I built one because the rich food waste that was going into the Pentagon composter was causing smell and fly problems. Hopefully the tumbler will solve that.
There are several instructables showing good ways to make a tumbler. There isn't a bad way to make one. I threw this one together in about an hour.
Step 1: Mark the Axle Pivot Holes
Mark the barrel and the cut the string so it just reaches around.
Fold the string in half and mark the midpoint.
Wrap it around the barrel again and mark the other side of the barrel where the string midpoint falls.
You now have two spots marked that are directly opposite each other.
Now measure down from the edge to each spot and make sure they are centered vertically as well as circumferentially.
Step 2: Drill the Pivot Holes
The top will be a bit heavier than the bottom due to the door hinges etc. at the top.
Step 3: Cut the Top Off
Save the part you cut off. That's going to be a lid.
Step 4: Lid Hinge Rod
Step 5: Make the Pillars
A couple of posts pounded into the ground will also work to support your tumbler's axle.
I had some pieces of welded square frame sitting around that were perfect, so I used them. I welded the U-shaped piece to the rectangular frame. I used the solar-powered golf cart welder with a spoolgun to do the welding. I used .030" fluxcore wire at 24 volts, the wirefeed was run on 18 volts.
I did 4 tack welds and was done. That was quick!
Step 6: Drill Axle Holes in the Pillars
I had the right size hole saw so I used that. I used plenty of oil so the cutter didn't clog or overheat.
Step 7: Install Axle Retaining Pins
This will keep the axle from wiggling out of the supports.
This is the usual way I retain the wheels on a land yacht.
Step 8: Perforations!
I'll probably have to drill bigger holes than this to get proper airflow.