Hopefully you can see these two files. I was looking around my old magazines the other day for something. This has one deficiency, which I have an image that corrects it. On concrete which is not a level surface it won't level So you can use the small drawing to fix the side with 2 feet, below the midsection to adjust for an out of level floor. This is a nice stand,better than the fold ups... you can do the three heads, plus you can also do a large flat sheet of ply 24x24 for a nice work table... use the flanges that you can get for the pipe and they will all work well.
Other's might find it interesting.
Let me know if this doesn't work, my first use of google drive.