Tim, funny you should ask about a mini UDS. I just finished one this past weekend to the point of being able to use it. I still need to paint it and get a proper grate for it but it worked to perfection on an 8 lbs boston butt. Because it isn't as tall as a 55 gal drum you'll need to save some space anywhere you can. I drilled my intake holes as far down the drum as I could, at this point I'm just using magnets to cover them to restrict airflow. I made my charcoal grate out of a perforated pizza pan which sits 1" off of the bottom of the drum. My grill grate sits 21 3/4" above the bottom of the charcoal grate. That gives me 5 1/2 " to the lid which I pounded into a slight dome shape, so i've got maybe 6 1/2" clearance in the dead center of the smoker. I drilled eight 1" holes for exhaust although I think this might have been a bit much as I had to run it with all of the intakes almost completely closed. I suspect that with that many large holes in the lid it was letting some fresh air into the drum. Having said that though it kept temps between 230-240 all day until I shut it down which was about 9 hours and only used about half of the maybe 7 lbs of lump charcoal that I put in it.
Some of my decisions on where to drill and how big were made because of some small gashes in the sides and lid of the drum that I was given, but I can't argue with the product that it turned out and it was only my first smoke on it. I did do a long practice smoke with nothin more than a couple of pieces of bacon on it the afternoon and evening before and it kept the temps exactly where you'd want them for 10 hours using cheap Wal-Mart briquettes from a bag that had been standing open for a month or so.
Hope some of that helps.
Last edited by Wyley; 06-18-2009 at 08:39 PM..