I've just assembled the new head mechanism and I'm quite pleased with it!

The assembly will allow the head to pitch and roll in order to stay level in response to external disturbances (terrain mostly). I want a level head for mounting sensors and I think it'll look cool. There's a small slip-ring embedded in the center allowing 360° rotation via the gearhead motor clamped to the side. The whole thing sits on top of a linear actuator giving 150mm of vertical travel to provide clearance for pitch and roll but still allowing for a compact "stowed" mode.

I was happy to finally get this assembled as progress had been slow recently with a few hurdles to get over. My cheap 3D printer has not been liking the cold either and spare time and money are of course major constraints, I guess they are for most people.