Eventually the chair caster wheels had to be replaced with a lazy susan bearing.  The lift was working pretty good but I had to play with the output settings a little bit to prevent it from moving too quickly downward.

Overall, I think this would eventually work but the camera would lose track of the person if it moved too high.  I need to add a tilt mechanism to capture the top of my head, the automatic hole filler in Skanect would leave a dimple instead of a dome.  Everything was just too finicky to keep going.

I was able to get decent enough results but not good enough to warrant purchasing the software.  I might revisit this project but if I do it will probably be to create a camera dolly that rotates around the person.