I might be wrong but I think that modifying the PhlatPrinter 3 might be both better and easier than trying to design a whole new machine

for exsample:
- Raise the height of the Gantry on the PhlatPrinter to about 4'.
This will give it the tallest build area on any 3D printer available as well as give the PhlatPrinter it's own stand.
- Move the Z axis to the build platform.
This works for all applications, milling, plotting, and 3D fabrication allike.
- Build interchangable build platforms with a quick connect to the stepper motor.
One for flat milling and plotting (the current design for the PhlatPrinter 3 with the pressure and drive rollers), and a square sliding platform for the 3D printing as well as 3D milling.
- Build an interchangable extruder head attachment.

I believe this is the better option all around because you will only need one machine instead of two which means less clutter and more versatility, plus all your hard work making the current attachments for the PhlatPrinter 3 won't be wasted.

Thank you for your time, please let me know what you think and I hope if you have any contributions you will post them as well

Let's help Mark build the best machine possible and help him with his mission to bring fabrication back to the people.