i'm going to replace the old green plastic one with something that actually works. the unfortunate problem with the plastic bins is they don't aerate very well. once the anaerobic activity gets going it interferes with the breakdown and the organic matter starts to rot instead of composting. the other thing that can happen is not enough moisture, or too much heat. this can affect the breakdown process and the microbial action.
so the answer is to build a bin with wooden slats, have gaps between the boards to allow air to circulate and turn the compost as and when needed. a good compost that is breaking down well does NOT smell. if anything it has that rich sweet smell of live soil, and worms abound in plenty. a lid is good though to keep vermin out, and for aesthetics.
these are some designs i am considering. placed a WANTED post on Freecycle tonight and have managed to locate some old pallets for the timber.
Vasili on SBS has detailed instructions for building a wooden compost pallet bin, including a video clip.
This three-bin structure is the rolls royce of compost bins, complete with detailed instructions and photographs. Even management students from Bucknell University can build one so it can't be that hard.
And this is my favourite, the twin bin, portable and compact. The instructions are clearly laid out, step-by-step with photos.
Watch this space as i begin to construct my own variation and combination to fit the space where the plastic bin sits.