"BTW, the square tubing with rounded corners is not the ideal section to be working with, and the added welded sections to make the corners square is bad design."
How would you suggest building the column and base? I would like to keep the machining as simple as possible, that's why I went with a steel tube. I like the idea of welding steel rods diagonally across the tube. What is the disadvantage of squaring the column by welding steel bars to it?
I think I may be forced to go with a counter weight or air spring to support the head due to cost and complexity reasons. I suppose I could use a spline type shaft to drive the head. I will have to investigate the complexity of this.