There is even a chance you would have most of the frame laying around somewhere for one of the two major styles in home built.

Threading rod acts are a super effective down ratio gear. Not good for 3d printing because does not move fast. But for pcb milling were you want fine movements absolutely perfect.

mantis and other methods using matched drilling are the fastest to get exactly right.

The motors to a point can be recovered from items.

Yes its one of those surprising things most people don’t know how cheap a very decent pcb mill really is. Or the fact most of the time they have the parts require for frame laying around as scrap.

Now that I am retired, the little woman will probably not allow me to purchase new toys. I have to use my old technology salvaged from the workshop. I can make FeCl₃ if I cannot buy any and a Sharpie^TM marker might have to do if my etch resist is dead… I have a “dentist’s drill” (the little woman bought it as her toy I kid you not…) The renovations of the old homestead brought a mixed blessing of fatigue and trial-and-error combined with a few new technologies like an air-compressor and nailer.

Simpler than solid board multi layer.

This is where it gets funny. What you are using is standard off the shelf ink-jet printers particular models and you have replaced the black ink with silver conductive(of course you want a brand new clean head so forget everyone where the head is integrated into printer tank). The base plastic your normal overhead projector plastic will do.

http://www.methode.com/sensors-and-switches/conductive-and-resistive-inks.html

Yes you can print resisters straight into the circuit by having multi ink tanks with different inks with different conductivities.

Less toxic chemicals. Does have a downside you have to glue parts on not solder(hang on how is this a downside with kids the glue is strong so kids really connected to the circuit board is a issue if you use it with kids) and you cannot use IC chips that get very hot. Also you have to worry about mounting the sheets stable.

Robert Pogson I know this method because I was renting somewhere and was not allowed to etch but I still wanted to mess around with boards.

Silver you can do in the same room as you no toxic fumes to worry about.

2 layer can be insanely fast on a duplex printer with silver inks.

Really this takes less skill and time etching. I am also lazy I also have a PCB mill. Again no major toxic chemicals.

I have not used FeCl3 in over 10 years. Between silver inks and PCB mill why would I. PCB mill the board comes out all drilled. Having to etch then drill is just extra pain in but.

For a lot of fit-in-the-hand gadgets, two-sides works pretty well. Imagine my gadgets with a few discrete parts and a small number of up to 16-pin ICs. I have a box of thin clients if I need more complex devices. You could probably manually combine two-layer sections to make up a multi-layer board with Fritzing but making multi-layer boards is beyond the capability of many. Two-layer can be done in the garage workshop of anyone using spray-on etch-resist, FeCl₃, two transparencies, a bright light or Sun and a tiny drill.

Phenom there are a lot of different EDA.

The thing is Fritzing is not a generic do everything EDA. Its been design with the Arduino in mind. Fritzing does not do multi layer boards. Two sided yes multi layer no.

You can copy you circuit layout from a breadboard into the program and it will produce the circuit diagram and shield design. AutoTrax Design not that useful for that. Neither are the rest of the EDA really. Most of the EDA are design to go from circuit designs to boards or from boards back to circuit designs. Not from breadboard to circuit design to shield for anduino.

Fritzing still lacks good simulators.

Fritzing is interesting from the point of view that a prototyping solution is now getting custom software to expand it. Maybe raspberry pi might get the same thing.