Here's a quick update :
Finally got the placement to a point to where i'm satisfied it will work well for routing the way i like and adequate isolation and grouping of sensitive bits away from noisy bits etc, and got the motor drivers routed on top, which you can see on the top row - XYZ on the left, extruder channels on the right.
In the end i was able to squeeze in both DAC''s and traditional trim pots, so i can use either.
Sorry there's no 3D models of the connectors and other large parts yet, those take time to track down and load in so i'll only get to that once i'm all done with routing.
As it stands the board itself is 170mm X 60mm but as you can see some of the connectors cantilever off the board a bit when they're installed, which might add another cm or so to the dimensions when you count that. i may increase the board just to better support those connectors but without pushing them further out, so effective size wont really get any larger.
There's quite an array of optional power connectors over on the left edge, some of them i don't expect to be popular overlap each other so you can put one or the other but not all of them - however you can get 2 and maybe 3 options in parallel, including the 1/4" faston tabs, ATX connector, and pluggable screw terminals.
Thermistors are on bottom edge on the right, and thermocouples on the right edge - they along with all the motor connectors all use the same 8x 3.5mm SMT screw terminal block - though i might possible redesign the pad to also support a through-hole version should the SMT pins prove to not be great in taking the usual abuse - though i have already used the SMT ones in a commercial design and they seem surprisingly strong.
There's a RS-485 transceiver that occupies the last 2 spots on the right end of the thermistor interface.
For the Thermocouple interface i actually manage to fit 3 different versions of the circuit so i can build it as a 1 channel, 2 channel, or 4 channel model - assuming there's any demand for that at all.
The heater outputs are along the bottom edge on the left, with the FFC header for my heated build plate as well.
As you can see I had placed the USB connector just above the CPU in between motor drivers, mainly because i wasn't sure if there would be room anywhere else, and that's the side of the CPU with the USB connection. Well it turns out i could fit everything with some room to spare so i will probably move that to bottom edge instead and put a motor voltage bus electrolytic cap up there instead.
Also i don't have the LCD connector on yet for same reason but that will go on the bottom edge below the CPU - also its hard to see the little SD card connector there just below the CPU a little to the right side, but i might be able to switch that back to a more traditional SD card connector along the bottom edge too.
There's still quite a lot of little tweaks, cleanup and DRC checks to run, but the hard part is finished, the rest of the routing will be a breeze -
Unfortunately i have never been so busy with work projects so the time i can put on it this week is going to be next to none, but i should have this finalized and ready to send to fab by the end of the coming weekend nevertheless.
Then i'll get all the 3D bodies on the board for some prettier renderings and output an .STL file for anyone who wants to play with fitting it on the ORDbots
EDIT: if you look carefully ya might spot a few other goodies i forgot to mention, like the dip switches for configuring stepper mode and a few other things, like locking the write protect on the DAC's eeprom, setting RS-485 bus address, etc.
there's 4 RC servo headers just above that.
Also it seems that of all the signals in the ATX connector, there's only one 12V pin/wire, but lots of 3.3V and 5V - so not so great by itself for all those pins. What we really want to use is the optional 4-pin xtension, which is often seperate, which is usually for CPU core voltage regulators - this one has 2x12V and 2x GND lines. so i'll probably eliminate the DIN connector and pit that in there instead, but scooch down the ATX connector and install it at the top left corner instead.