First off though you'll need a few things :
210l Used Oil Drum, if you can find one with an open top even better, if not you'll have to do a bit of cutting but it isn't a big issue. Just make sure it has no inner lining.
57cm Charcoal Grill
18.5" weber charcoal grate or if you are can make one out of expanded metal
2 Pieces of Expanded Metal in the following size 30cm x 60cm
Some Highheat paint.
3 3/4" Steel Nipples
2 3/4" Steel Caps
A temperature gauge, the Jetmaster ones work quite well.
A handle for the lid
Assorted nuts and bolts
One the drums are painted, assemble the charcoal basket by bending the Expanded metal sheets into two half moons and then attaching them to each other and the 18,5" charcoal grate. I used wire to do this, but if you are handy with a welder you can always weld them together. I also made a handle with wire to help get the charcoal basket in and out of the drum without hassle.
Next I drilled some holes and added the handle to the lid.
Here you can see the charcoal basket fits easily inside the drum, and you'll also see the nuts and bolts I'm using to hold the 57cm grill in place.
I drilled out three 25mm holes using a steel cutting drill bit for the three 3/4" steel nipples, I attached the two steel caps and ballvalve on the nipples. Last step is to just drill a hole slightly undernear where the 57cm grill comes and install the temperature gauge there.
I later added a 42cm ash catchpan underneath the charcoal basket to make cleaning easier. After assebly is done, the first thing you want to do is season the UDS or give it a dry run.
Essentially you start up a fire with wood chips and charcoal mixed in the charcoal basket so you can test if the smoker works right before possibly wasting any meat. And you also give it a bit of flavoring,
Once all that is done you are ready to smoke your meat!
If you have fine wood shavings or wood chips I suggest using small tinfoil pans covered in tinfoil with holes to hold the wood chips in between the charcoal. Otherwise the wood chips burn out too quickly.
My UDS in action
And the end result, pork shoulder smoked with cherry wood for 8 hours at 120C in my UDS, we pulled the bone clean out. After this our hands got a bit too sticky to use the camera.
But there you go, if someone like me with absolutely no DIY skills can build one, so can you. If you are looking for the dry rub and basting sauce recipe I used feel free to ask in the comments. I'll share it here if enough people are interested.