I needed an articulated arm to hold my axis webcam so I made this. It can also hold anything else as I made the adapter pieces as well. It is flexible and can be locked in place by tightening the base knurled ring, which pulls and tightens a string (ideally a strong non-stretchable thread like dyneema fishing line).

You can print as many of the segments as needed. For better position holding, sand the curved cups and ball, and coat with some kinds of rubbery paint or coating. Alternatively, you can make rubber washers from bike inner tubes, that works well too.

The small knurled nut as well as the stem and stem holder that allows to mount a camera or any other accessory you want is available as part of my led 2020 extrusion mount here https://www.thingiverse.com/thing:6938591

How to assemble:

• Print all the parts, and as many of the articulated_arm_segment as you want.
• take a loop of non stretchy string (dyneema best), pass it through all the segment so that the last segment (which should be segment_axis_base) has a loop formed by string going out the cylindrical part and back in the hole through all the segments.
• Place the axis_base_thread_plug in that loop, pull the string from the base side so the string is locked by the plug going into the segment_axis_base.
• on the base side, make a knot with the thread going over the base_thread_plug, knotting across as tight as you can againt the chain of segments.
• insert the base_thread_plug into the base cross-shaped opening
• pull the articulated_arm_nut_with_knurling over all the segments and screw it on the base. It will pull the base_thread_plug into the base and pull the string, tightening the segments and rigidifying the whole assembly.
  If needed, if the string was a bit too long or more clearance is needed, use the articulated_arm_base_spacer between your mounting surface and the articulated_arm_base

see more stuff on my blog.tinkerbox.org