Just a few ideas:
Maybe this SkyDelta design could actually be used for 6 degree of freedom? Or rather 5 degrees of freedom. Anyway similar to the sextupteron. So instead of designing ways to keep the wires tout etc you add 3 more stepper motors but can tilt the head instead. Wouldn't be cheaper, but you might turn an engineering challenge into an advantage.
PS: Seems Tray already suggested the "Spike" design already on google groups, but 6 motors seem to be pretty problematic atm.
As a way of calibration, maybe add a few IR LEDs on the extruder and do simple motion tracking with a camera on a Raspberry PI or Beaglebone.
Maybe this SkyDelta design could actually be used for 6 degree of freedom? Or rather 5 degrees of freedom. Anyway similar to the sextupteron. So instead of designing ways to keep the wires tout etc you add 3 more stepper motors but can tilt the head instead. Wouldn't be cheaper, but you might turn an engineering challenge into an advantage.
PS: Seems Tray already suggested the "Spike" design already on google groups, but 6 motors seem to be pretty problematic atm.
As a way of calibration, maybe add a few IR LEDs on the extruder and do simple motion tracking with a camera on a Raspberry PI or Beaglebone.