Several years ago I attended a composting class and was able to purchase two compost bins that were basically 10-12 foot long rolls of heavy duty plastic with 3 inch holes scattered around the length of the roll. You created a cylinder from the roll, using bolts and wing nuts and had a simple, inexpensive compost bin. It was about 3 feet high. I'm looking to buy two more and having a hard time finding anything the same size and sturdy enough to not need posts to hold the sides up. Does anyone have any suggestions of a gardening supply place that sells something like this? Thanks