Here are the measurements:
The long axis of the base supports = 50" end to end
The width at the base supports are 23" wide from outer edge to outer edge
The height is 75" to the top shelf
Each shelf is 14" wide from the vertical support it's welded to
The first shelf is 24" form the ground, the second is 50", the top is 75"
It's all 2" tube steel with 1.5" angle iron and flat bar
Adjustments I plan to make now that I've made 3 batches on it:
I will put some sheet metal on the vertical to shield the mash tun cooler from the HLT burner, it's melted the top of the cooler quite nicely - I'll just sheet metal screw it to the vertical supports
I will probably fashion some way to raise the burners closer to the bottom of the vessels - probably just a piece of bent metal that can be affixed to the current support piece that raises them 2" or so.
Other than that I am unbelievable happy with it. I've been thrilled to be able to run more than one burner at a time to multi-task and I love being able to sparge while heating my second water additions and to drain the wort right into the kettle already under fire which saves a lot of time from previous methods
My friend who helped me is a mechanical engineer, blacksmith, artisan metal worker/fabricator - so he did the welding and most of the hard parts, but this is totally do-able by anyone with some modest skills - go for it! I did the basic design, and all of the burner plumbing and placement, which was a blast as well.
Go for it and let me know how yours turns out!