Compost Tumbler TypesThere are four basic types of compost tumblers:
Center-axle Mounted Drums.This type of tumbler also sits on a frame above the ground. A vertically mounted barrel rotates around a central axle, something like a ferris wheel. To operate it you simply spin the drum, which is usually not too much effort. Some units have doors on both ends, making it easier to load and unload the unit. Instead of internal baffles the central axle mixes the materials. Most of these tumblers are mounted low to the ground, making the unloading process a little more difficult if you are trying to put it in a wheelbarrow
Commercially available center axle drums include The Green Machine, The Urban Compost Tumbler (UCT), the Tumbleweed, and
Base Mounted Rolling Rrums.
A horizontally configured drum rolls on a ground-level base. Some of them actually have rollers, while others have molded rounded points to suspend the drum and let it rotate. Obviously, the tumblers with rollers are easier to turn. Some of these drums of this style have steps molded into the body, so you can pus it with your feet and legs to turn it, which is good because if it is a model that does not have rollers it would be fairly difficult to turn by hand.
Some models can be taken off the base, and set upright to load. However, unloading them can be difficult. It's simple to roll it do the garden and dump the contents, but it is hard to unload into a wheelbarrow.
Commercially available drums include the the Compost Mixer, the Eco-Cycle Base tumbler, the Step-down Composter and the EZ Composter .
BluePlanetSmart Compost Tumbler
is a rolling sphere that's similar to the drums.
Envirocycle Composter & Compost Tea Maker
is not only a rolling drum design but it includes a compost tea maker that captures the tea in the base that the drum is mounted on.
Rolling SpheresLarge molded plastic balls that you roll around the yard after they are filled with composting material. These can be somewhat unwieldy to move. Since they are on the ground they can be filled rather easily, but can be harder to empty.
These roll-around composters are not generally true spheres, but have sides like a geodesic dome. So, instead of rolling like a basketball, they tend to veer side to side somewhat, making it a little difficult to roll them in the directions you want, a little like walking your dog.
The Bio Orb and the Large Batch Composter are examples of this style.
Crank-operated Drums.These are the top of the line units, built with a horizontally mounted drum resting on raised frame, it will have a crank assembly to let you turn the drum easily. Generally there are internal baffles which mix the composting material.
The drums are fairly high, which can make some work for loading the material. To empty one is easier, as the compost simply pours out.
These crank operated units can be more expensive than other types of tumblers. In this case, you get what you pay for, as these are also the easiest to operate.
Commercially available crank operated compost tumblers include The Mantis ComposTwin (has 2 drums) and the ComposTumbler