I have thought up three or four methods for making circuit boards with 3D printers, each with it's particular advantages and disadvantages. The one I will describe here is my chosen method, one that might be called the Guided Wire method. See the images below for reference.

WireEmbedding2.jpgwires3tries.jpgCubism.jpg

in the first image we see the method of guiding the wires, one of creating a round trough with a smaller channel above it. The channel is just wide enough to accept the wire, and the wire once forced into the trough with your fingernail or other appropriate tool resides in the cylindrical region below the surface. The second image shows the attempts that I made in doing this. I found that a multiplier of 2.75 times the radius of the wire works best for ABS on my ROBO3D printer's glass bed. Note that the diameter of 22 gauge wire is 0.644mm. In the third photo we see the "breadcrumbs" that I posted to Thingiverse a while back, basically 3D printed perfboard.

Now that I have wires (with some labor involved) and parts holders (perf board or part footprint), I'll need to make an example for soldering. Then after that some trace crossings perhaps and that will be all we need for a 3D printed circuit board!

Les