Seems the need for a basic build tutorial.
Let me say, i am not the inventer of the UDS. I learned from many masters before me, but have built and cooked enough on them to know how they work!

Here's your basic build for a UDS.

Start by dividing your drum into 3 segments and draw a level line from top to bottom.

Now mark and drill 1" holes, 2" from the bottom for your intakes. The step bits are nice but expensive. I prefer a good 1" holesaw. I can get about 3 barrels cut before the bit fails.

Mark 7" from the top and drill 1/4" holes for the cooking grate bolts

I use 1/4" x 2" bolts for my grate support

Install 3-3/4" close nipples (thread right into a nicely cut hole) with caps and a 3/4" ball valve for your intakes.
I have actually switched over to magnets for this.
Cheaper and no rust/ knock-off problems.

By imn88fan

Firebasket consists of a 12" x 24" piece of expando that was cut in half, rolled and fastened in a circle and attached to a grate with 3-3 1/2x3/8 bolts installed as feet to keep the basket off the bottom of the barrel for better circulation. I find the 17" Weber charcoal grates work the best for this!

A Weber 22 1/2" replacement grate works best but the $9.00 knock-offs work fine.

By imn88fan

Exhaust can be either the 2" bung in the lid or drill 8 1/2" holes evenly spaced around the lid.

By imn88fan

Shelf mod...a couple of 4" shelf brackets work great!

Handles and an 8" piece of PVC for an exhaust...(check the dollar store for these handles!)

Weber Kettle lid and fat mans intake extension handle mod...

Don't let the simplcity fool ya, drums do VERY well at comps.!

By imn88fan

I will attempt to add a full parts list soon but as you can see, especially if you go the magnet route, you can build a nice smoker for under a hundred bucks!