I'm thinking 25mm SHS arc welded frame,
Worm drives from a car wiper motor,
500w grass trimmer spindle,
er11 to 25 say workholding,
nema 17 or 23 steppers,
24v psu, toshiba drives.

It would have to be 4 axis to do a helix, or 5 axis for a ball nose cutter with relief.
No bigger than a shoebox, maybe welding isn't even required.
I'm sure there would be lots of interest given most people here would already have all this stuff from early experimentation.

Thoughts? Interest?