With the help of a friend (and perhaps more importantly his welding equipment!), I made one last year. I'll try to post a picture here. I can take close-ups and such if you want - PM me with an email address and I'll sort it out.
It's pretty easy though: a piece of steel for the base, about 1/16 thick or so, bent up at an angle to stop it catching. To that, weld a darn pipe in the middle; diameter such that Oly plates can fit on it, long enough to take as much weight as you think you can handle (I can DL a helluva lot more than I can drag). I also welded two small angle iron to the base - simply to allow me to lift the first weight on and off and still get my pinkies underneath. Finally, drill a hole in each corner, and use strong steel clips to attach chain / rope and you're all set.
To say the least, this is a very unsophisticated piece of fitness equipment.
(Note: I'm away on travel tomorrow onwards, including attending the D.C. conference, so it might take me a few days to respond to a request for detailed pictures, but I am more than happy to do it).
Posting the picture might take me an attempt or two to get the size right...