Seldom are "weed" seeds killed by compost temperature, although that has been a common misunderstanding for many years, probably pertetuated because someone took some compost and put it in an oven to see what tmperature would kill "weed" seeds. Some few brave researchers have actually looked at what happens and are trying to get that information out and what they have found is those "weed" seeds actually germinate, in that nice enviroment the compost provides, and then due to lack of sunlight, die.
Sometimes it can be difficult to get the temperature in my 64 cubic foot bins that high so with even less volume it would be even more problematic.

2 minutes of googling finds this...

"Mortality of weed seeds at temperatures of 39, 42, 46, 50, 60, and 70 C was recorded through time under controlled
laboratory conditions similar to those of soil solarization for six weed species: annual sowthistle, barnyardgrass, black nightshade, common purslane, London rocket, and tumble pigweed. Time and temperature requirements for thermal death varied considerably among the species studied. Barnyardgrass, London rocket, and annual sowthistle were more susceptible to heat treatment than black nightshade, common purslane, and tumble pigweed. Temperatures of 50 C and above were lethal for seeds of all species." (my bold)

50C = 122F

Lloyd

Here is a link that might be useful: Time and Temperature Requirements for Weed Seed Thermal Death

My tumbler was 9.5 cubic feet, and I could get 160F after two or three days, with a fair amount of effort. No luck the first three tries, then I started weighting everything I put in the tumbler; as well as filling it up in one day.

The tumbler center bar rusted thru after four years, but by then I have given up using it. The mesh bins hold lot more, cost $17 instead of $350, and are easier to use for me.

It seems that with exception of esthetic reasons and perhaps township regulation forbidding having compost piles, it make no sense having small compost tumblers. When a ordinary plastic barrel is priced 150$+ and barely make compost (far cry from advertised 2 weeks) and the cheaper alternative does (much) better it is clear that the compost tumbler industry is taking advantage. There is very little chance purchasing a small tumbler would make economical justification.
People here are clearly experienced but when troubleshooting the advices are very vague: maybe it is too wet, no wait could be too dry, you have to turn more or add more green or more brown etc. For those$150+ tumblers they might have placed some kind of moisture/nitrogen indicator  for idiots like me. I bought 4-in-1 Soil Tester few months ago, cost about 10$ it can measure pH, soil fertility, soil moisture, and sunlight, so if something like that could be incorporated that would be a cool product .
Or just do a 17$ mesh bin and make five times as much compost inteadÂ

Often, the troubleshooting is very vague because it is difficult to diagnose problems over the 'net. On occasion, the advice comes from people who have never used a tumbler and just use their stock answers to every problem. I don't have a small tumbler so I am not knowledgable about the temperatures they get to.

I could give some other reasons for small tumblers off the top of my head;

-small family, don't need a large tumbler.
-animal issues (rats, racoons etc etc)
-want it close to the house to supplement a large bin in the back

I'd bet others will come up with lots more possible reasons.

Economics isn't everything to everyone, I spend money on composting that a lot of people would (and do) consider a waste. (As an aside, I wouldn't spend a dime on golfing, doesn't make sense to me to hit a ball and then chase after it just to keep hitting it further away. But I also understand and accept that millions enjoy this pastime, go figure!)

Lloyd

My family is small (just me and the dog) but I was dragging home 600 pounds of bok choy from the grocery and 100-200 pounds of used coffee grounds. Not at first, but after the fifth mesh bin compost pile.

On the subject of animal issues, that is one reason (a minor one) I was happy to switch from tumbler to large mesh bin. While the tumbler was a 'closed' type compost pile, it does have some venilation holes.

I often put smelly bluegill parts into the core of a 130F+ pile, and have no odor or animal problems at all. These mesh bins are 1/4" mesh hardware cloth, 4' in diameter, and 24" or 30" tall.

My compost pile has not been above the outside air temperature for years. What happens with weed seeds is they sprout into a plant, plants get turned over, and then they they die.

A few things you can try although that is a very small volume to work with. 1- try getting a 1.5" thick foam insulating sheet and wrap it around the vessel. 2- Batch compost all at once using a 30-1 carbon- nitrogen ratio. 3-Chop materials to 1/2 inch or smaller and only use rapidly degrading materials. Grass clippings, ucg, chopped brown leaves, chopped straw etc.

Here is a pic of a large composter and cover
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Hi, I just bought a used cmp03 composter. I have a question. There are several smaller holes in it for aeration. But there are also 2 larger holes in it. When I spin it on the ground the compost material comes out of those holes. Is there supposed to be plugs in those holes or something to keep the material in there? I called the company but they didn't know. Thought someone that actually had one would know. I am new to composting so not real sure of what I'm doing. Thanks

I bought three 10 cubic yard truckloads of compost from a "certified" compost maker. Being certified they supposedly were required to measure the temperature of their huge piles twice a day. They were associated with a horse stable that at the peak had 220 horses supplying manure for their piles, which they mixed with the wood shavings bedding. So they knew what was going into their compost and controlled every step.
It was good stuff, didn't smell and didn't attract flies, and was double screened so didn't have any of the usual plastic bags, soda cans, and broken glass you often find in commercial compost.
That said, even though they claimed it was weed free I have more weeds coming up on my property than any of my neighbors, particularly in areas where I spread the compost. Most annoying is some tall, coarse meadow grass that has sprouted all over my property, and I am the only one in the area that has this so I am sure it came from viable seeds in the compost.
So if even the best stuff one can buy made in piles six to eight feet high and containing hundreds of cubic yards can't get the compost hot enough to kill grass and weed seeds, I don't see how a little drum containing maybe one cubic yard maximum could get hot enough.