I stopped hanging out in /r/DIY before /r/DIWHY became a thing, because it was turning into a roast of people risking life, limb, and property by doing something structurally unsound. There's educating people on building standards, and then there's just bagging on people. In an attempt to be more of the former than the latter, if the string or especially that strut sheer off of their mounts, that whole contraption is…
I searched for products to compare to and found these: http://www.ergoquest.com/overbed-workstations.html These contraptions cost more than my car... But they do seem to be safer. Nothing hanging above the user's head.
I was trying to find a used/rent/borrow arrangement for a device called a log arch a few years ago, to help with a landscaping project. This is how I discovered just how many people have learned to basic to intermediate welding to avoid the labor costs of having someone else do low-volume work for them. Especially out in the boonies.