Here is a pic of the one I made. 12" tall, 2 - 12" x 24" pieces of expando wired to a 13" charcoal grate with 12 gauge copper wire. The expando is bolted together and the handle is made from some flat stock that was kicking around. The ash catcher is made from a 30 gal. barrel cover and is bolted to the charcoal basket with 3 1/2" long carriage bolts.
It does certainly not need to be 12" tall, but I will never have the need to add any charcoal in the middle of a cook with it being that tall.