My enormously complicated, enormously fun DC throttle project

[mmagliaro]

John,
I designed all the boards myself using KiCAD (main throttle, receiver, transmitter, pulse generator, and a few other little ones that are only used
for the "power pack version").  KiCAD is awesome, free, and VERY intuitive.  It also includes a massive library of 3D cad models of the actual components, so you can have it render you a 3D vision of what the actual populated board will look like (and any models it doesn't have, you can usually download from sites like Digi-Key or Mouser on the page from the component, or from various other component CAD sites like GrabCAD).
It uses the netlist from the schematic and enforces it when you design the PCB, so you won't screw up and leave something unconnected, or short traces to each other that shouldn't be, and so on.  In my case, I already had the schematic from another tool, so I did not redraw it in KiCAD.
Instead, I used somebody's "WireIt" plug-in to KiCAD which let me specify the nets ("what-connects-to-what") by hand (but graphically, by clicking components on the PCB).

It spits out the Gerber files that PCB makers all need, and many of them will just take a zip of your KiCAD project directly.

As for where I got the boards made, I started by using aisler,net.  They are based in Germany, but have a manufacturing plant in Houston, so the labor is US-based for US customers, and so is the shipping (and no import duty).  They cost about $8/board.  Turn-around time was very slow, about 3 weeks, but I was willing to put up with that to keep the labor US-based.  But I became frustrated by their poor customer service.  Inquiries can only be made through public message forum.  It took days for one of them to reply.  And my question about making boards with a black silk screen was reponded to with a confusing, and completely wrong, set of answers from more than one person at Aisler.  It took weeks for me to get a straight answer out of them (and the answer was ultimately, "No, we can't do any color but green").

Soooo..  much as I did not want to, I was forced to go to a China supplier, JLCPCB.  I tried about 20 US companies, and they either wouldn't touch a small job, or couldn't do black, or wanted about $25-$30 per board, which is so oppressively expensive that it's out of the question.  JLCPCB does them for about $2/board.  But on a 5-board order plus the shipping from China, you end up spending about $35, so $7/board is the end cost.  Of course, on a larger order, the shipping would be much less of a factor and the cost would come down.  The other thing about JLCPCB is that they are stunningly responsive.  My questions were almost always answered instantly through a chat window, no matter what time of day or night.  One time, they even had to look at my board layout to answer the question, so they grabbed while we were in the chat window, and opened the gerber files to check something before answering my question.  It takes about 8 days from the submitting the files to when I have the boards in my hand, which is amazing.

[mmagliaro]

Here's a 3D render of the maint throttle board from KiCAD:
The posted image doesn't do it justice.  You can rotate and zoom this view in the tool, and all the letting and edges are rendered crisply
and accurately.  You don't appreciate how important this rendering is until you use it.  Then you immediately see problems that you won't see
just by looking at your PCB layout, like components that are positioned so as to make it clumsy to insert them, or terminal blocks there it's
too hard to get the wire into them because of some nearby component, or things that get hot being badly placed near components
that really don't like heat.
The rendered 3D components are all good likenesses of the real parts.  Those relays are not, because I didn't bother to hunt down the
correct CAD file for those.  They are just generic relay models with the correct footprint and pin-out.

[mmagliaro]

Just to let folks know, I have not "dropped" this.  I am in the process of building one and timing myself to see just how long it actually takes to build, so I can add that to the cost of parts and come up with how much it would cost to make one for somebody else if they want one.  I also have a complete technical guide written that explains how all the sections of the circuitry work, has a complete parts list with schematics, and an illustrated assembly guide.  My goal here was to build it and have it documented, whether I ever build any for other people or not.  I don't want all this work to disappear when I disappear someday, like what happened to the GML throttle.