Dust System Duct Arm Support

Not wanting flex or pipe (for dust) on the floor, but nothing to drop the pipe from above (timber frame), I'm considering building this overhead "arm" to support and move the duct. Not sure if I'll weld (steel) or just laminate out of wood, probably the latter. The flexible coupling is one of those "ball-joints" offered by Spiral and Nordfab among others. Key is to get the pivot of the arm directly over the center of that ball. Could also use a short section of flex in place of the ball-joint. Anyone have experience building or using and advice on what to ... or not to do?



Attachment 282393


Attachment 282394

I'd extend the pin (solid black in the elevation view) above the swinging extension and stretch a tension wire to the distal end of the support to form a triangle.