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If you like making your own compost here is a nice list of compost bin plans and they are all free. Making compost is not difficult and it doesn’t have to be expensive. I have made plenty of compost just using piles. Keep the compost moist but not to wet and turn frequently for good and faster results.
Free Compost Bin Plans & Ideas
 Cinder Block Compost Bin Plans This cinder block compost bin is designed to last. The cider block should be fine and work good the way it is, but if you think the holes on the cinder block are to large consider adding wire mesh to the walls. This design allow you to build one or more side by side for a nice appearance. Source: MyBackyardPlans| Fix Link |
 If you are making your own compost, here are plans for a compost sifter. This sifter will remove any large particles that still need to compost and leave you with beautiful compost that will be ready to use. Source: MyBackyardPlans | Fix Link |
Noted on many of your plans is the use of treated wood. Stop recommending this. The chemicals from the treated wood leach into the compost ruining the hard work of people and the compost.