice for sides (we love walnut)
  • wood of your choice for front (for contrast we used birdseye maple)
  • wood glue
  • screws (keep one side unglued so that you can access the battery)
  • high grit sandpaper for polishing (I get mine at autozone)
  • flux
  • solder
  • soldering iron
  • (2x) capacitor 15uF
  • (1x) 10 ohm resistor
  • (1x) electrolytic capacitor 100uF
required bits

You will need an engraving bit for making the circuit board and a 1/8th downcutting bit for milling out the sides of the speaker casing

Eagle Speaker Circuit Layout Image By Jeremy Fryer-Biggs

speaker amplifier circuit

We started by drawing inspiration from this MAKE design. After doing a little parts research we laid out the basic circuit design in Eagle

Eagle Speaker Circuit Layout Image By Jeremy Fryer-Biggs

Next we exported the file as a .dxf and imported it into CAMBAM to create our toolpaths

CamBam Circuit Tool Path Image By Jeremy Fryer-Biggs

Then we routed the design out of PC board

Etching the Circuit Board Photo By Jeremy Fryer-Biggs

(A short video of the machine routing the board)

Once we removed the finished board, we soldered on all of the components

Soldering the Amp Circuit Photo By Rachel Tine

speaker housing

Next we designed the outside. First we created a CAD model using what we knew about the board that we designed and the components we selected

CAD rendering of Speaker Image By Jeremy Fryer-Biggs

Then we exported the individual part files to CamBam

Toolpaths For Speaker Side Generated By CamBam Image By Jeremy Fryer-Biggs

We milled out the top, bottom and sides in 1/2in walnut

And the front and back in 3/16th birdseye

Finally we assembled all of the pieces

Assembling The Speaker Photo By Rachel Tine
Assembling The Speaker Photo By Rachel Tine

Glued it together

Final Gluing Photo By Rachel Tine

And voila a beautiful working speaker that can connect to your mobile device!

Finished Speaker Photo By Rachel Tine

special thanks to

Gene Casey - for helping with the design work

Rachel Tine - for doing the cool photography

Ed Vogel (MAKE) - for the electronics inspiration

Ben Adler (Jamco)- for the high pass/low pass filter idea