OK, now onto mechanical stuffz (yay!, I get to use the Shapeoko).
Overall I'm pretty happy with the build. While this seems to be a lot of work to create a box and switcher controls that could otherwise be facilitated by plugging/unplugging wires or with flashing/reflashing, but that's not how I roll. Additionally, I got to expand my fabrication and tool-chain experience by making a PCB with my machine.
I need to engrave some nameplates, create a base/stand for the box, and also create some selector-switch operators (these will insert/protrude thru the 3 holes on the bottom edge of the cover). I originally had the notion to create a single ganged-switch operator such that I could actuate all 3 switches at once. After playing with a few mock-ups, I ditched that idea in lieu of individual push/push controls. No matter how I tried, invariably I'd have an outside switch that would not transition with the other two.
I vacillated quite a bit over how I wanted to control my AC motor devices (router/vac/etc...). I know I didn't want any AC near my DC controls, so I ended up hacking a couple 433 MHz remote control AC modules and mounted On/Off switches on the box to control these. I have a dedicated 12V linear regulator on my switcher board to power these (no more N cell 12V batteries!)
My E-Stop circuit is wired in the classic sense using the NC side of the push button to series-interrupt +24V to the CM controller boards. The NO side of the push button parallels the Router Off pushbutton. So, slamming the E-Stop switch kills +24V to everything and also provides a continuous Off signal to the Router control module.
I also added a 3 conductor 1/4" phono-plug to the top of the box for a quick and easy touch-plate connection. While the Carbide 3D touch plate is coming (and requires a dedicated +5V and ground) I've got 3 of the 4 connections available should I be convinced to purchase one (I'm still waiting for an explanation of the benefit of a "more sensitive" touch plate). These connections are parallel between both controller boards (pin polarity observed).
I'm running the GRBL controller with the Shapeoko homing switches, however I'm not running the ESTL controller with any homing or limit switches.
Enough babble.. here's another 2000 words worth: