I really want access to some stall bars, and the couple DIY versions that have been posted have inspired me to make some for my gym, but I'm looking for some feedback on my plans before I start trying to build and install them. Here's the basic plan I've drafted up (large-ish jpg) http://i.imgur.com/0mz7K.jpg
I bought a 36" long 1 3/8" diameter Douglas-fir dowel and stress tested it by supporting about 270lbs on it, and it seemed sturdy enough (I'm not that big, nor shall I ever get that big short of getting really fat or maybe, possibly going all out in strongman training, but even even then it is unlikely, but there are some members who are in the 250+lb range at my gym, and I want the unit to be sturdy enough to support anybody who would like to enjoy the benefits stall bars provide).
It doesn't have to be 88" tall, that just seemed like an okay measurement to start with after looking at some retail models. I'm wondering where would be the ideal locations to place the back braces, and if the configuration of attaching 9" long pieces of 2"x6" boards perpendicularly at the top for the highest rung will be sturdy enough without further fortification.
Update: I got the unit built and installed. I took some of the advice I received (thanks, by the way!) and went with a simple rung configuration and omitted two rungs between the top and the next one down. There are some things I'd change and do differently if I ever build another one, but overall, I'm pretty happy with it. Here's a picture: http://i.imgur.com/b6bdi.jpg